Here's a Venus map I put together for my solar system simulator. It needs work, to match the different sources better. This is constructed from Magellan (left, right and stereo passes), Venera and the two published Arecibo maps.

Click to view attachment

The projections are stereographic and mercator. I do spherical image processing in this representation, because it allows pretty conventional operations with just isotropic scaling of the filters for different regions.

Nice, Don. My map is a composite of two datasets - the Magellan altimetry, patched with Pioneer Venus, which is used in USGS's Pigwad system, and the Magellan global mosaic (composite of all three cycles, I think) which is patched in the north with Venera. That was originally off the Photojournal but I have reprojected it. So at the pole there is a bit of Venera imagery, very subdued. I just add the SAR images to give a bit of extra information over the rather bland altimetry image.

Phil

I reprocessed the Magellan altimetry data with the corrected spacecraft ephemeris produced in the 1990s. If you've noticed radial grooves in the data, this will fix that for you. If you're using the raw altimeter samples, that is.

The relief I used, from Pigwad, does have those streaks along orbit tracks. I did a bit of editing - to the image, not the DEM - to remove them. Could still be better though!

Phil

I'm likely reposting this every six months as amnesia overcomes me, but here's a link to a map I put together based on a DEM bump map and SAR for albedo, set to Venera 13/14 colors.

Additionally, I reprojected it onto an ellipse to mimic the great National Geographic map of Mars that had a similar feel.

http://www.cogsci.indiana.edu/farg/rehling.../venus-oval.jpg

Very nice map, JRehling

Phil

Yes, that's a nice projection.

Part V: Astrobiology

Sympathy for the Devil: The Case for Life on Venus

David Grinspoon, Southwest Research Institute, Boulder

33 min.

"Venus favors the bold."

-- Ovid (43 BC - 17 AD)

The next four lectures will ask the question: "Why did things go so right for
life on Earth?" To answer that question, we ask, "Why did things go so badly on
Earth's nearest neighbors, Venus and Mars?"

Mars is half the size of Earth, but Venus is nearly Earth's identical twin. All
three planets likely had substantial oceans, but Venus and Mars lost their
oceans some time ago. Mars' oceans apparently evaporated almost immediately,
but Venus may have kept its oceans for 600 million years, as estimated by Jim
Kasting of Penn State in 1988, or for as long as two billion years, as
suggested by David Grinspoon in this week's lecture.

The Evolutionary Biology Lecture of the Week for June 19, 2006 is now available
at:

http://aics-research.com/lotw/

http://www.newscientistspace.com/article/d...an-thought.html

The colossal outpouring of lava thought to have almost totally resurfaced Venus 500 million years ago never happened, a new study says. If correct, it means that a much longer record of Venus's history is preserved on the planet's surface.

Excellent Ground-Based Venus Images

At http://www.astrode.de/venus07.htm, one can see some excellent 'amatuer' ground-based images of Venus. Text in German.

My understanding is these are taken from a 10th floor location in the center of Munich, using a web cam that takes data over a period of time and then uses an algorithmic selection of the most crisp images, which are then overlayed.

Most excellent.

-don

That is really great stuff -- the best ground-based Venus images I've seen. And Munich seems like an exceptionally poor location to work from compared to the Andes or Arizona.

By comparison, the one Mercury image, while impressive in its own right, is far from the best I've seen, with amateurs like the late Erwin van der Velden having resolved crater ray systems. I wonder if the best practices for imaging Mercury could be adapted to Venus and produce even better work? Of course, there are many factors making the two tasks different -- Venus is intrinsically brighter but only shows this detail in UV or IR. Mercury is less luminous per unit surface area, shows details in visible spectra, but offers very low contrast. And offers much less favorable separation from the Sun.

These Venus images make me wish for a systematic ground-based survery showing "video" of its global weather. Easily done for a tiny fraction the cost of a space-based mission.

WOW!!!



Those are far and away the best ground-based Venus images I've seen; that kind of quality would have been unthinkable even from large observatory telescopes a generation ago.

Ditto for JRehling's movie concept...

Check out these images I came across. Looks almost like a spacecraft image.

http://www.msnbc.msn.com/id/18040861/

New pictures!

I can't find any mention on the ESA mission page. MSNBC may have raided their data and released it for them.

Those are the four that were released a couple weeks ago:
http://www.esa.int/esaSC/SEM9N77DWZE_index_0.html

I've gotten a (very) little more info on these and have been planning to post but haven't managed to get to it yet...

--Emily

Speaking of Venus science, the first of several papers of JGR-Planets - Special Collection: Exploring Venus as a Terrestrial Planet, has been published online.

Venus Ground-Based Images

At ESA's pages for the Venus Amateur Observing Project, more excellent photos of Venus taken from her sister planet are now posted at:

http://tinyurl.com/2xxb2d

These video frame overlays are just fantastic.

Movies of Venus' South Pole Vortex

The ESA science pages have been updated to include an article on the south pole vortex on Venus. Venus Express has imaged the pole over a period of days, and used special downlink arrangements to take much more data than previously allowed. The resulting movies taken by the VIRTIS imaging spectrometer are quite amazing.

The page, entitled "Venus Express’ infrared camera goes filming", is available at:
http://www.esa.int/SPECIALS/Venus_Express/SEMQKVU681F_0.html

More science results can be viewed at:
http://sci.esa.int/science-e/www/object/in...fobjectid=39432

Another set of ground-based images of Venus has now been posted at:
http://sci.esa.int/science-e/www/object/in...fobjectid=41107


And some cute pictures of the recent occultaion of Venus by the Moon can be found at:

http://foto.star-shine.ch/details.php?image_id=630
http://forum.astronomie.de/phpapps/ubbthre...0/page/0#525968
http://www.flickr.com/photos/peter_heinzen/567875780/

http://forum.astronomie.de/phpapps/ubbthre...0/page/0#525967