Show threadPhil StookeNov 19

... but when Magellan images became available they attracted more attention:

https://www.researchgate.net/profile/Vladimir-Gubenko/publication/258780090_Perspectives_of_the_bistatic_radar_and_occultation_studying_of_the_Venus_atmosphere_and_surface/links/53e8b0a60cf21cc29fdc837b/Perspectives-of-the-bistatic-radar-and-occultation-studying-of-the-Venus-atmosphere-and-surface.pdf

https://www.hou.usra.edu/meetings/lpsc2016/pdf/2094.pdf

(similar content, slightly more condensed URL)

If I continued with my Venus atlas project I would certainly have been mapping this stuff, but it's not going to happen.

Tomorrow it's time to move on the Venera 10.
#venus #venera9

Show threadPhil StookeNov 19
When we looked at Soviet lunar missions I showed the Luna 22 bistatic radar image of part of the Moon. It didn't tell us much we didn't know about the Moon (rocky surfaces and slopes facing the radar will reflect it on to the detector). But a year later Venera 9 used bistatic radar to study Venus, an utterly unknown surface, so in a sense the Luna 22 lunar data are like 'ground truth' for Venus. The results were published at the time in a Russian journal...
#venus #venera9
Show threadPhil StookeNov 18
Lastly... that odd object protruding into the foreground is a densitometer dropped onto the surface to estimate its hardness. There is one other interesting Venera 9 dataset to mention... tomorrow.
#venus #venera9
Show threadPhil StookeNov 18
Here's that map with its crudely separated section. But what's this? Why have I rotated it? As far as I can tell there is absolutely no information about the orientation of the map, so here it is in an arbitrary orientation. I suppose a whole-sky image might have revealed the direction of the sun (30 degrees above the horizon), but we don't have one. Shadows don't tell us anything, they are all just under rocks, not to one side. There's a lot we don't know.
#venus #venera9
Show threadPhil StookeNov 18
A small point and a big one about yesterday's map made from the Venera 9 panorama. First, at the left end we see a more distant hillside (or possibly two) beyond a near horizon (or perhaps two). I should have separated the bit beyond the closest horizon to suggest an intervening valley - I'll show it in the next post so you can see what I mean. The bright spot at far left might be a third hillside beyond another valley. It's darker than the sky at the right. Second...
#venus #venera9
Show threadPhil StookeNov 17
I wanted to be able to map the Venera landing sites. We should be able to project the panoramas to a map geometry. I'm not clever enough to figure it out, but veteran space artist Don Davis published drawn maps for Veneras 9 and 10, so I had a start. He didn't map the outer ends of the images so I had to improvise that bit. This image is a first attempt at projecting the Venera 9 pan to a map. It could be improved considerably.
#venus #venera9
Show threadPhil StookeNov 17
I want to make a map of this Venera 9 site. To start, here is a Soviet-era version of the panorama. I do want to emphasize what an incredible advance this was - the first image of the landscape of another planet, taken in October 1975, before the Viking landings on Mars. Nobody else has done this, and the Russians took 6 panoramas at 4 sites. Venus exploration was the greatest achievement of the Soviet planetary program.
#venus #venera9
Show threadPhil StookeNov 16
We are probably looking across a valley at a slope on the other side, and right in the corner is a glimpse of a triangle of light. It's darker than the sky on the right - is it another hillside farther away? We see so little of it and the image is so damaged in that area that we don't really know what we are looking at. But a rough hilly landscape with lots of rocks is pretty much what the radar images from orbit suggest.
#venus #venera9
Show threadPhil StookeNov 16
First impressions: it's very rocky, a landscape of broken chunks of rock, some of them looking rounded (maybe by sandblasting as surface winds blow sediment around). Some look like they may be made of 2 or more layers. Between them is a gravelly surface. At right the horizon has rocks seen in silhouette against the sky - they can't be far away. At left a near horizon with rocks has a fainter landscape beyond it, faintly showing signs of more rocks.
#venus #venera9
Show threadPhil StookeNov 16

This view on Don Mitchell's page shows how the original pan has many gaps (during which other telemetry was transmitted), how some of them can be patched from the second pan, and finally how the remaining gaps can be patched by interpolating. That's to make it look good, it doesn't add any new data. And that end of the pan was very broken up so you have to be careful about interpreting that part of the image.

http://mentallandscape.com/C_Venera09_Processed.jpg

#venus #venera9