tag:blogger.com,1999:blog-83786417076071780112024-02-07T06:52:45.196-07:00Venus DispatchesThe latest research on Venus.Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.comBlogger29125tag:blogger.com,1999:blog-8378641707607178011.post-48580835508789067612017-05-08T20:54:00.000-07:002017-05-08T20:54:43.507-07:00Quick Look: The Thermal Structure of the Venus Atmosphere<br />
<h3>
Summary</h3>
<div>
For two years beginning in 2013, a large team led by Sanjay Limaye set out to combine and compare the following:<br />
<ul>
<li>Venusian atmospheric data collected by probes in the 1970s and 1980s (used to create the Venus International Reference Atmosphere, or VIRA)</li>
<li>Venus Express data on the vertical and horizontal structure of the atmosphere</li>
<li>Earth-based observations of the upper atmosphere temperature structure of Venus made since VIRA</li>
</ul>
</div>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEUVgwPuclpzJhe0kdalE6pxPAadGE2bKXY3N72zh2d2twfZ6jj4SMrXEBH_DXTmuk78fvH_C4qOWhZNfoPcpAFjrIEm7puBbti07jzLOSgaMDfaWQa1CKFqVIp7cxCIoi9FpqaAzk2bWN/s1600/venus_vertical.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="312" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEUVgwPuclpzJhe0kdalE6pxPAadGE2bKXY3N72zh2d2twfZ6jj4SMrXEBH_DXTmuk78fvH_C4qOWhZNfoPcpAFjrIEm7puBbti07jzLOSgaMDfaWQa1CKFqVIp7cxCIoi9FpqaAzk2bWN/s400/venus_vertical.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Figure 1a: Vertical coverage of post-VIRA atmospheric structure experiments.</td></tr>
</tbody></table>
<br />
This work is seen as the first step toward creating an updated VIRA model. You can read it <a href="http://www.sciencedirect.com/science/article/pii/S0019103516307138">here.</a><br />
<br />
<h3>
Reference:</h3>
<ul>
<li>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2017.04.020&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+Thermal+Structure+of+the+Venus+Atmosphere%3A+Intercomparison+of+Venus+Express+and+Ground+Based+Observations+of+Vertical+Temperature+and+Density+Profiles&rft.issn=00191035&rft.date=2017&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103516307138&rft.au=Limaye%2C+S.&rft.au=Lebonnois%2C+S.&rft.au=Mahieux%2C+A.&rft.au=P%C3%A4tzold%2C+M.&rft.au=Bougher%2C+S.&rft.au=Bruinsma%2C+S.&rft.au=Chamberlain%2C+S.&rft.au=Clancy%2C+R.&rft.au=G%C3%A9rard%2C+J.&rft.au=Gilli%2C+G.&rft.au=Grassi%2C+D.&rft.au=Haus%2C+R.&rft.au=Herrmann%2C+M.&rft.au=Imamura%2C+T.&rft.au=Kohler%2C+E.&rft.au=Krause%2C+P.&rft.au=Migliorini%2C+A.&rft.au=Montmessin%2C+F.&rft.au=Pere%2C+C.&rft.au=Persson%2C+M.&rft.au=Piccialli%2C+A.&rft.au=Rengel%2C+M.&rft.au=Rodin%2C+A.&rft.au=Sandor%2C+B.&rft.au=Sornig%2C+M.&rft.au=Svedhem%2C+H.&rft.au=Tellmann%2C+S.&rft.au=Tanga%2C+P.&rft.au=Vandaele%2C+A.&rft.au=Widemann%2C+T.&rft.au=Wilson%2C+C.&rft.au=M%C3%BCller-Wodarg%2C+I.&rft.au=Zasova%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CGeosciences%2CEarth+and+Planetary+Astrophysics%2C+Atmosphere+Science%2C+Planetary+Science">Limaye, S., Lebonnois, S., Mahieux, A., Pätzold, M., Bougher, S., Bruinsma, S., Chamberlain, S., Clancy, R., Gérard, J., Gilli, G., Grassi, D., Haus, R., Herrmann, M., Imamura, T., Kohler, E., Krause, P., Migliorini, A., Montmessin, F., Pere, C., Persson, M., Piccialli, A., Rengel, M., Rodin, A., Sandor, B., Sornig, M., Svedhem, H., Tellmann, S., Tanga, P., Vandaele, A., Widemann, T., Wilson, C., Müller-Wodarg, I., & Zasova, L. (2017). The Thermal Structure of the Venus Atmosphere: Intercomparison of Venus Express and Ground Based Observations of Vertical Temperature and Density Profiles <span style="font-style: italic;">Icarus</span> DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2017.04.020" rev="review">10.1016/j.icarus.2017.04.020</a></span>
</li>
</ul>
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-45890267961507175512017-04-26T20:33:00.000-07:002017-05-08T19:43:29.610-07:00Recently Active Lava Flows on Idunn Mons<br />
<br />
<h3>
Overview</h3>
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjrlTEcdDfbKdOogGIf23wgqfUbkoVPWq3bADHJlFuNJ3iF5ef7FreNWSzrEARLR_gSW02knUyJO9Bsn5ud13-HG86UArv9867GZL4oCU9HsCUo4OSFHl9kxKWA0z7MQ-pznPXpUN-CFsxP/s1600/IdunnMons.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="269" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjrlTEcdDfbKdOogGIf23wgqfUbkoVPWq3bADHJlFuNJ3iF5ef7FreNWSzrEARLR_gSW02knUyJO9Bsn5ud13-HG86UArv9867GZL4oCU9HsCUo4OSFHl9kxKWA0z7MQ-pznPXpUN-CFsxP/s320/IdunnMons.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Combined VIRTIS emissivity and Magellan SAR image of Idunn Mons</td></tr>
</tbody></table>
In <a href="http://www.sciencedirect.com/science/article/pii/S003206331630112X">Idunn Mons on Venus: Location and extent of recently active lava flows</a>, Piero D'Incecco and his colleagues looked closer at 1 µm thermal emissivity anomalies on the eastern flank of Idunn Mons, as observed by the VIRTIS instrument on Venus Express. Hypothesizing that recent lava flows were responsible, they overlayed the VIRTIS emissivity data with SAR images from the Magellan mission to look for lava flows that may have resulted in the high emissivity.
They created a geologic map of lava flow units on the eastern flank, creating outlines on Magellan SAR images. They then used software that models the best fit of emissivity data to the flow areas.
<br />
<br />
<h3>
What Did They Find?</h3>
They conclude that the lava flow units on the eastern flank of Idunn Mons are likely responsible for relatively high 1µm emissivity observed by VIRTIS. This is consistent with their reconstructed stratigraphy (i.e., relative ages) of the various lava flow units. They also note that the average microwave emissivity of the lava flows is consistent with dry basalts (i.e., cooled volcanic rock), and also may indicate limited chemical weathering.
<br />
<br />
<h3>
Why Is It Important?</h3>
Their data are consistent with lava flows that are young enough that they have not experienced significant weathering, and may represent recent or even active volcanism on the surface of Venus. The authors look forward to new data to be collected by <a href="https://science.jpl.nasa.gov/projects/VERITAS/">VERITAS</a>, a Discovery Program finalist mission that sadly, was not selected.
<br />
<br />
<h3>
References:</h3>
<ul>
<li><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Planetary+and+Space+Science&rft_id=info%3Adoi%2F10.1016%2Fj.pss.2016.12.002&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Idunn+Mons+on+Venus%3A+Location+and+extent+of+recently+active+lava+flows&rft.issn=00320633&rft.date=2017&rft.volume=136&rft.issue=&rft.spage=25&rft.epage=33&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS003206331630112X&rft.au=D%27Incecco%2C+P.&rft.au=M%C3%BCller%2C+N.&rft.au=Helbert%2C+J.&rft.au=D%27Amore%2C+M.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CGeosciences%2CEarth+and+Planetary+Astrophysics%2C+Planetary+Science">D'Incecco, P., Müller, N., Helbert, J., & D'Amore, M. (2017). Idunn Mons on Venus: Location and extent of recently active lava flows <span style="font-style: italic;">Planetary and Space Science, 136</span>, 25-33 DOI: <a href="http://dx.doi.org/10.1016/j.pss.2016.12.002" rev="review">10.1016/j.pss.2016.12.002</a></span></li>
</ul>
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-21735981343097959122017-04-21T09:02:00.003-07:002017-05-08T19:40:04.008-07:00Spectral Guide for Earth-based Observers to Complement Akatsuki Mission<br />
<h3>
Overview</h3>
Meant as a guide for Earth-based observers of Venus (professional and amateur), <a href="http://www.sciencedirect.com/science/article/pii/S0019103516305851">Overview of useful spectral regions for Venus: An update to encourage observations complementary to the Akatsuki mission</a> provides detailed information regarding the wavelengths at which observations should be made to complement the Akatsuki mission at Venus.<br />
<br />
Two tables (one for day side observing, the other for night side) provide opportunities across a "spectrum" of wavelengths, indicating what products are likely involved, the altitude being observed at that wavelength, and the suspected processes occurring there. Citations to previous work at the various wavelengths are also provided.<br />
<br />
The paper is available to all under a Creative Commons License.<br />
<br />
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjiDQ52zN2dbfJgmnSOW3_Y4_U491dpcvAZZD4njiunzEKwOIm_FaEuflpxy3IAie9EDnTb8Xc6yobDWX4LtRjJpBGVXsFGlzVTi8RXyXelAoK6qCZyQ0EIipssEW6GNkvzSdAM5wu2cNK/s1600/venus_wavelengths.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="372" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjiDQ52zN2dbfJgmnSOW3_Y4_U491dpcvAZZD4njiunzEKwOIm_FaEuflpxy3IAie9EDnTb8Xc6yobDWX4LtRjJpBGVXsFGlzVTi8RXyXelAoK6qCZyQ0EIipssEW6GNkvzSdAM5wu2cNK/s640/venus_wavelengths.jpg" width="640" /></a></div>
<br />
<h3>
<br />
References:</h3>
<ul>
<li><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2017.01.027&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Overview+of+useful+spectral+regions+for+Venus%3A+An+update+to+encourage+observations+complementary+to+the+Akatsuki+mission&rft.issn=00191035&rft.date=2017&rft.volume=288&rft.issue=&rft.spage=235&rft.epage=239&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103516305851&rft.au=Peralta%2C+J.&rft.au=Lee%2C+Y.&rft.au=McGouldrick%2C+K.&rft.au=Sagawa%2C+H.&rft.au=S%C3%A1nchez-Lavega%2C+A.&rft.au=Imamura%2C+T.&rft.au=Widemann%2C+T.&rft.au=Nakamura%2C+M.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CGeosciences%2CEarth+and+Planetary+Astrophysics%2C+Planetary+Science">Peralta, J., Lee, Y., McGouldrick, K., Sagawa, H., Sánchez-Lavega, A., Imamura, T., Widemann, T., & Nakamura, M. (2017). Overview of useful spectral regions for Venus: An update to encourage observations complementary to the Akatsuki mission <span style="font-style: italic;">Icarus, 288</span>, 235-239 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2017.01.027" rev="review">10.1016/j.icarus.2017.01.027</a></span></li>
</ul>
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-10567065518363322752017-04-18T09:43:00.001-07:002017-05-08T19:35:55.441-07:00Bright highlands in equatorial Venus likely ferro-electric. What's up with the high-latitude highlands? <br />
<br />
<h3>
Overview</h3>
A lot of papers have been written about the highly reflective highlands (in radar) on Venus, with several different hypotheses (e.g. high porosity, metal frost). Allan Treiman, Elise Harrington, and Virgil Sharpton look specifically at high-latitude highlands in comparison to highlands in the equatorial regions. Both areas feature high reflectivity, but the reflectance patterns are distinct, as they describe in <a href="http://www.sciencedirect.com/science/article/pii/S0019103516303633">Venus' radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes</a>.<br />
<br />
<h3>
What Did They Find?</h3>
They have confirmed earlier studies showing that the reflectance pattern seen in equatorial highlands <br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqf1tNp1sJvkzg9coD0zeFWGmCZGfxHTDGJ_u8kqNNnm3P-yPfgbKb3yGHQaDT3ooFNOb5isqqeKVZ4K-nAqI4efrU7aTHgUvW-bs4gV0MgmXVSO1_Y5npYTTwLzLMYdHCO-o2tS9rtpm9/s1600/snowline.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="212" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqf1tNp1sJvkzg9coD0zeFWGmCZGfxHTDGJ_u8kqNNnm3P-yPfgbKb3yGHQaDT3ooFNOb5isqqeKVZ4K-nAqI4efrU7aTHgUvW-bs4gV0MgmXVSO1_Y5npYTTwLzLMYdHCO-o2tS9rtpm9/s320/snowline.jpg" width="320" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">"Snow Line" from N flank of Maxwell Montes (from Fig. 4c)</td></tr>
</tbody></table>
(such as Ovda Regio) are consistent with a ferro-electric substance, likely chlorapatite.<br />
<br />
The reflectance patterns on Maxwell Montes (~60°N) are different. The backscatter abruptly transitions from low to high at the previously identified "snow line" (~4.5km elevation), and stays high above that point.<br />
<br />
They believe this pattern indicates a semiconductor material. How did it get there? Either by precipitation from the atmosphere (frost?), or it formed as the result of a chemical reaction between the surface and atmosphere.<br />
<br />
<h3>
Why Is It Important?</h3>
At the very least, their research shows that even though the highlands of Ovda Regio (equatorial) and Maxwell Montes (high latitude) are similarly reflective, they are caused by different materials or processes.<br />
<br />
The authors urge (and I agree) that lander missions with geochemical analysis instruments be sent to multiple highland locations.<br />
<br />
<h3>
References:</h3>
<ul>
<li><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2016.07.001&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus%E2%80%99+radar-bright+highlands%3A+Different+signatures+and+materials+on+Ovda+Regio+and+on+Maxwell+Montes&rft.issn=00191035&rft.date=2016&rft.volume=280&rft.issue=&rft.spage=172&rft.epage=182&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103516303633&rft.au=Treiman%2C+A.&rft.au=Harrington%2C+E.&rft.au=Sharpton%2C+V.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CGeosciences%2CEarth+and+Planetary+Astrophysics%2C+Planetary+Science%2C+Geochemistry">Treiman, A., Harrington, E., & Sharpton, V. (2016). Venus’ radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes <span style="font-style: italic;">Icarus, 280</span>, 172-182 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2016.07.001" rev="review">10.1016/j.icarus.2016.07.001</a></span>
</li>
</ul>
<br />
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-56982924045229439772017-04-16T21:20:00.000-07:002017-04-16T21:24:11.080-07:00Discovery of a 150 day period in the Venus condensational clouds<h3>
Overview</h3>
<div>
Using near infrared (NIR) data from the VIRTIS instrument that once traveled aboard the Venus Express spacecraft, Kevin McGouldrick and Constantine C. C. Tsang found a periodic variation in radiance, most intense at the mid-latitudes. The paper is <a href="http://www.sciencedirect.com/science/article/pii/S0019103516306522">here</a>.</div>
<div>
<br /></div>
<h3>
What Did They Find?</h3>
<div>
They identified A 150-day periodic variation in radiance within the 1.74 µm and 2.30 µm windows, which is most pronounced between 30° and 60° latitude. They also found that in these mid-latitudes, radiance at these wavelengths steadily increased throughout the life of the instrument. </div>
<div>
<br /></div>
<h3>
Why Is It Important?</h3>
<div>
The 150-day timescale is consistent with a model (developed by McGouldrick) of the Venusian condensational clouds vertical structure, driven by radiative-dynamical feedback. I'm not sure what that means, but thank goodness the paper is open source!</div>
<div>
<br /></div>
<h3>
References</h3>
<ul>
<li><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2016.10.005&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Discovery+of+a+150+day+period+in+the+Venus+condensational+clouds&rft.issn=00191035&rft.date=2017&rft.volume=286&rft.issue=&rft.spage=118&rft.epage=133&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103516306522&rft.au=McGouldrick%2C+K.&rft.au=Tsang%2C+C.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">McGouldrick, K., & Tsang, C. (2017). Discovery of a 150 day period in the Venus condensational clouds <span style="font-style: italic;">Icarus, 286</span>, 118-133 DOI: <a rev="review" href="http://dx.doi.org/10.1016/j.icarus.2016.10.005">10.1016/j.icarus.2016.10.005</a></span>
</ul>
<div>
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</div>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-10662510082745124822017-04-16T20:22:00.001-07:002017-04-16T20:23:33.943-07:00Venus Research at LPSC 2017<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5M88yfnTyt0y2ZQbvW4otznAUvFshH024Kl2j9zjqJSlNdFtMUVhas6RsifXGW2Pq6Daz7IxaOTaxhCHuY23CKZPj0aQP35Z5ncrvbYOVGpSTWCYqyP0Jjgn7wcK-R72H9_5uGSA_2pC2/s1600/lpsc.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="102" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5M88yfnTyt0y2ZQbvW4otznAUvFshH024Kl2j9zjqJSlNdFtMUVhas6RsifXGW2Pq6Daz7IxaOTaxhCHuY23CKZPj0aQP35Z5ncrvbYOVGpSTWCYqyP0Jjgn7wcK-R72H9_5uGSA_2pC2/s320/lpsc.jpg" width="320" /></a></div>
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<br />
Thursday afternoon at #LPSC2017 was Venus time! Thirteen oral presentations were presented, including topics such as:<br />
<ul>
<li>Atmosphere observed by NASA's SOFIA Telescope</li>
<li>Metal frost</li>
<li>Recent volcanism</li>
<li>Earth-based Experiments & Modeling</li>
</ul>
<div>
You can <a href="https://www.hou.usra.edu/meetings/lpsc2017/pdf/sess557.pdf">read the program</a> which includes links to all the abstracts.</div>
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<br /></div>
<div>
Posters, too! Yes, there were a 28 posters dealing with science and future exploration of Venus. The <a href="https://www.hou.usra.edu/meetings/lpsc2017/pdf/sess609.pdf">program with links to abstracts</a> are available for these, too.</div>
<div>
<br /></div>
<div>
Six of these posters were <a href="https://www.hou.usra.edu/meetings/lpsc2017/eposterindex.cfm">uploaded to the LPSC website for you to see</a>. Here are direct links to two of them:</div>
<div>
<br /></div>
<div>
<br />
<ul>
<li><a href="https://www.hou.usra.edu/meetings/lpsc2017/eposter/1015.pdf">Actively Cooled Venus Lander Instrument Payload Using a Multi-Cascade Refrigeration Cycle</a></li>
</ul>
<ul>
<li><a href="https://www.hou.usra.edu/meetings/lpsc2017/eposter/2782.pdf">Morphometry of Mid-Sized Venusian Shield Volcanoes</a></li>
</ul>
</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-38711618649501053732015-08-05T22:22:00.001-07:002015-08-05T22:22:39.789-07:00Best evidence yet for active volcanism on Venus?<br />
<h4>
Overview</h4>
In an <a href="http://onlinelibrary.wiley.com/doi/10.1002/2015GL064088/full">article</a> from <i>Geophysical Research Letters</i>, a team led by Eugene Shaygin used images taken by the Venus Monitoring Camera (VMC) aboard Venus Express to identify transient hot spots on the surface. These hot spots are located near very young (~10 Mya) volcanoes and rifts, and are suggestive of active lava flows.<br />
<br />
Even though the surface is generally obscured from view by the thick clouds, there is a transparent window through which light can pass in the near infrared wavelengths, and the VMC can capture images near 1 μm.
<br />
<br />
<br />
<h4>
What Did They Find?</h4>
Examining VMC images of the Atla Regio region, the research team identified bright spots, i.e., areas where the local emissivity was significantly higher. These hot spots were first seen in VMC images from June 2008, and were gone again by October.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1VUZ-F6_AZ3UUH78un3hL3UkaG81otPbDqh6Xd-FHq-zvyruXw2CsxaHG5SZZZRADRp2-BDhVE_krHejbGQB83chFbSLwZ10OvOiRLsmtTdpMBYYHgvzOOXVRFsiMVN1RR5ibrAHR2UwO/s1600/hotspots.png" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="224" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1VUZ-F6_AZ3UUH78un3hL3UkaG81otPbDqh6Xd-FHq-zvyruXw2CsxaHG5SZZZRADRp2-BDhVE_krHejbGQB83chFbSLwZ10OvOiRLsmtTdpMBYYHgvzOOXVRFsiMVN1RR5ibrAHR2UwO/s640/hotspots.png" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">VMC images of Ganiki Chasma showing transient hot spots</td></tr>
</tbody></table>
They believe they have eliminated other possible sources for these hot spots, and they are confident the spots represent an increase in the surface temperature.<br />
<br />
As additional supporting evidence, they point to Magellan spacecraft radar imagery. Radar-dark parabolas are seen around impact craters on Venus, and are understood to represent deposited ejecta from the impact (more here in this <a href="http://www.venusdispatches.com/2015/07/impact-crater-ejecta-mantling-on.html">paper by Campbell et al.</a>). These parabolas are associated with the youngest impact craters, and believed to be among the youngest visible features on the planet. Magellan images of the same location show that the ejecta parabola associated with crater Stillwell is interrupted by what could be lighter colored lava flows that would post-date the fairly recent ejecta.<br />
<br />
The authors believe these hot spots are volcanic in origin, and the body of evidence suggests that Venus is currently geodynamically active.
<br />
<br />
<h4>
Why Is It Important?</h4>
If there are active volcanoes on Venus, it would be invaluable for future comparative studies of rocky worlds with ongoing volcanism. It could shed light on why the Earth and Venus evolved so differently, and help us learn more about the Earth in the process.
<br />
<br />
<h4>
References:</h4>
<blockquote>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Geophysical+Research+Letters&rft_id=info%3Adoi%2F10.1002%2F2015GL064088&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Active+volcanism+on+Venus+in+the+Ganiki+Chasma+rift+zone&rft.issn=00948276&rft.date=2015&rft.volume=42&rft.issue=12&rft.spage=4762&rft.epage=4769&rft.artnum=http%3A%2F%2Fdoi.wiley.com%2F10.1002%2F2015GL064088&rft.au=Shalygin%2C+E.&rft.au=Markiewicz%2C+W.&rft.au=Basilevsky%2C+A.&rft.au=Titov%2C+D.&rft.au=Ignatiev%2C+N.&rft.au=Head%2C+J.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Shalygin, E., Markiewicz, W., Basilevsky, A., Titov, D., Ignatiev, N., & Head, J. (2015). Active volcanism on Venus in the Ganiki Chasma rift zone <span style="font-style: italic;">Geophysical Research Letters, 42</span> (12), 4762-4769 DOI: <a href="http://dx.doi.org/10.1002/2015GL064088" rev="review">10.1002/2015GL064088</a></span>
<br /><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2014.11.025&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Evidence+for+crater+ejecta+on+Venus+tessera+terrain+from+Earth-based+radar+images&rft.issn=00191035&rft.date=2015&rft.volume=250&rft.issue=&rft.spage=123&rft.epage=130&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS001910351400654X&rft.au=Campbell%2C+B.&rft.au=Campbell%2C+D.&rft.au=Morgan%2C+G.&rft.au=Carter%2C+L.&rft.au=Nolan%2C+M.&rft.au=Chandler%2C+J.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Campbell, B., Campbell, D., Morgan, G., Carter, L., Nolan, M., & Chandler, J. (2015). Evidence for crater ejecta on Venus tessera terrain from Earth-based radar images <span style="font-style: italic;">Icarus, 250</span>, 123-130 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2014.11.025" rev="review">10.1016/j.icarus.2014.11.025</a></span>
</blockquote>
<br />
<br />
<div>
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</div>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-70032558317500006542015-08-04T21:51:00.000-07:002015-08-04T21:51:31.992-07:00Quick Look: Vertical profiles of H2O, H2SO4, and sulfuric acid concentration at 45–75 km on Venus<p>An improved model for vertical profiles of water and sulfuric acid vapors as well as sulfuric acid concentrations in the Venus clouds is presented.
</p>
From the April 2015 edition of <i>Icarus</i>:<br />
<br />
<h4>
Title:</h4>
<blockquote class="tr_bq">
<a href="http://www.sciencedirect.com/science/article/pii/S0019103515000408">Vertical profiles of H<sub>2</sub>O, H<sub>2</sub>SO<sub>4</sub>, and sulfuric acid concentration at 45–75 km on Venus</a></blockquote>
<h4>
Abstract:</h4>
<blockquote class="tr_bq">
A method developed by Krasnopolsky and Pollack (Krasnopolsky, V.A., Pollack, J.B. [1994]. Icarus 109, 58–78) to model vertical profiles of H<sub>2</sub>O and H<sub>2</sub>SO<sub>4</sub> vapors and sulfuric acid concentration in the Venus cloud layer has been updated with improved thermodynamic parameters for H<sub>2</sub>O and H<sub>2</sub>SO<sub>4</sub> and reduced photochemical production of sulfuric acid. The model is applied to the global-mean conditions and those at the low latitudes and at 60°. Variations in eddy diffusion near the lower cloud boundary are used to simulate variability in the cloud properties and abundances of H<sub>2</sub>O and H<sub>2</sub>SO<sub>4</sub> . The best version of the model for the global-mean condition results in a lower cloud boundary (LCB) at 47.5 km, H<sub>2</sub>SO<sub>4</sub> peak abundance of 7.5 ppm at the LCB, and H<sub>2</sub>Omixing ratios of 7 ppm at 62 km and 3.5 ppm above 67 km. The model for low latitudes gives LCB at 48.5 km, the H<sub>2</sub>SO<sub>4</sub> peak of 5 ppm, H<sub>2</sub>O of 8.5 ppm at 62 km and 3 ppm above 67 km. The model for 60° shows LCB at 46 km, the H<sub>2</sub>SO<sub>4</sub> peak of 8.5 ppm, H<sub>2</sub>O of 9 ppm at 62 km and 4.5 ppm above 67 km. The calculated variability is induced by the proper changes in the production of sulfuric acid (by factors of 1.2 and 0.7 for the low latitudes and 60°, respectively) and reduction of eddy diffusion near 45 km relative to the value at 54 km by factors of 1.1, 3, and 4.5 for the low and middle (global-mean) latitudes and 60°, respectively. Concentration of sulfuric acid at the low and middle latitudes varies from ∼98% near 50 km to ∼80% at 60 km and then is almost constant at 79% at 70 km. Concentration at 60° is 98% at 50 km, 73% at 63 km, and 81% at 70 km. There is a reasonable agreement between the model results and observations except for the sulfuric acid concentration in the lower clouds. Variations of eddy diffusion in the lower cloud layer simulate variations in atmospheric dynamics and may induce strong variations in water vapor near the cloud tops. Variations in temperature may affect abundances of the H<sub>2</sub>O and H<sub>2</sub>SO<sub>4</sub>vapors as well.</blockquote>
<h4>
Full Citation:</h4>
<blockquote><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2015.01.024&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Vertical+profiles+of+H2O%2C+H2SO4%2C+and+sulfuric+acid+concentration+at+45%E2%80%9375km+on+Venus&rft.issn=00191035&rft.date=2015&rft.volume=252&rft.issue=&rft.spage=327&rft.epage=333&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103515000408&rft.au=Krasnopolsky%2C+V.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Krasnopolsky, V. (2015). Vertical profiles of H<sub>2</sub>O, H<sub>2</sub>SO<sub>4</sub>, and sulfuric acid concentration at 45–75km on Venus <span style="font-style: italic;">Icarus, 252</span>, 327-333 DOI: <a rev="review" href="http://dx.doi.org/10.1016/j.icarus.2015.01.024">10.1016/j.icarus.2015.01.024</a></span></blockquote>
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Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-35099849668964135592015-07-20T08:05:00.000-07:002015-07-20T08:05:45.218-07:00Quick Look: Touchdown on Venus: Analytic Wind Models and a Heuristic Approach to Estimating Landing Dispersions<p>I'm working through a lot of recent Venus-related papers, so here's another morsel for you that I will not have time to read in depth (I'm prioritizing articles relating to the Venusian surface). The author created a straightforward model of winds on Venus (using data from the VEGA Balloons and the Pioneer descent probes) to determine entry and descent dispersions for future Venus landers.
</p>
From the April 2015 edition of <i>Planetary and Space Science</i>:<br />
<br />
<h4>
Title:</h4>
<blockquote class="tr_bq">
<a href="http://www.sciencedirect.com/science/article/pii/S0032063315000045">Touchdown on Venus: Analytic wind models and a heuristic approach to estimating landing dispersions</a></blockquote>
<h4>
Abstract:</h4>
<blockquote class="tr_bq">
The ‘landing ellipse’ or region of uncertainty within which an unguided probe to Venus may be expected to land is calculated. The region can be usefully seen as the convolution of three different factors: an initial circular delivery uncertainty which is smeared at a grazing entry angle onto the planetary sphere, an along-track uncertainty due to atmospheric density and vehicle aerodynamic variations during hypersonic entry, and a descent dispersion due to uncertain and/or variable zonal and meridional winds. This decomposition allows the various contributions to be instructively exposed and conveniently traded-off, without conducting explicit entry and descent dynamics simulations. It is seen that for descent durations and delivery errors typical of past Venus missions, the zonal wind contribution (determined with an analytic fit to Pioneer Venus tracking data) generally dominates, causing a ~200 km E–W (99%) dispersion, with meridional dispersions being about 4 times smaller. However, when entry angles become shallower than about 8°, the along-track dispersions may dominate, with the resulting ellipse becoming longer or wider depending on the entry azimuth. The analytic wind descriptions presented here may be applied to scientific problems, such as the dispersal of volcanic plumes or impact ejecta.</blockquote>
<h4>
Full Citation:</h4>
<blockquote><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Planetary+and+Space+Science&rft_id=info%3Adoi%2F10.1016%2Fj.pss.2015.01.003&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Touchdown+on+Venus%3A+Analytic+wind+models+and+a+heuristic+approach+to+estimating+landing+dispersions&rft.issn=00320633&rft.date=2015&rft.volume=108&rft.issue=&rft.spage=66&rft.epage=72&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0032063315000045&rft.au=Lorenz%2C+R.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Lorenz, R. (2015). Touchdown on Venus: Analytic wind models and a heuristic approach to estimating landing dispersions <span style="font-style: italic;">Planetary and Space Science, 108</span>, 66-72 DOI: <a rev="review" href="http://dx.doi.org/10.1016/j.pss.2015.01.003">10.1016/j.pss.2015.01.003</a></span></blockquote>
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Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-15294959368025384072015-07-09T22:23:00.001-07:002015-08-05T22:53:55.958-07:00Quick Look: Computer model shows imaging of Venus surface possible from balloonFrom the April 2015 edition of <i>Solar System Research</i>:<br />
<br />
<h4>
Title:</h4>
<blockquote class="tr_bq">
<a href="http://link.springer.com/article/10.1134%2FS003809461502001X">Resolving the surface details on Venus in the balloon- or lander-borne images with a computer modeling method</a></blockquote>
<h4>
Abstract:</h4>
<blockquote class="tr_bq">
Due to the presence of opaque clouds at high altitudes, it is difficult to survey the surface of Venus in the optical spectral range. At the same time, in the under-cloud layer, there are transparency windows at the wavelengths λ = 1.08, 0.85, and 0.65 μm. At these wavelengths, the gaseous absorption (in the whole atmosphere rather than only in the under-cloud layer) is weaker, and the atmospheric transparency is mainly determined by the scattering on molecules. The paper presents the results of the Monte-Carlo computer modeling of the imaging of the surface from a balloon or a lander. It has been shown that the imaging from the lower boundary of the clouds is possible.</blockquote>
<h4>
Full Citation:</h4>
<blockquote class="tr_bq">
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS003809461502001X&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Resolving+the+surface+details+on+Venus+in+the+balloon-+or+lander-borne+images+with+a+computer+modeling+method&rft.issn=0038-0946&rft.date=2015&rft.volume=49&rft.issue=2&rft.spage=110&rft.epage=113&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS003809461502001X&rft.au=Ekonomov%2C+A.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Ekonomov, A. (2015). Resolving the surface details on Venus in the balloon- or lander-borne images with a computer modeling method <span style="font-style: italic;">Solar System Research, 49</span> (2), 110-113 DOI: <a href="http://dx.doi.org/10.1134/S003809461502001X" rev="review">10.1134/S003809461502001X</a></span></blockquote>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-61423907556553960202015-07-08T22:22:00.001-07:002015-07-09T13:48:12.807-07:00Impact Crater Ejecta Mantling on Venusian Tesserae? Earth-based Radar Seems to Say Yes<br />
<h4>
Overview</h4>
The Smithsonian's Bruce Campbell and his colleagues (<a href="http://www.geo.umass.edu/courses/geo892/Campbell%20et%20al,%202015%20Crater%20ejecta%20on%20Venus.pdf">Campbell et al., 2015</a>) combined radar imagery captured in 1988 and 2012 by the Arecibo and Greenbank radio telescopes to better detect the parabola-shaped deposits of impact crater ejecta on Venus. They were looking for such deposits on the highly-deformed terrain of tessera regions, which are suspected of having formed at a time when there was still water on the surface.<br />
Previous researchers had identified large parabolic deposits of radar-dark material extending to the west of many impact craters on Venus. Once launched into the air, the strong winds can transport the ejecta as far as 2000km from the impact site, with the fine-grained material presenting as darker on radar than the surrounding terrain. What had not been conclusively observed was mantling by such deposits on tessera.
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-YSzEoVynx-YS1wow1BUaV-Jag_M6uHEqEdo8TFFx_fLO40SLvcyC-O26UIJl42okbW6sbzW7xh-yhKVRtxakZd61om2SP9q6IZa5JHRAbv-grm66uTS8S0MzX0LjX5OxV2e3Ypw8C-XJ/s1600/stuart_crater.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-YSzEoVynx-YS1wow1BUaV-Jag_M6uHEqEdo8TFFx_fLO40SLvcyC-O26UIJl42okbW6sbzW7xh-yhKVRtxakZd61om2SP9q6IZa5JHRAbv-grm66uTS8S0MzX0LjX5OxV2e3Ypw8C-XJ/s400/stuart_crater.jpg" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Top: Magellan image of Stuart crater parabola<br />
Bottom: Same area imaged by Earth radar</td></tr>
</tbody></table>
By combining the Earth-based radar maps from multiple observations, Campbell et al. achieved 1-2km spatial resolution. They also achieved greater sensitivity to small changes in backscatter using Same-sense Circular (SC) polarization of the transmitted radar signal.
<br /><br />
<h4>
What Did They Find?</h4>
Examining combined images of the area around the tessera region of Alpha Regio, the authors focused on a previously-identified (and fairly obvious) ejecta parabola extending to the West from Stuart crater. In an image compiled from Magellan radar data, the darker material seems to stop at the edge of the tessera terrain. In the SC-polarization image captured by Earth-based telescopes, the increased sensitivity seems to reveal a mantling of a good deal of Alpha Regio by fine-grained material that continues the parabolic shape further westward.
<br />
Other researchers had hypothesized that the dark parabolas and halos of ejecta around some craters (but not all) might be useful as a coarse dating method for impact craters, but Campbell et al. suspect varying conditions during the deposition of ejecta and during subsequent erosion may undermine the creation of a model for dating craters.
<br />
<br />
<h4>
Why Is It Important?</h4>
Tesserae are areas of high interest for future lander missions to Venus, and better characterization of the surface composition will aid in the selection of landing sites.
<br /><br />
<h4>
References:</h4>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2014.11.025&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Evidence+for+crater+ejecta+on+Venus+tessera+terrain+from+Earth-based+radar+images&rft.issn=00191035&rft.date=2015&rft.volume=250&rft.issue=&rft.spage=123&rft.epage=130&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS001910351400654X&rft.au=Campbell%2C+B.&rft.au=Campbell%2C+D.&rft.au=Morgan%2C+G.&rft.au=Carter%2C+L.&rft.au=Nolan%2C+M.&rft.au=Chandler%2C+J.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Campbell, B., Campbell, D., Morgan, G., Carter, L., Nolan, M., & Chandler, J. (2015). Evidence for crater ejecta on Venus tessera terrain from Earth-based radar images <span style="font-style: italic;">Icarus, 250</span>, 123-130 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2014.11.025" rev="review">10.1016/j.icarus.2014.11.025</a></span>
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</div>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-739738383088097732014-01-19T14:31:00.003-07:002015-08-05T22:51:34.382-07:00Call for Papers: Special Venus Issue of Planetary and Space Sciencevia the <a href="http://planetarynews.org/">Planetary Exploration Newsletter</a>:<div>
<br />
<blockquote>
Dear Colleagues, </blockquote>
<blockquote>
We invite submissions of papers related to Venus science and exploration for a Special Issue of Planetary and Space Science. We particularly solicit papers arising from the International Venus Conference held in Catania in June 2013, but further papers not presented at that conference are very welcome. </blockquote>
<blockquote>
Submission for this journal is via:<br /><a href="http://ees.elsevier.com/pss/default.asp" style="color: #1155cc;" target="_blank">http://ees.elsevier.com/pss/<wbr></wbr>default.asp</a> </blockquote>
<blockquote>
<br />To ensure that all manuscripts are correctly identified for inclusion into the special issue, please select "SI: Exploration of Venus" when you reach the "Article Type" step in the submission process. </blockquote>
<blockquote>
Deadline for submission for this Special Issue will be <span class="aBn" data-term="goog_115871367" style="border-bottom-color: rgb(204, 204, 204); border-bottom-style: dashed; border-bottom-width: 1px; position: relative; top: -2px; z-index: 0;" tabindex="0"><span class="aQJ" style="position: relative; top: 2px; z-index: -1;">28 February </span></span>2014, but of course we welcome earlier submissions! </blockquote>
<blockquote>
Please feel free to distribute this announcement widely. </blockquote>
<blockquote>
Guest editors: Hakan Svedhem, Colin Wilson, Giuseppe Piccioni</blockquote>
</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-43640704895442413092013-07-17T07:36:00.000-07:002015-08-05T22:51:17.484-07:00Could there be life in the clouds of Venus?<i>[note: this post is an excerpt from a literature review paper on Venusian Astrobiology that I wrote last year.]</i><br />
<br />
<h2>
3. Extant Life in the Clouds</h2>
<div class="MsoNormalCxSpFirst" style="line-height: 200%; text-indent: .25in;">
Data returned by Mariner II in 1962 drastically changed the picture of conditions on Venus, causing most to lose interest in it as a harbor for life. Nevertheless, within just a few years scientists were speculating that life
might still survive on Venus in the clouds.
Harold Morowitz and Carl Sagan (1967) published a brief article in
Nature containing a great deal of speculation about the nature of a life form
they imagined could survive in such an environment: an organism constructed as
a float bladder filled with molecular hydrogen for buoyancy. This macroorganism would collect water from
rain or by contact with droplets in the clouds, acquire nutrients from minerals
picked up from the surface by the powerful winds, and produce its own lifting
gas as a by-product of photosynthesis.
Given what they knew at the time, they claimed such life in the Venus clouds “can be envisaged which operates entirely on
known terrestrial principles.”<o:p></o:p></div>
<div class="MsoNormalCxSpMiddle" style="line-height: 200%; text-indent: .25in;">
<br />
More realistic hypotheses involving cloud-borne
microorganisms have followed that are compatible with our current knowledge of
the Venusian atmosphere. These
hypotheses should be taken seriously in light of bacteria found actively
growing and reproducing—at temperatures below 0<b>° </b>C—in cloud droplets collected at high altitude on Earth (Sattler et
al. 2001).<o:p></o:p></div>
<div class="MsoNormalCxSpLast" style="line-height: 200%; text-indent: .25in;">
<br /></div>
<h3>
<b><span style="line-height: normal;">3.1</span><span style="font-size: 7pt; line-height: normal;"> </span><!--[endif]-->Conditions in the
Clouds</b></h3>
<div class="MsoListParagraph" style="line-height: 200%; mso-list: l0 level3 lfo1; text-indent: -.5in;">
<o:p></o:p></div>
<div class="MsoNormalCxSpFirst" style="line-height: 200%; text-indent: .25in;">
Venus may be a terribly inhospitable place on or near its
surface, but the conditions at altitudes between 50 and 60 km are remarkably
Earth-like. The pressure is close to 1
bar, the temperature is in a range where water is liquid (0-100<b>° </b>C), there is abundant solar energy,
and the atmosphere contains the primary materials required for life: carbon,
oxygen, nitrogen, and hydrogen (Landis 2003).
Also present: sulfur, phosphorus, chlorine, fluorine, and iron
(Grinspoon and Bullock 2007).<o:p></o:p></div>
<div class="MsoNormalCxSpLast" style="line-height: 200%; text-indent: .25in;">
<br /></div>
<h4>
3.1.1<span style="font-size: 7pt; line-height: normal;">
</span><!--[endif]-->Attributes that Favor
Life</h4>
<div class="MsoListParagraph" style="line-height: 200%; mso-list: l0 level4 lfo1; text-indent: -.5in;">
<o:p></o:p></div>
<div class="MsoNormal" style="line-height: 200%; text-indent: .25in;">
In addition to the general conditions above, the following
attributes are favorable for supporting life in the clouds:<o:p></o:p></div>
<div class="MsoListParagraphCxSpFirst" style="line-height: 200%; mso-list: l1 level1 lfo2; text-indent: -.25in;">
</div>
<ul>
<li><b style="line-height: 200%; text-indent: -0.25in;">Aqueous environment</b><span style="line-height: 200%; text-indent: -0.25in;">: It is certainly not abundant, but water vapor
concentrations approach a few hundred parts per million in the cloud layers
(Ingersoll 2007)</span></li>
<li><b style="line-height: 200%; text-indent: -0.25in;">Continuous clouds</b><span style="line-height: 200%; text-indent: -0.25in;">: the
clouds on Venus are much larger, more continuous, and more stable than those of
Earth, which provides an ongoing habitat for microorganisms (Schulze-Makuch et
al. 2004).</span></li>
<li><b style="line-height: 200%; text-indent: -0.25in;">Superrotation</b><span style="line-height: 200%; text-indent: -0.25in;">: The
clouds of Venus make a complete rotation about the planet once every 4-6 days
(van den Berg et al. 2006), providing a day-night cycle for life in the clouds
that is much shorter than the 117-day cycle experienced at the planet’s surface
(Ingersoll 2007). This enhances the
potential for photosynthetic reactions by reducing the duration of “night”
(Grinspoon and Bullock 2007).</span></li>
<li><b style="line-height: 200%; text-indent: -0.25in;">Atmosphere in disequilibrium</b><span style="line-height: 200%; text-indent: -0.25in;">: O</span><sub style="line-height: 200%; text-indent: -0.25in;">2</sub><span style="line-height: 200%; text-indent: -0.25in;">,
H</span><sub style="line-height: 200%; text-indent: -0.25in;">2</sub><span style="line-height: 200%; text-indent: -0.25in;">, H</span><sub style="line-height: 200%; text-indent: -0.25in;">2</sub><span style="line-height: 200%; text-indent: -0.25in;">S, and SO</span><sub style="line-height: 200%; text-indent: -0.25in;">2</sub><span style="line-height: 200%; text-indent: -0.25in;"> coexist, providing the basis
for energy-yielding redox reactions that could be harvested by microbial life (Schulze-Makuch
and Irwin 2002)</span></li>
</ul>
<br />
<h4>
3.1.2<span style="font-size: 7pt; line-height: normal;"> </span><!--[endif]-->Challenges for cloud-hosted life</h4>
<div class="MsoListParagraphCxSpLast" style="line-height: 200%; mso-list: l0 level4 lfo1; text-indent: -.5in;">
<o:p></o:p></div>
<div class="MsoNormalCxSpFirst" style="line-height: 200%; text-indent: .25in;">
Ultraviolet (UV) radiation from the Sun presents a
challenge for life in the clouds of Venus.
UV is damaging to biological macromolecules, and any surviving organisms
must adapt to it in some fashion. Using
Earth-based organisms for reference, several examples are available: there are
organisms that use pigments such carotenoids and scytonemin for protection,
others grow beneath the safety of soil or water, and some make a shield from
organic compounds derived from dead cells.
A more elaborate example are microbes such as cyanobacteria that possess
internal mechanisms for repairing DNA and resynthesize UV-sensitive proteins
(Schulze-Makuch et al. 2004). Charles
Cockell (1999) points out that the UV flux in the upper clouds of Venus is
comparable to the surface flux on the Archean Earth, the time when life is
believed to have appeared.<o:p></o:p></div>
<div class="MsoNormalCxSpLast" style="line-height: 200%; text-indent: .25in;">
The acidity of the clouds of Venus (pH=0) has been raised
as a possible obstacle to life (Cockell 1999).
Nevertheless, acidophile organisms have been found on Earth, such as <i>Ferroplasma acidarmanus</i> which thrives at
pH 0 (Schulze-Makuch et al. 2004), Picrophilus
oshimae, which showed optimal growth at pH 0.7, but still grew at pH 0
(Schleper et al. 1995), and the green alga Dunaliella acidophila which can
survive at Ph 0, but prefers pH 1 for maximum growth (Grinspoon and Bullock
2007).<o:p></o:p></div>
<div class="MsoListParagraphCxSpFirst" style="line-height: 200%; margin-left: .75in; mso-add-space: auto;">
<br /></div>
<h3>
3.2<span style="font-size: 7pt; line-height: normal;">
</span><!--[endif]-->Speculations on
potential life forms</h3>
<div class="MsoListParagraphCxSpLast" style="line-height: 200%; mso-list: l0 level3 lfo1; text-indent: -.5in;">
<o:p></o:p></div>
<div class="MsoNormalCxSpFirst" style="line-height: 200%; margin-bottom: 12.0pt; mso-add-space: auto; mso-layout-grid-align: none; mso-pagination: none; text-autospace: none; text-indent: .25in;">
Venus researchers have
proposed feasible forms that life might take to survive in the clouds. Wickramasinghe and Wickramasinghe (2008)
suggest that hydrogenogens, a group of terrestrial bacteria and archaea that
can grow anaerobically using CO as their sole carbon source, are good analogs
for cloud-borne organisms on Venus. They
note that the lightning present on Venus (mentioned in section 2.3) could generate
large amounts of CO from the predominantly CO<sub>2</sub> atmosphere. They imagine a scenario occurring within the
three cloud layers of Venus where “(a) bacteria nucleate droplets containing
water and nutrients, (b) colonies grow within the droplets, (c) droplets fall
into regions of higher temperature where they evaporate releasing spores to
convect upwards to yield further nucleation.”<o:p></o:p></div>
<div class="MsoNormalCxSpLast" style="line-height: 200%; text-indent: .25in;">
Dirk Schulze-Makuch, David Grinspoon, and
colleagues (2004) propose that microbial life forms, in response to the high
doses of ultraviolet radiation received in the upper atmosphere, could shroud
themselves in elemental sulfur, possibly a layer of cycloocta-sulfer (S<sub>8</sub>). It is a strong UV absorber, and Venusian organisms
could produce elemental sulfur via a simple photochemical reaction combining H<sub>2</sub>S and CO,
just as some organisms on Earth do.
</div>
<div class="MsoNormalCxSpLast" style="line-height: 200%; text-indent: .25in;">
In another paper co-authored by Schulze-Makuch
and Louis Irwin (2006), they proposed phototrophic organisms in the Venusian
atmosphere that could employ a photosystem based on the oxidation of sulfur, as
many terrestrial organisms thriving in warm seas and hot springs do.<o:p></o:p>
<br />
<div class="MsoNormalCxSpLast" style="line-height: 200%; margin-bottom: 12.0pt; mso-add-space: auto; mso-layout-grid-align: none; mso-pagination: none; text-autospace: none; text-indent: .25in;">
<br /></div><h3>
3.3<span style="font-size: 7pt; line-height: normal;">
</span><!--[endif]-->Possible evidence for
life in the clouds</h3>
<div class="MsoListParagraph" style="line-height: 200%; mso-list: l0 level3 lfo1; text-indent: -.5in;">
<o:p></o:p></div>
<div class="MsoNormalCxSpFirst" style="line-height: 200%; text-indent: .25in;">
Is there any current evidence that could suggest the
existence of cloud-borne organisms on Venus?
There is more than one might think.
Of particular interest are the larger droplets or particles (referred to
as “mode 3” particles) found only in the lowest of Venus’ three cloud layers
(Grinspoon and Bullock 2007). They are
non-spherical (indicative of a solid core), and comparable in size to Earth
bacteria. Their composition is currently
unknown, but they could represent even small bacteria colonies.<o:p></o:p></div>
<div class="MsoNormalCxSpMiddle" style="line-height: 200%; text-indent: .25in;">
The dark regions plainly visible on UV images of Venus are
caused by an unknown UV absorber. The
Venus Monitoring Camera aboard the Venus Express spacecraft took wide-angle
images at the characteristic wavelength of the UV absorber, and determined that
the brightness variation is the result of compositional differences, not
elevation differences (Titov et al. 2008).
Elemental sulfur in the form S8 is a strong UV absorber, and could be
the cause of the dark regions. It has
been proposed that the potential S8 in the Venusian clouds could be a byproduct
of microbiological processes (Schulze-Makuch and Irwin 2006).<o:p></o:p></div>
<br />
<div class="MsoNormalCxSpMiddle" style="line-height: 200%; text-indent: .25in;">
Compounds positively identified in the Venusian atmosphere
could also indicate the presence of organisms.
The presence of oxygenated gases such as O2 and SO2, observed at the
same time with reduced gases such as H2S and H2, indicates the atmosphere is in
a state of disequilibrium. Some active
process is working to maintain this situation, and it may be biological (Landis
2003). The second-most common sulfur gas
in the Venusian atmosphere, Carbonyl
sulfide (COS), is considered a possible indicator for life since its sources on
Earth are almost entirely biological (Landis 2003; Schulze-Makuch and Irwin
2002).<o:p></o:p></div>
<div class="MsoNormalCxSpMiddle" style="line-height: 200%; text-indent: .25in;">
<br /></div>
<div class="MsoNormalCxSpMiddle" style="line-height: 200%; text-indent: .25in;">
<br /></div>
<b>References:
</b><br />
<br />
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Cockell, C. S. (1999). Life on venus.<i> Planetary and Space Science, 47</i>(12),
1487-1501. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Grinspoon, D. H., & Bullock, M. A. (2007). Astrobiology and venus
exploration.<i> Exploring Venus as a Terrestrial Planet, </i>(176), 191. </div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Ingersoll, A. P. (2007). Venus: Express dispatches.<i> Nature, 450</i>(7170),
617-618. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Landis, G. A. (2003). Astrobiology-the case for venus.<i> Journal of the
British Interplanetary Society, 56</i>, 250-254. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Morowitz, H. (1967). Life in the clouds of venus?<i> Nature, 215</i>,
1259-1260. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Sattler, B., Puxbaum, H., & Psenner, R. (2001). Bacterial growth in
supercooled cloud droplets.<i> Geophysical Research Letters, 28</i>(2),
239-242. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Schleper, C., Puehler, G., Holz, I., Gambacorta, A., Janekovic, D.,
Santarius, U., . . . Zillig, W. (1995). Picrophilus gen. nov., fam. nov.: A
novel aerobic, heterotrophic, thermoacidophilic genus and family comprising
archaea capable of growth around pH 0.<i> Journal of Bacteriology, 177</i>(24),
7050-7059. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Astrobiology&rft_id=info%3Apmid%2F15104900&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=A+sulfur-based+survival+strategy+for+putative+phototrophic+life+in+the+venusian+atmosphere.&rft.issn=1531-1074&rft.date=2004&rft.volume=4&rft.issue=1&rft.spage=11&rft.epage=8&rft.artnum=&rft.au=Schulze-Makuch+D&rft.au=Grinspoon+DH&rft.au=Abbas+O&rft.au=Irwin+LN&rft.au=Bullock+MA&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Schulze-Makuch D, Grinspoon DH, Abbas O, Irwin LN, & Bullock MA (2004). A sulfur-based survival strategy for putative phototrophic life in the venusian atmosphere. <span style="font-style: italic;">Astrobiology, 4</span> (1), 11-8 PMID: <a href="http://www.ncbi.nlm.nih.gov/pubmed/15104900" rev="review">15104900</a></span><o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Schulze-Makuch, D., & Irwin, L. N. (2002). Reassessing the
possibility of life on venus: Proposal for an astrobiology mission.<i>
Astrobiology, 2</i>(2), 197-202. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Schulze-Makuch, D., & Irwin, L. N. (2006). The prospect of alien life
in exotic forms on other worlds.<i> Naturwissenschaften, 93</i>(4), 155-172. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Titov, D. V., Taylor, F. W., Svedhem, H., Ignatiev, N. I., Markiewicz, W.
J., Piccioni, G., & Drossart, P. (2008). Atmospheric structure and dynamics
as the cause of ultraviolet markings in the clouds of venus.<i> Nature, 456</i>(7222),
620-623. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
van den Berg, M., Falkner, P., Atzei, A., Phipps, A., Underwood, J.,
Lingard, J., . . . Peacock, A. (2006). Venus entry probe technology reference
study.<i> Advances in Space Research, 38</i>(11), 2626-2632. <o:p></o:p></div>
<div style="line-height: 200%; margin-left: 22.5pt; mso-add-space: auto; text-indent: -22.5pt;">
Wickramasinghe, N., & Wickramasinghe, J. (2008). On the possibility
of microbiota transfer from venus to earth.<i> Astrophysics and Space Science,
317</i>(1), 133-137. <o:p></o:p></div>
</div>
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com1tag:blogger.com,1999:blog-8378641707607178011.post-22333335357171680762013-05-04T22:28:00.001-07:002013-05-04T22:28:16.009-07:00Venus has an Ozone Layer, too<br />
An atmospheric study using the SPICAV-UV instrument recently came to my attention where researchers (Montmessin, et al. 2011) used the data archive to identify (for the first time) a layer of ozone in the upper atmosphere of Venus (previously, ozone had only been identified in the atmospheres of Mars and Earth).<br />
<br />
The team analyzed the complete SPICAV dataset, and determined that UV absorption by O<sub>3</sub> was observed during a stellar occultation run on the night side of Venus during orbit #348. They confirmed ozone detection in 28 additional orbits, and isolated the ozone to a discrete layer no more than 10 km thick near a mean altitude of 100km.<br />
<br />
The observed concentrations of 10<sup>7</sup> – 10<sup>8</sup> molecules per cubic centimeter are consistent with expected values if the upper atmosphere were dominated by the same chlorine-catalyzed destruction cycles present in Earth’s stratosphere.<br />
<br />
Even if the same mechanisms are at work in he Venusian atmosphere, the authors state that the observed ozone layer seems too tenuous to filter out UV radiation and provide protection to organisms that could have existed on Venus.<br />
<br />
<h4>
Referenced:</h4>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2011.08.010&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=A+layer+of+ozone+detected+in+the+nightside+upper+atmosphere+of+Venus&rft.issn=00191035&rft.date=2011&rft.volume=216&rft.issue=1&rft.spage=82&rft.epage=85&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103511003277&rft.au=Montmessin%2C+F.&rft.au=Bertaux%2C+J.&rft.au=Lef%C3%A8vre%2C+F.&rft.au=Marcq%2C+E.&rft.au=Belyaev%2C+D.&rft.au=G%C3%A9rard%2C+J.&rft.au=Korablev%2C+O.&rft.au=Fedorova%2C+A.&rft.au=Sarago%2C+V.&rft.au=Vandaele%2C+A.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Montmessin, F., Bertaux, J., Lefèvre, F., Marcq, E., Belyaev, D., Gérard, J., Korablev, O., Fedorova, A., Sarago, V., & Vandaele, A. (2011). A layer of ozone detected in the nightside upper atmosphere of Venus <span style="font-style: italic;">Icarus, 216</span> (1), 82-85 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2011.08.010" rev="review">10.1016/j.icarus.2011.08.010</a></span>
<br />
<br />
<div>
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</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-30253766030870886372013-05-04T16:34:00.003-07:002013-05-04T23:53:09.259-07:00The SPICAV-UV Instrument Aboard Venus Express<br />
<h4>
Introduction</h4>
The European Space Agency’s Venus Express (VEX) is the only active spacecraft mission at the planet Venus. It carries a number of instruments: A magnetometer, a wide-angle CCD camera, a space plasma detector, a Fourier spectrometer, a thermal spectrometer, a radio science package, and a cluster of spectrometers specifically designed to study the Venusian atmosphere: SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus). This package contains three spectrometers, one of which operates in the ultraviolet and is the subject of this article.<br />
<br />
<h4>
The Instrument</h4>
The UV instrument in SPICAV (described in great detail in Bertaux et al. 2007) is a refurbished flight spare from the Mars Express spacecraft. Sensitive to wavelengths from 118 to 320 nm, it was designed to measure different aspects of the atmosphere in different modes. In nadir orientation, SPICAV-UV measures SO2 and the distribution of the mysterious UV absorber in the clouds. On the night side, it observes the γ and δ bands of NO, and it can measure vertical profiles of CO2, SO2, clouds, and aerosols in stellar occultation mode.<br />
<br />
The UV spectrometer collects light with a 40 mm off-axis parabolic mirror that reflects light toward the spectrometer entrance. There is a configurable slit mechanism in the focal plane that, when left in place, is used for extended source viewing. The slit can be removed from the focal plane entirely for stellar occultation observations. A concave UV grating causes the spectrum to fall onto an image intensifier that is blind to wavelengths greater than 320 nm. The image created on the phosphor output screen of the intensifier is transferred to a 288x384 pixel CCD which can optionally be cooled to 270K using a Peltier cooling unit to reduce dark current. The focal length of the telescope (120mm) results in each CCD pixel having a FOV of 0.01 x 0.01°.<br />
<br />
The slit of the spectrometer is divided into two parts with different widths to allow differing spectral resolutions during observing of an extended source. The narrow part of the slit is 50 μm wide, giving resolving power between 120 and 300 with lower flux, while the wider part (500 μm) provides more sensitivity at the expense of a lower resolving power of ≈20.<br />
<br />
<h4>
Public Datasets</h4>
SPICAV-UV data (in fact, all ESA data more than six months old) are available to the public as part of the ESA Planetary Science Archive (PSA), and are found at http://www.rssd.esa.int/index.php?project=PSA&page=vex. NASA’s Planetary Data System (PDS) standard was adopted by the PSA as a baseline for defining the structure and format of datasets. The PSA allows members of the public to browse the entire available archive via an FTP (File Transfer Protocol) interface, and also provides a Java-based Advanced Search Interface tool that lets a user specify dozens of search parameters, select datasets from search results, and it then “delivers” the requested datasets to a special folder on their server and sends the user an email containing a hypertext link to the data.<br />
<br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUceFi4ozqJYNQyR_fwq2tzFcpJ-p7TWYacmS7Q2Fp0W8VDZny2LTK_GiGP56pejZ2Otlz9PSFSvuvKtERlXlKfxOrzTITjdunabBNhSbEbes6RCpxUr3VlMWHBzDQMTiVuShURAEPHdqm/s1600/SPIV_0AU_0520A01_A_04_QL.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUceFi4ozqJYNQyR_fwq2tzFcpJ-p7TWYacmS7Q2Fp0W8VDZny2LTK_GiGP56pejZ2Otlz9PSFSvuvKtERlXlKfxOrzTITjdunabBNhSbEbes6RCpxUr3VlMWHBzDQMTiVuShURAEPHdqm/s400/SPIV_0AU_0520A01_A_04_QL.jpg" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Figure 1: Quick look analysis of SPICAV-UV data from VEX orbit 520.</td></tr>
</tbody></table>
<br />
Datasets for the SPICAV instrument cluster are stored by spacecraft orbit number. Each individual dataset comes with human-readable descriptor files that define the format, encoding, and semantic meaning of all data provided. In addition to the spectral data themselves, the dataset also include all of the contextual data about the conditions under which the observations were made, such as spacecraft altitude and orientation, instrument temperature, the time and date, exposure times, instrument configuration settings, and many more.<br />
<br />
A SPICAV-UV dataset file includes one or more Collection objects, each containing a header descriptor and data table. A data table consists of five rows of 408 columns, which represents five rows of the CCD with each row containing 408 pixels. Each 16-bit pixel value is a digital representation of the charge collected by that pixel during integration.<br />
<br />
The PSA also provides a data browsing area on the FTP server where summary images of each dataset are available for a “quick look” at the data (see Figure 1).<br />
<br />
<h4>
Science with SPICAV</h4>
One example of an investigation which used data from SPICAV-UV is a recent study hoping to find evidence of extant volcanic activity. Six years of ultraviolet spectrometer data were used to examine the density of sulphur dioxide above the clouds of Venus (Marcq et al. 2012). They found that SO2 column densities increased prior to 2007, and then decreased by a factor of 5 over the next five years. Read the rest of my summary of this research <a href="http://venusdispatches.blogspot.com/2013/01/venus-express-declining-sulphur-dioxide.html">here</a>.<br />
<br />
Another study a year earlier (Montmessin, et al. 2011) used SPICAV-UV data to identify, for the first time, a layer of ozone in the upper atmosphere of Venus (previously, ozone had only been identified in the atmospheres of Mars and Earth). Read more details <a href="http://venusdispatches.blogspot.com/2013/05/venus-has-ozone-layer-too.html">here</a>.<br />
<br />
<br />
<h4>
References</h4>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Planetary+and+Space+Science&rft_id=info%3Adoi%2F10.1016%2Fj.pss.2007.01.016&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=SPICAV+on+Venus+Express%3A+Three+spectrometers+to+study+the+global+structure+and+composition+of+the+Venus+atmosphere&rft.issn=00320633&rft.date=2007&rft.volume=55&rft.issue=12&rft.spage=1673&rft.epage=1700&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0032063307000074&rft.au=Bertaux%2C+J.&rft.au=Nevejans%2C+D.&rft.au=Korablev%2C+O.&rft.au=Villard%2C+E.&rft.au=Qu%C3%A9merais%2C+E.&rft.au=Neefs%2C+E.&rft.au=Montmessin%2C+F.&rft.au=Leblanc%2C+F.&rft.au=Dubois%2C+J.&rft.au=Dimarellis%2C+E.&rft.au=Hauchecorne%2C+A.&rft.au=Lef%C3%A8vre%2C+F.&rft.au=Rannou%2C+P.&rft.au=Chaufray%2C+J.&rft.au=Cabane%2C+M.&rft.au=Cernogora%2C+G.&rft.au=Souchon%2C+G.&rft.au=Semelin%2C+F.&rft.au=Reberac%2C+A.&rft.au=Van+Ransbeek%2C+E.&rft.au=Berkenbosch%2C+S.&rft.au=Clairquin%2C+R.&rft.au=Muller%2C+C.&rft.au=Forget%2C+F.&rft.au=Hourdin%2C+F.&rft.au=Talagrand%2C+O.&rft.au=Rodin%2C+A.&rft.au=Fedorova%2C+A.&rft.au=Stepanov%2C+A.&rft.au=Vinogradov%2C+I.&rft.au=Kiselev%2C+A.&rft.au=Kalinnikov%2C+Y.&rft.au=Durry%2C+G.&rft.au=Sandel%2C+B.&rft.au=Stern%2C+A.&rft.au=G%C3%A9rard%2C+J.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Bertaux, J., Nevejans, D., Korablev, O., Villard, E., Quémerais, E., Neefs, E., Montmessin, F., Leblanc, F., Dubois, J., Dimarellis, E., Hauchecorne, A., Lefèvre, F., Rannou, P., Chaufray, J., Cabane, M., Cernogora, G., Souchon, G., Semelin, F., Reberac, A., Van Ransbeek, E., Berkenbosch, S., Clairquin, R., Muller, C., Forget, F., Hourdin, F., Talagrand, O., Rodin, A., Fedorova, A., Stepanov, A., Vinogradov, I., Kiselev, A., Kalinnikov, Y., Durry, G., Sandel, B., Stern, A., & Gérard, J. (2007). SPICAV on Venus Express: Three spectrometers to study the global structure and composition of the Venus atmosphere <span style="font-style: italic;">Planetary and Space Science, 55</span> (12), 1673-1700 DOI: <a href="http://dx.doi.org/10.1016/j.pss.2007.01.016" rev="review">10.1016/j.pss.2007.01.016</a></span>
<br />
<br />
Esposito, L. W. (1984). Sulfur dioxide: Episodic injection shows evidence for active venus volcanism. Science (New York, N.Y.), 223(4640), 1072-1074.<br />
<br />
Marcq, E., Bertaux, J. L., Montmessin, F., & Belyaev, D. (2012). Variations of sulphur dioxide at the cloud top of Venus's dynamic atmosphere. Nature geoscience, 6(1), 25-28.<br />
<br />
Montmessin, F., Bertaux, J. L., Lefèvre, F., Marcq, E., Belyaev, D., Gérard, J. C., ... & Vandaele, A. C. (2011). A layer of ozone detected in the nightside upper atmosphere of Venus. Icarus, 216(1), 82-85.<br />
<br />
<div>
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>
</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-17754999217892554002013-04-05T15:11:00.002-07:002013-04-05T15:11:22.341-07:00VEXAG Update at NASA's Planetary Science Subcommittee meetingYesterday and today, NASA's Planetary Science Subcommittee met at NASA Headquarters in Washington D.C. Here is the <a href="http://science.nasa.gov/media/medialibrary/2013/04/03/PSS_April-2013_Agenda_v2.pdf">agenda for the meeting</a>, which was available for remote participants via teleconference.<div>
<br /></div>
<div>
During today's session, Dr. Lori Glaze (current VEXAG chair) presented the <a href="http://www.lpi.usra.edu/vexag/">VEXAG</a> report. She outlined</div>
<div>
<ul>
<li>Recent activities,</li>
<li>Results of the annual VEXAG meeting last November,</li>
<li>VEXAG Endorsements (including my favorite, the use of stratospheric balloon observatories), and</li>
<li>Plans for updating the Goals, Objectives, and Investigations document by the end of the year.</li>
</ul>
<div>
Here is a <a href="http://www.lpi.usra.edu/pss/april2013/presentations/9_Glaze.pdf">link to her presentation</a>.</div>
</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-42729972995327404972013-04-01T07:21:00.000-07:002015-08-05T22:50:33.959-07:00Scorpion-like Life Discovered on Surface of Venus?<span style="font-family: Arial, Helvetica, sans-serif;">In a recent paper published in <a href="http://link.springer.com/article/10.1134/S0038094612010042">Solar System Research (Ksanfomality, 2012)</a>, revered senior statesman of Russian planetary science Leonid Ksanfomality reported the detection of possible life forms on Venus.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
Using modern image enhancement techniques to re-analyze the panoramic images captured by Veneras 9 and 13 (in 1975 and 1982, respectively), Ksanfomality discovered objects that he observed moving, <table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgN4GInyEgt_V3WQ7mROPRbUejf8tLMPSVauS4I0-hystTopczVHAb4rNOFPvPP0t4mdO9gVULVsr4ul6rFFYem6O1phG5LwAj_ejKA6sbxWErB8Od94XDLbhNnhsXHTqW6lAq_-_nNVkHc/s1600/Scorpion.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgN4GInyEgt_V3WQ7mROPRbUejf8tLMPSVauS4I0-hystTopczVHAb4rNOFPvPP0t4mdO9gVULVsr4ul6rFFYem6O1phG5LwAj_ejKA6sbxWErB8Od94XDLbhNnhsXHTqW6lAq_-_nNVkHc/s320/Scorpion.jpg" width="264" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">"Scorpion" appeared in image V-13-1-6 BW at the<br />
90th minute after landing of Venera 13. It is absent in<br />
subsequent images.</td></tr>
</tbody></table>
changing shape, and disappearing from view of the cameras (the most interesting one he labeled as the "Scorpion"). He speculated that these indigenous fauna were disturbed from their hiding places in the soil when the spacecraft touched down, and made their way back to safety.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br />
A number of scientists responded to this report in the same issue, heaping equal doses of skepticism and respect on the senior scientist and his work. They conclude that the objects identified are abiotic, and that any apparent movement was the result of image processing artifacts and/or changing shadows cast by clouds.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">Even though this is a false alarm for current life on Venus, the jury is still out on whether life may still exist below the surface, or in the thick cloud cover. More to come. Happy April 1st!</span><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS0038094612010042&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus+as+a+natural+laboratory+for+search+of+life+in+high+temperature+conditions%3A+Events+on+the+planet+on+March+1%2C+1982&rft.issn=0038-0946&rft.date=2012&rft.volume=46&rft.issue=1&rft.spage=41&rft.epage=53&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS0038094612010042&rft.au=Ksanfomality%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics"><br /></span>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS0038094612010042&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus+as+a+natural+laboratory+for+search+of+life+in+high+temperature+conditions%3A+Events+on+the+planet+on+March+1%2C+1982&rft.issn=0038-0946&rft.date=2012&rft.volume=46&rft.issue=1&rft.spage=41&rft.epage=53&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS0038094612010042&rft.au=Ksanfomality%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics"><br /></span>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS0038094612010042&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus+as+a+natural+laboratory+for+search+of+life+in+high+temperature+conditions%3A+Events+on+the+planet+on+March+1%2C+1982&rft.issn=0038-0946&rft.date=2012&rft.volume=46&rft.issue=1&rft.spage=41&rft.epage=53&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS0038094612010042&rft.au=Ksanfomality%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">REFERENCES:</span><br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS0038094612010042&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus+as+a+natural+laboratory+for+search+of+life+in+high+temperature+conditions%3A+Events+on+the+planet+on+March+1%2C+1982&rft.issn=0038-0946&rft.date=2012&rft.volume=46&rft.issue=1&rft.spage=41&rft.epage=53&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS0038094612010042&rft.au=Ksanfomality%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics"><br /></span>
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Solar+System+Research&rft_id=info%3Adoi%2F10.1134%2FS0038094612010042&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Venus+as+a+natural+laboratory+for+search+of+life+in+high+temperature+conditions%3A+Events+on+the+planet+on+March+1%2C+1982&rft.issn=0038-0946&rft.date=2012&rft.volume=46&rft.issue=1&rft.spage=41&rft.epage=53&rft.artnum=http%3A%2F%2Flink.springer.com%2F10.1134%2FS0038094612010042&rft.au=Ksanfomality%2C+L.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Ksanfomality, L. (2012). Venus as a natural laboratory for search of life in high temperature conditions: Events on the planet on March 1, 1982 <span style="font-style: italic;">Solar System Research, 46</span> (1), 41-53 DOI: <a href="http://dx.doi.org/10.1134/S0038094612010042" rev="review">10.1134/S0038094612010042</a></span><br />
<br />
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org/"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border: 0;" /></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-2314287159399377242013-03-15T07:30:00.000-07:002013-03-15T10:09:45.401-07:00Attending LPSC 2013Just a quick note to announce that I am now planning to attend the first three days of the <a href="http://www.lpi.usra.edu/meetings/lpsc2013/">LPSC</a>. There are several people from my university (<a href="http://space.edu/">UND</a>) attending, and I hope to take in as many oral presentations and posters on Venus as I can.<br />
<br />
I've heard that WiFi will not be available and that cell service is spotty, but I'll do my best to blog a bit, and tweet at <a href="http://twitter.com/VenusDispatches">@VenusDispatches</a>.<br />
<br />
If you are not attending but want to be a part of things, some of the big events are being broadcast on <a href="http://www.livestream.com/lpsc2013">Livestream</a>:<br />
<br />
<ul>
<li>Curiosity Rover Science Team Press Briefing (Monday, 3/18 12:00 noon CDT</li>
<li>Plenary Session Featuring Masursky Lecture by Dr. Elkins-Tanton (Monday, 1:30pm CDT)</li>
<li>NASA Headquarters Briefing (Monday, 5:30pm CDT</li>
<li>GRAIL/LRO Press Briefing (Tuesday, 12:00 noon CDT)</li>
</ul>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-67042215572840723202013-03-03T14:42:00.002-07:002013-03-03T14:42:36.599-07:00New VEXAG Newsletter AvailableThe February 2013 Venus Newsletter from the Venus Exploration Analysis Groups is now available at the VEXAG website. It's only six pages, so don't be intimidated! Read the <a href="http://www.lpi.usra.edu/vexag/newsletters/Feb2013/index.pdf">VEXAG Newsletter #6</a>.Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-39268288946468043742013-02-11T07:24:00.000-07:002015-08-05T22:49:55.027-07:00Venus Game-changing Tech Forum at LPSC<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOvfxEuyh2QCRORxpflS55ez0Td-b9Ok9orB1gaDMMA_h3gH7cpyHH0MFsp4HU3vmDkxwTajJrOds2Env3IBu7tf-8FzPmqSzrvlZd4ed5CHuhyphenhyphenYATe7kq5vRmvHupvd8c9iHBc0lHkiND/s1600/gcd_logo2.png" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" height="77" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOvfxEuyh2QCRORxpflS55ez0Td-b9Ok9orB1gaDMMA_h3gH7cpyHH0MFsp4HU3vmDkxwTajJrOds2Env3IBu7tf-8FzPmqSzrvlZd4ed5CHuhyphenhyphenYATe7kq5vRmvHupvd8c9iHBc0lHkiND/s320/gcd_logo2.png" width="320" /></a></div>
From the <a href="http://planetarynews.org/">PLANETARY EXPLORATION NEWSLETTER</a> Volume 7, Number 6 (February 10, 2013):<br />
<br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">VENUS GAME-CHANGING TECHNOLOGY FORUM AT <a href="http://www.lpi.usra.edu/meetings/lpsc2013/">LPSC </a>- MONDAY, MARCH 18TH, 2013</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">Space technology is a vital tool for both scientists and engineers to reach some of the most extreme environments in our solar system. Exploring Venus with these technologies can answer key questions ranging from the history to the habitability of our universe.</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">To help us understand these challenges and to identify technologies that may assist you in this quest, we need your help! We would like to tell you about Space Technology and listen to your technology needs through a dialog in a Town Hall meeting format.</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">First, we plan to provide an overview of <a href="http://www.nasa.gov/offices/oct/stp/game_changing_development/index.html">Space Technology and the Game-Changing Development Program</a>, including specific examples of Venus exploration technology projects currently under development.</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">Next, we would like to hear from you! Your identified technology needs play a significant role in our portfolio planning and could enable innovative and exciting future Venus exploration missions.</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">We are looking forward to seeing y'all at LPSC on Monday March 18, from 12:00 to 13:15 in the Panther Creek Room. </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">The forum is hosted by the <a href="http://www.lpi.usra.edu/vexag/">VEXAG</a> and will be run by <a href="http://www.nasa.gov/centers/langley/news/researchernews/snapshot_SGaddis.html">Steve Gaddis</a>, Director of the</span><br />
<span style="font-family: Courier New, Courier, monospace;">Game-Changing Development Program, NASA LaRC.</span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-55776835266036910322013-02-07T06:27:00.000-07:002015-08-05T22:49:28.735-07:00Searching for volcanic eruptions on Venus: Nothing yet<br />
Eugene Shalygin and colleagues report on their ongoing attempts to detect volcanic activity on Venus. The Venus Monitoring Camera (VMC) carried by the Venus Express orbiter is capable of making observations in the near-infrared centered around 1.01 microns, a wavelength at which thermal emissions from the planet's surface can be detected on the night side. They are making observations in likely locations, specifically the area around the Maat Mons, Sapas Mons, and Ozza Mons volcanoes (Messenger spacecraft SAR data showed recent volcanism here, geologically speaking), with the hope of detecting localized bright spots in the images.<br />
<br />
To get an idea of how often Maat Mons might erupt, the team reviewed the eruption history of Mauna Loa on Earth since 1900. They found that even though it is an active volcano, there are only eruption events on 1.6% of the days during the 100 years they evaluated. Accounting for the length of observation on Venus, the authors calculated a probability of seeing an eruption during any particular observation at 8.6%. <br />
<br />
Ultimately, the series of observations made with the VMC, 12 passes in all, did not reveal any suspicious hot spots that could be interpreted as volcanic events. This does not preclude the possibility that eruptions occurred during this time, but did so while Venus Express was not looking.<br />
<br />
They recommend that they keep looking, of course (I concur).<br />
<br />
REFERENCES:<br />
<br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Planetary+and+Space+Science&rft_id=info%3Adoi%2F10.1016%2Fj.pss.2012.08.018&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Search+for+ongoing+volcanic+activity+on+Venus%3A+Case+study+of+Maat+Mons%2C+Sapas+Mons+and+Ozza+Mons+volcanoes&rft.issn=00320633&rft.date=2012&rft.volume=73&rft.issue=1&rft.spage=294&rft.epage=301&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0032063312002553&rft.au=Shalygin%2C+E.&rft.au=Basilevsky%2C+A.&rft.au=Markiewicz%2C+W.&rft.au=Titov%2C+D.&rft.au=Kreslavsky%2C+M.&rft.au=Roatsch%2C+T.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Shalygin, E., Basilevsky, A., Markiewicz, W., Titov, D., Kreslavsky, M., & Roatsch, T. (2012). Search for ongoing volcanic activity on Venus: Case study of Maat Mons, Sapas Mons and Ozza Mons volcanoes <span style="font-style: italic;">Planetary and Space Science, 73</span> (1), 294-301 DOI: <a href="http://dx.doi.org/10.1016/j.pss.2012.08.018" rev="review">10.1016/j.pss.2012.08.018</a></span><br />
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<span style="display: none;">claimtoken-51140758ef0d3</span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-7672551376864153872013-01-29T12:30:00.000-07:002013-01-29T13:31:31.530-07:00Water vapor in the Venus troposphereIn a recent paper, Sarah Chamberlain from the University of Lisbon and her colleagues report on their interpretation of ground-based Venus observations from 2004 using new modeling techniques to determine the amount of water vapor present in the lower atmosphere.<br />
<br />
<table cellpadding="0" cellspacing="0" class="tr-caption-container" style="float: right; margin-left: 1em; text-align: right;"><tbody>
<tr><td style="text-align: center;"><a href="http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Aat.jpg/250px-Aat.jpg" imageanchor="1" style="clear: right; margin-bottom: 1em; margin-left: auto; margin-right: auto;"><img border="0" height="320" src="http://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Aat.jpg/250px-Aat.jpg" width="216" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Anglo-Australian Telescope</td></tr>
</tbody></table>
In spite of the dense clouds and haze, near-infrared windows occur on the Venus nightside where the scattered daylight radiation is minimal, allowing thermal radiation emission from the deep lower atmosphere to be detected. Immediately after the inferior conjunction of Venus in June of 2004, ground-based infrared spectroscopy of the nightside troposphere were obtained at Siding Spring Observatory using the IRIS2 spectrograph on the4-meter Anglo-Australian Telescope.<br />
<br />
The authors took the data from the 2004 observations and fitted them with spectra simulated using VSTAR (Versatile Software for Transfer of Atmospheric Radiation). They find a best fit water vapor abundance of 31 parts per million by volume (-6 + 9 ppmv), which is in
agreement with recent results by Bézard et al. 2011 using the SPICAV instrument aboard the Venus Express spacecraft. This is also consistent with the current consensus that water vapor abundance is approximately 30 ppmv below 30km altitude.<br />
<br />
So why all the attention to water vapor in the troposphere of Venus? Well,<br />
<br />
1. Water vapor is an important chemical reactant in the lower atmosphere as it is the major reservoir of hydrogen, which is hypothesized to buffer or regulate the atmospheric abundances of HCL and HF,<br />
<br />
2. Water vapor is important to the formation of the H<span style="font-size: 8pt; vertical-align: -2pt;">2</span>SO<span style="font-size: 8pt; vertical-align: -2pt;">4 </span> clouds that enshroud the planet, and<br />
<br />
3. combining these with the loss of water vapor over long timescales through oxidation reactions with iron minerals at the surface and through photo-disassociation in the upper atmosphere, studies of the abundance distributions and profiles of water vapor in the lower troposphere help to constrain the chemistry and evolution of the near-surface environment.<br />
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<br />
REFERENCES:<br />
<br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2011.08.025&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=The+1.10-+and+1.18-%CE%BCm+nightside+windows+of+Venus+observed+by+SPICAV-IR+aboard+Venus+Express&rft.issn=00191035&rft.date=2011&rft.volume=216&rft.issue=1&rft.spage=173&rft.epage=183&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103511003423&rft.au=B%C3%A9zard%2C+B.&rft.au=Fedorova%2C+A.&rft.au=Bertaux%2C+J.&rft.au=Rodin%2C+A.&rft.au=Korablev%2C+O.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Bézard, B., Fedorova, A., Bertaux, J., Rodin, A., & Korablev, O. (2011). The 1.10- and 1.18-μm nightside windows of Venus observed by SPICAV-IR aboard Venus Express <span style="font-style: italic;">Icarus, 216</span> (1), 173-183 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2011.08.025" rev="review">10.1016/j.icarus.2011.08.025</a></span><br />
<br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Icarus&rft_id=info%3Adoi%2F10.1016%2Fj.icarus.2012.11.014&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Ground-based+near-infrared+observations+of+water+vapour+in+the+Venus+troposphere&rft.issn=00191035&rft.date=2013&rft.volume=222&rft.issue=1&rft.spage=364&rft.epage=378&rft.artnum=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0019103512004605&rft.au=Chamberlain%2C+S.&rft.au=Bailey%2C+J.&rft.au=Crisp%2C+D.&rft.au=Meadows%2C+V.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Chamberlain, S., Bailey, J., Crisp, D., & Meadows, V. (2013). Ground-based near-infrared observations of water vapour in the Venus troposphere <span style="font-style: italic;">Icarus, 222</span> (1), 364-378 DOI: <a href="http://dx.doi.org/10.1016/j.icarus.2012.11.014" rev="review">10.1016/j.icarus.2012.11.014</a></span><br />
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Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-13985584790891026462013-01-17T08:00:00.000-07:002013-01-17T08:11:26.505-07:00Venus Upper Atmosphere Workshop on January 24th<div class="separator" style="clear: both; text-align: center;">
<a href="http://solarsystem.nasa.gov/multimedia/gallery/V2057_0040_uv2_global_view_05b.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="200" src="http://solarsystem.nasa.gov/multimedia/gallery/V2057_0040_uv2_global_view_05b.jpg" width="196" /></a></div>
<i>UPDATED AGAIN: </i>The <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SP/VenusUpper/agenda.html">agenda</a> has been fleshed out with individual talks and presenters. Geoffrey Landis is scheduled to discuss the use of UAVs!<br />
<i><br /></i>
<i>UPDATED:</i> <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SP/VenusUpper/agenda.html#webex" target="_blank">Details now available for remote attendees</a>.<br />
<br />
Are you a planetary scientist studying the Venusian atmosphere, or an engineer looking to build spacecraft or instrumentation that will further the study of our twin planet? Then clear your calendar on January 24th, 2013.<br />
<br />
NASA's Glenn Research Center, along with the Ohio Aerospace Institute, is sponsoring a Science and Technical Interchange Meeting (STIM) on the topic of <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SP/VenusUpper/workshop.html" target="_blank">Venus Upper Atmosphere Investigations</a>.<br />
<br />
The aim of this day-long set of meetings is to encourage the discussion of shared goals and priorities with regard to the study of the atmosphere of Venus by spacecraft.<br />
<br />
According to the <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SP/VenusUpper/agenda.html" target="_blank">agenda</a>, they hope to<br />
<ol>
<li>Foster a science discussion on goals, objectives, priorities, and significance of the Venus upper atmosphere and how Venus upper atmosphere science would contribute to overall exploration of Venus,</li>
<li>discuss the desired measurements and measurement requirements to achieve potential Venus upper atmosphere science, and </li>
<li>discuss spacecraft concepts and technologies that could reach the Venus UA and collect and return the desired data.</li>
</ol>
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If you cannot attend in person, they may be making arrangements for attending remotely-- I have a question out to one of the organizers and I'll update this post accordingly.</div>
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<a href="http://www.nasa.gov/centers/glenn/images/content/653606main_3by4vessel_226x170.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" src="http://www.nasa.gov/centers/glenn/images/content/653606main_3by4vessel_226x170.jpg" /></a></div>
If you are lucky enough to be able to travel to the workshop and can arrive a day early, they are planning a tour of the nearly-completed NASA <a href="http://www.nasa.gov/centers/glenn/technology/venus_chamber.html" target="_blank">Glenn Extreme Environments Rig</a> (GEER) on the afternoon of the 23rd. Once completed, the GEER will be able to accurately simulate any planetary environment in the solar system, including both the surface and the atmosphere of Venus. Read more about the GRC's Strategic Science work <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SS/" target="_blank">here</a>.<br />
<br />
If you are interested in attending, <a href="http://spaceflightsystems.grc.nasa.gov/SSPO/SP/VenusUpper/register.html" target="_blank">registration is required</a>.</div>
Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-26341209548252691432013-01-14T08:00:00.000-07:002013-01-14T10:56:24.420-07:00Venus Express flew over an electrical storm<br />
Christopher Russell has been looking for proof of lightning in the atmosphere of Venus for quite a while (his earliest publication I could find on the subject was in 1979). Now, Russell and his colleagues report on the strongest evidence yet for Venusian lightning (2012).<br />
<br />
In order to remove interference from magnetometer data collected previously by Venus Express, Russell and his team devised a new algorithm that uses the inboard sensor to detect interfering signals and then removes the same signals from the outboard sensor data, resulting in a "cleaned" signal covering the frequency rane from 0 to 64 Hz.<br />
<br />
Using the improved data collected during periapsis of the Venus Express spacecraft on April 15th of 2007, the researchers detected magnetic signals that led them to believe the craft had flown over an electrical storm.<br />
<br />
Of note are two very different signals the authors believe are associated with electrical activity in the atmosphere of Venus:<br />
<br />
1. a waveform that follows the prevailing magnetic field in the ionosphere and occurs at 20 Hz or above in the Extremely Low Frequency (ELF) range, and<br />
<br />
2. a second signal that occurs at Ultra-low (ULF) frequencies (and are thus not restricted to moving along the magnetic field) and which propagates upward through the atmosphere. The likely source is electrical activity beneath the spacecraft.<br />
<br />
In addition, the data revealed the presence of whistler waves (which would be expected if lightning were present), and are consistent with previous studies (Russell et al. 2007).<br />
<br />
Why is lightning on Venus important? Knowing it is there can help in comparative studies between Earth and Venus, but more importantly it can help assist in the understanding of the chemical processes at work in the Venusian atmosphere. The temperatures and pressures present in a lightning discharge provide a significant amount of energy that can drive chemical reactions, such as those that produce nitrous oxide. Lightning is a proposed energy source for the creation of amino acids on the primordial Earth, the building blocks of life.<br />
<br />
<br />
REFERENCES<br />
<br />
Taylor, W. W. L., Scarf, F. L., Russell, C. T., & Brace, L. H. (1979). Evidence for lightning on venus. <i>Nature</i>, 279, 614-616.<br />
<br />
Russell, C., Zhang, T., Delva, M., Magnes, W., Strangeway, R., & Wei, H. (2007). Lightning on venus inferred from whistler-mode waves in the ionosphere. <i>Nature</i>, 450(7170), 661-662.<br />
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<br />
<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Geophysical+Research+Letters&rft_id=info%3Adoi%2F10.1029%2F2012GL054308&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Electromagnetic+waves+observed+on+a+flight+over+a+Venus+electrical+storm&rft.issn=0094-8276&rft.date=2012&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Fwww.agu.org%2Fpubs%2Fcrossref%2Fpip%2F2012GL054308.shtml&rft.au=Russell%2C+C.&rft.au=Leinweber%2C+H.&rft.au=Zhang%2C+T.&rft.au=Daniels%2C+J.&rft.au=Strangeway%2C+R.&rft.au=Wei%2C+H.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Russell, C., Leinweber, H., Zhang, T., Daniels, J., Strangeway, R., & Wei, H. (2012). Electromagnetic waves observed on a flight over a Venus electrical storm <span style="font-style: italic;">Geophysical Research Letters</span> DOI: <a rev="review" href="http://dx.doi.org/10.1029/2012GL054308">10.1029/2012GL054308</a></span>
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<br />
<span style="float: left; padding: 5px;"><a href="http://www.researchblogging.org"><img alt="ResearchBlogging.org" src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png" style="border:0;"/></a></span>Paul Wrenhttp://www.blogger.com/profile/06609006306944829120noreply@blogger.com0tag:blogger.com,1999:blog-8378641707607178011.post-67267541409814971182013-01-13T15:44:00.000-07:002013-01-13T15:46:00.375-07:00Variations in sulphur dioxide at the cloud tops of Venus: due to volcanoes? maybe notA recent article in Nature Geoscience, <a href="http://www.nature.com/ngeo/journal/v6/n1/full/ngeo1650.html">Variations of sulphur dioxide at the cloud top of Venus's dynamic atmosphere</a>, has caused the science press to get excited about the possibility of active volcanoes on Venus.<br />
<br />
Every news headline I saw over the last few weeks that referred to this article wondered aloud if there are active volcanoes. Even the <a href="http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51185" target="_blank">ESA website</a> poses the news as a question. So, does Venus have active volcanism? First, let's talk about the paper and what it reports.<br />
<br />
Emmanuel Marcq and colleagues used ultraviolet spectrometer data collected from 2007 to 2012 using the SPICAV instrument aboard the Venus Express spacecraft to examine the density of sulphur dioxide above the clouds of Venus. They found that <span style="font-family: Georgia, Times New Roman, serif;">SO<span style="background-color: white; font-size: 10.909090995788574px; line-height: 10.651514053344727px; white-space: nowrap;">2</span></span> column densities increased prior to 2007, and then decreased by a factor of 5 over the next five years.<br />
<br />
This finding is quite similar to observations made by the Pioneer Venus Orbiter in the 1970s and 1980s, which revealed a ten-fold decrease in <span style="font-family: Georgia, Times New Roman, serif;">SO<span style="background-color: white; font-size: 10.909090995788574px; line-height: 10.651514053344727px; white-space: nowrap;">2</span></span> column density. At the time, Larry Esposito (1984) of the Laboratory for Atmospheric and Space Physics in Boulder interpreted this decline to have occurred following an episode of volcanogenic upwelling from the lower atmosphere (it is important to note that <span style="font-family: Georgia, 'Times New Roman', serif;">SO</span><span style="background-color: white; font-family: Georgia, 'Times New Roman', serif; font-size: 10.909090995788574px; line-height: 10.651514053344727px; white-space: nowrap;">2</span> is abundant and ubiquitous in the lower atmosphere of Venus).<br />
<br />
Marcq, et al. conclude that the <span style="font-family: Georgia, 'Times New Roman', serif;">SO</span><span style="background-color: white; font-family: Georgia, 'Times New Roman', serif; font-size: 10.909090995788574px; line-height: 10.651514053344727px; white-space: nowrap;">2</span> variability observed from the 1970s to the present is the result of long-timescale fluctuations in upward transport from the troposphere to the mesosphere.<br />
<br />
What they do not know is whether this is the result of 1) episodic increased buoyancy from volcanic plumes, or 2) intrinsic dynamic variability in the upward component of the global circulation.<br />
<br />
Back to our original question: Does Venus possess active volcanoes? This study cannot answer that question. The authors seem to want it to be so, but say in their conclusion: "By Occam's razor, we are inclined to think that this variability originates from intrinsic dynamical variability in the ascending sub-solar branch of the global circulation at cloud-top level on a decennial timescale rather than from an external forcing such as extra buoyancy caused by volcanic eruptions, but we cannot dismiss a volcanic forcing through our study alone."<br />
<br />
It's pretty clear that most people want active volcanoes on Venus, but the jury is still out, I'm afraid.<br />
<br />
<br />
<br />
REFERENCES:<br />
<br />
<div>
Esposito, L. W. (1984). Sulfur dioxide: Episodic injection shows evidence for active venus volcanism.<i> Science (New York, N.Y.), </i><i>223</i>(4640), 1072-1074. doi: 10.1126/science.223.4640.1072
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<span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.jtitle=Nature+Geoscience&rft_id=info%3Adoi%2F10.1038%2FNGEO1650&rfr_id=info%3Asid%2Fresearchblogging.org&rft.atitle=Variations+of+sulphur+dioxide+at+the+cloud+top+of+Venus%E2%80%99s+dynamic+atmosphere&rft.issn=1752-0894&rft.date=2012&rft.volume=&rft.issue=&rft.spage=&rft.epage=&rft.artnum=http%3A%2F%2Fwww.nature.com%2Fdoifinder%2F10.1038%2Fngeo1650&rft.au=Marcq%2C+E.&rft.au=Bertaux%2C+J.&rft.au=Montmessin%2C+F.&rft.au=Belyaev%2C+D.&rfe_dat=bpr3.included=1;bpr3.tags=Astronomy%2CEarth+and+Planetary+Astrophysics">Marcq, E., Bertaux, J., Montmessin, F., & Belyaev, D. (2012). Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere <span style="font-style: italic;">Nature Geoscience</span> DOI: <a rev="review" href="http://dx.doi.org/10.1038/NGEO1650">10.1038/NGEO1650</a></span></div>
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