Phil Stooke
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Phil Stooke
@philstooke.mastodon.social.ap.brid.gy
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Professor Emeritus, University of Western Ontario. Space exploration and planetary cartography, historical and present. A longtime poster on […]

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philstooke.mastodon.social.ap.brid.gy
The next mission to launch to Venus was NASA's Pioneer Venus mission, with two components. Here is a NASA look back on its 4oth anniversary:

https://www.nasa.gov/centers-and-facilities/ames/40-years-ago-pioneers-encounter-venus/

The mission consisted of an […]

[Original post on mastodon.social]
The Pioneer Venus Orbiter took this image of the clouds of Venus, and many more, to monitor the clouds and atmospheric dynamics. It was scanned by a photopolarimeter on the spinning spacecraft (not a camera, it only measures brightness one pixel at a time, scanning a line as it spins and using motion along its orbit to move to the next line). This was like the imagers on Pioneer 10 and 11 at Jupiter, and similar to the Soviet Luna 19 and 22 images.
November 26, 2025 at 7:38 AM
philstooke.mastodon.social.ap.brid.gy
This all looks very nice, but we still don't know much about what is being seen. Take the very bright area Maxwell at the top - is it a mountain range or a canyon like Juventae Chasma on Mars? We only know it's rough. (Now we know it's a mountain) What about the dark smooth area with a bright […]
Original post on mastodon.social
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November 25, 2025 at 8:06 AM
philstooke.mastodon.social.ap.brid.gy
Around the time of Veneras 9 and 10, Earth-based radar mapping was improving. This map is a composite of two radar datasets from this period, reprojected to the azimuthal projection I always use for global maps.

One paper was this:

Campbell, D.B. and Burns […]

[Original post on mastodon.social]
This radar map of Venus used data from around 1975, cited in the main text. Global images like this made by delay-doppler imaging are north-south ambiguous and the ambiguity can't be resolved around the sub-Earth latitude so there is usually a bland strip. but here it has been filled by an image which was printed with the ambiguous zone intact. Over several years of observing, images with different sub-Earth latitudes can fill that gap, but they always show the same hemisphere of Venus.
November 25, 2025 at 7:59 AM
philstooke.mastodon.social.ap.brid.gy
Here is a rather crudely reprojected version of the Venera 10 panorama. Once again we don't know the orientation of this map. The lander ended up on a patch of flat rocky slabs, and there seem to be similar rocky areas on each horizon, left and right. Between […]

[Original post on mastodon.social]
This image is a roughly reprojected version of the Venera 10 panorama. It approximates a map geometry and the narrow central part is about 2 m across. It shows the lander sitting on a patch of flat rocky slabs with similar rocky areas on each horizon (probably not very far away, a few tens of meters). Between them is a smooth-looking dark surface, probably gravelly in texture like small patches in the foreground.
November 24, 2025 at 7:46 AM
philstooke.mastodon.social.ap.brid.gy
My pal and occasional co-author Ted Stryk made them - with good intentions, to help people get some idea of what Venus looks like on the surface, because the Russian panorama format is harder to understand. I'm not sure it is really a good idea to do this just because people can get the wrong […]
Original post on mastodon.social
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November 23, 2025 at 7:44 AM
philstooke.mastodon.social.ap.brid.gy
We have seen the Venera 9 and 10 panoramas, but take a look at this from the Planetary Society:

https://www.planetary.org/space-images/rectified-vs-original-venera-9-and-10-panoramas

(presented without any explanation on that page). This version has more detail […]
Original post on mastodon.social
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November 23, 2025 at 7:37 AM
philstooke.mastodon.social.ap.brid.gy
Here is an old Soviet version of the Venera 10 image, a bit too contrasty so details get lost especially at the horizon. But what we see is different from Venera 9's boulders. This is a nearly flat area with platy slabs of rock interspersed with darker […]

[Original post on mastodon.social]
A Russian image of the Venera 10 panoramic image. It extends from horizon to horizon at left and right, and shows the foreground in the middle. Flat slabs of rock cover about half of the surface with gravelly soil between them. Two objects sit on the surface, a lens cover from the camera and a densitometer instrument on a short arm which was dropped on the surface o measure its hardness.
November 22, 2025 at 7:40 AM
philstooke.mastodon.social.ap.brid.gy
OK, what did Venera 10 see? This is the link I gave earlier to Don Mitchell's page about Venus images:

http://mentallandscape.com/C_CatalogVenus.htm

and here is the raw Venera 10 image:

http://mentallandscape.com/C_Venera10.jpg

His expert processing gives us this […]
Original post on mastodon.social
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November 22, 2025 at 7:29 AM
philstooke.mastodon.social.ap.brid.gy
If Venera 10 landed in the hills, I might expect a landscape similar to that at Venera 9's site, lots of blocks where the rock has been broken by dense patterns of faults. But it didn't see that. Tomorrow we will see what the second image of the surface of Venus revealed.
#venus #venera10
November 21, 2025 at 7:34 AM
philstooke.mastodon.social.ap.brid.gy
The south part of the map contains a large volcanic shield (Samodiva Mons) which has released lava flows showing up as brighter lobate markings extending north and east from the shield. The 300 km circle is the landing location - it could be anywhere in there. The closeup, 100 km wide, shows the […]
Original post on mastodon.social
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November 21, 2025 at 7:30 AM
philstooke.mastodon.social.ap.brid.gy
Venera 10 landed in the area shown here at two scales - at left a map spanning 500 km shows major landforms, at right, full Magellan resolution gives us details of part of the landing ellipse. We see mixed geology - the dark areas are smooth (ish) plains […]

[Original post on mastodon.social]
Two maps of the Venera 10 landing site. At left a context map shows bright and dark areas, the bright parts being a hilly area cut by many faults and the dark areas being smoother surfaces probably covered with sediments. A mountain in the south part of the map is a volcano, and flows extend from it to the north and east. Venera 10 could have landed anywhere in a 300 km diameter circle filling much of the map. At right the central part of that landing region is shown in more detail revealing plains cut by ridges and fractures, and part of the hilly area.
November 21, 2025 at 7:24 AM
philstooke.mastodon.social.ap.brid.gy
Venera 10 launched 6 days after V9 (14 June '75) and landed 3 days after its sibling (25 October). This map shows the area. Like Venera 9 it was east of Beta Regio, but 1500 km further south. As with all landers so far the target was essentially unknown, only […]

[Original post on mastodon.social]
A map showing the landing area of Venera 10 in 1975. The site is southeast of Beta Regio in an area which was essentially unknown at the time but now seen (in Magellan data) to consist of mixed bright and dark - rough and smooth - patches. What kind of landscape did Venera 10 land in?
November 20, 2025 at 7:17 AM
philstooke.mastodon.social.ap.brid.gy
... but when Magellan images became available they attracted more attention […]
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November 19, 2025 at 7:28 AM
philstooke.mastodon.social.ap.brid.gy
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 […]
Original post on mastodon.social
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November 19, 2025 at 7:20 AM
philstooke.mastodon.social.ap.brid.gy
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
November 18, 2025 at 7:47 AM
philstooke.mastodon.social.ap.brid.gy
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 […]

[Original post on mastodon.social]
The same map as in the last post, but a distant hillside is separated from the intervening horizon to suggest the valley we can't see into. Also this map has been rotated 90 degrees clockwise, a reminder that as far as I know we have no idea what the orientation of the map should be.
November 18, 2025 at 7:43 AM
philstooke.mastodon.social.ap.brid.gy
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 […]
Original post on mastodon.social
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November 18, 2025 at 7:35 AM
philstooke.mastodon.social.ap.brid.gy
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 […]

[Original post on mastodon.social]
A Venera 9 panorama projected into a rough map geometry. The narrow 'neck' in the middle is about 2 m across. I don't really know how far out the ends should reach.
November 17, 2025 at 8:08 AM
philstooke.mastodon.social.ap.brid.gy
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 […]

[Original post on mastodon.social]
A Russian version of the Venera 9 panorama. It is very high contrast, but shows large rocks littering the surface and a horizon on the right. At left an apparent horizon is a local ridge and a distant rocky surface is visible beyond it. Text below the image says that it was processed by the Academy of Sciences of the USSR.
November 17, 2025 at 8:04 AM
philstooke.mastodon.social.ap.brid.gy
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 […]
Original post on mastodon.social
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November 16, 2025 at 8:16 AM
philstooke.mastodon.social.ap.brid.gy
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 […]
Original post on mastodon.social
mastodon.social
November 16, 2025 at 8:14 AM
philstooke.mastodon.social.ap.brid.gy
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 […]
Original post on mastodon.social
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November 16, 2025 at 8:05 AM
philstooke.mastodon.social.ap.brid.gy
The link I posted earlier shows the Venera 9 panorama - here is the image in its raw form:

http://mentallandscape.com/C_Venera09.jpg

Don Mitchell explains how it was taken. A scanner runs from left to right across the scene, looking out at the horizon at left and right but down at the […]
Original post on mastodon.social
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November 16, 2025 at 7:56 AM
philstooke.mastodon.social.ap.brid.gy
If fractured cut the lava channel they are younger than the channel. It's hard to tell where the lava came from, probably one of the set of north-south fractures west of the channel. The 'chasma' is a broad rift valley. The image in this post shows the site […]

[Original post on mastodon.social]
A full resolution (100 m/pixel) image of the Venera 9 landing site. Dark rectangles are places where image data was lost as the spacecraft switched tracks on its tape recorder. The image shows many fractures cutting the surface. A small volcanic cone is visible 75% of the way down the image near the right edge.
November 15, 2025 at 7:40 AM
philstooke.mastodon.social.ap.brid.gy
I missed a day so I will do two maps today. We are zooming in on the Venera 9 landing site. Yesterday it looked rough. This map shows a very fractured surface, cracks large and small all over the image. There were some gaps in radar coverage which I filled in […]

[Original post on mastodon.social]
A Magellan radar mosaic covering an area 500 km across including the landing area of Venera 9 on Venus. The surface is cut by many fractures which show up as white lines. A circle 300 km across shows the region of the landing site.
November 15, 2025 at 7:29 AM