I think Venera 13 is more Meridiani-ish.

Yes. My mistake!

Now, if you can pull some festoon bedding out of those old Soviet images...

Bob Shaw

Here is a Venera 14 compilation. I can't get much of a super-resolution effect out of camera 2 (the full color pan), owing to the really crappy quality of the original images.

The consensus now is that what we're seeing in both the Venera 13 and 14 photos (and probably those from Venera 9 and 10) is not regular rock, but sheets of fine dust (probably impact ejecta) that's been fused into layers of friable rock by the chemical reactions that go on between soil grains and the trace gases in Venus' super-hot, super-pressurized atmosphere. Both the Venera 9 and 10 density measurements and Venera 13's penetrometer revealed the stuff to be lower in density and hardness than regular basalt (I never thought those instruments would reveal anything interesting, but they did). And this presumably explains the startling absence of any signs of aeolian movement in Magellan's images, despite the fact that Venus' low surface breeze of just 1 meter/sec should have been enough to move dust and sand around on its surface. As it is, the only dunes we see on Venus seem to be those piled up around giant impact craters, presumably by the air blast associated with each impact.

I have, when I can find it, a conference abstract on the simulation of this fusion process in an Earth lab.

Venera 14 looks like someone took a vacuum cleaner to Meridiani.

It's striking how much, at a glance, the Huygens surface picture looks like Venera 9's.

It's also interesting that Venus, Mars, and Titan all have orangeish light coming through their atmospheres. If you want to see another world with a blue, purple, green, yellow, or red sky, you're going to have to try another solar system.

Unless perhaps you are on a blimp in the atmosphere or Uranus or Neptune, which I am assuming would produce a blue sky.

Seriously, it is caused by an interesting set of circumstances. Earth's sky appears blue because blue light is more easily scattered, while red light makes it to the surface with less trouble. Venus is so good at scattering that hardly any blue light reaches the surface. I am guessing that Titan is similar, although, unlike Venus, I have not seen spectra (which must exist from Huygens). Venus and Titan of course have thicker atmospheres than Earth. Mars should certainly have a blue sky, it was surmised by Viking scientists, but suspended red dust wrecks havoc on the idea. I think truely green or yellow skies are going to be rare in the universe. Blue (which I am assuming would be Violet if the human eye weren't more sensitive to blue light) and red are end members of the visible spectrum, meaning that blue/violet and red skies could mean true peaks in infrared or ultraviolet. To be green or yellow, the peak would have to truely be in that spectral range.

Here is the completed version of that set. Because it was a particularly good area in the data, I made an even more enlarged version of that peculiar rock in the camera 2 pan. Also, I colorized the area for which there was no color data.

You are right,. I posted for someone if I know in others topics. The easiest thing is to ask someone if he knows.

I have already searched and it seems that there is no surface temperature statistics between day and night. There is only temperature information that is related to the altitude.

I realized that the only one temperature might be due to the greenhouse effect has kept the surface temperature to be more or less constant between day and night.


Venera 7 has no information about the landing place and position to the Sun.

Venera 8 landed at 09:32 UT at 10 degrees south, 335 degrees west, in sunlight about 500 km from the morning terminator. The lander mass was 495 kg. It continued to send back data for 50 minutes, 11 seconds after landing before failing due to the harsh surface conditions. The probe confirmed the earlier data on the high Venus surface temperature and pressure (470 degrees C, 90 atmospheres) returned by Venera 7, and also measured the light level as being suitable for surface photography, finding it to be similar to the amount of light on Earth on an overcast day with roughly 1 km visibility.

Venera 9: The landing was about 2,200 km from the Venera 10 landing site. The Lander touched down on the surface of Venus on October 22, 1975 at 5:13 UT, about 32° S, 291° E with the sun near zenith. It operated for 53 minutes, allowing return of a single image. Venera 9 landed on a slope inclined by about 30 degrees to the horizontal.Preliminary results indicated: (A) clouds 30-40 km thick with bases at 30-35 km altitude, ( atmospheric constituents including HCl, HF, Br, and I, © surface pressure about 90 (earth) atmospheres, (D) surface temperature 485 deg C, (E) light levels comparable to those at earth midlatitudes on a cloudy summer day, and (F) successful TV photography showing shadows, no apparent dust in the air, and a variety of 30-40 cm rocks which were not eroded.

Venera 10:The landing was about 2,200 km distant from Venera 9. The Venera 10 Lander (bottom) touched down on the surface of Venus on October 25, 1975 at 5:17 UT, about 16° N, 291° E. The Lander was inclined about 8 degrees. It returned this image during the 65 minutes of operation on the surface. The sun was near zenith during this time, and the lighting was similar to that on Earth on an overcast summer day. Preliminary results provided: (A) profile of altitude (km)/pressure (earth atmospheres)/temperature (deg C) of 42/3.3/158, 15/37/363, and 0/92/465, ( successful TV photography showing large pancake rocks with lava or other weathered rocks in between, and © surface wind speed of 3.5 m/s.

Venera 11: It made a soft landing on the surface at 06:24 Moscow time on 25 December after a descent time of approximately 1 hour. The touchdown speed was 7-8 m/s. Information was transmitted to the flight platform for retransmittal to earth until it moved out of range 95 minutes after touchdown. Seem to be failed to transmit data.

Venera 12: The touchdown speed was 7-8 m/s. Information was transmitted to the flight platform for retransmittal to earth. until it moved out of range 110 minutes after touchdown. (no information about landing place).

Venera 13: . Venera 13 landed about 950 km northeast of Venera 14 at 7 deg 30 min S, 303 E, just east of the eastern extension of an elevated region known as Phoebe Regio. The area was composed of bedrock outcrops surrounded by dark, fine-grained soil. After landing an imaging panorama was started and a mechanical drilling arm reached to the surface and obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample determined by the X-ray flourescence spectrometer put it in the class of weakly differentiated melanocratic alkaline gabbroids. The lander survived for 127 minutes (the planned design life was 32 minutes) in an environment with a temperature of 457 degrees C and a pressure of 84 Earth atmospheres. The descent vehicle transmitted data to the bus, which acted as a data relay as it flew by Venus.

Venera 14: Venera 14 landed about 950 km southwest of Venera 13 near the eastern flank of Phoebe Regio at 13 deg 15 min S by 310 E on a basaltic plain. After landing an imaging panorama was started and a mechanical drilling arm reached to the surface and obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample was determined by the X-ray flourescence spectrometer, showing it to be similar to oceanic tholeiitic basalts. The lander survived for 57 minutes (the planned design life was 32 minutes) in an environment with a temperature of 465 degrees C and a pressure of 94 Earth atmospheres. The descent vehicle transmitted data to the bus, which acted as a data relay as it flew by Venus.


I suppose that the maximum and minimum Venus temperature (mean surface temperature is between 464 and 482 celius degree). These measured temperature corresponds to close to equatorial latitud between 10 and 31 degree South and the Sun was near Zenith during this time (above head).

I am thinking that the polar surface sites must have a slight less temperature, perhaps 450 Celius degree, than the equatorial lines due to greenhouse effect?

Good details about Venus http://www.solarviews.com/eng/venus.htm

Rodolfo



Rodolfo

I know I should double-check this, but I remember reading that Venus' surface is actually warmer at its poles than its equator, plus its night side is warmer than the day side!

Either I am right or I am operating on a 20-year-old memory/data.

Why such strange physics laws?

Venus has very small Tilt of axis (degrees 177.36), so Venus has no typical summer and winter and the temperature in Equatorial line must be warmer all round year and the poles which are not zenith and receive less solar energy and consequently must be cooler but the greenhouse effect might alter these physics laws.

Why is warmer at its poles than its equator and also of nights versus days?
It would be very good that you find the link about the above odd behavior.

Rodolfo

{ I hope I phrase this well enough }

Does any one know the cooling rate for 'earth type' basaltic magma from the time of contact with liquid water to the point it has solidified as compared to the expected cooling rate for the Venusian equivalent of basaltic magma from the time of contact with the Venusian atmosphere to the point of solidification?

Is 1300 psi (or whatever it works out to) CO2 more heat absorbing than H2O at 15 psi ?

Funny if the magma on Venus solidifies faster than the magma on earth in contact with sea water.

Would this effect the forms of the rocks we expect to see?

Sea water on Earth is only at 15 psi at the shoreline (eg, on a beach). The pressure is much higher in locations of typical seafloor magma exposure, and would certainly have a much higher thermal inertia than Venus's CO2. It's also much cooler, which is another factor in the speed of heat propagation.

Water, even at 15 psi, is roughly 1000 times as dense as Earth air. Sea water is even denser. Venus's surface atmosphere is very roughly (no time for math now!) 75 times as dense as Earth air.

Anyone who has stood in a 10 km/h breeze and has also been hit by a 10 km/h ocean wave will appreciate the vast difference. Venus's atmosphere is in the middle.

I found an article which mentions about the temperature of day and night and also of polars: The polar temperature is compensated by the thermal regime of Venus in spite of the fact of the temperatures inhomogenitis between equator and poles that arise from the differential insolation. On the other hand, the night-side temperatures exceed day-side temperatures according to the authors. The thermal asymmetry of Venus was confirmed by data from infrarred radiometry on Venera 9 and Venera 10 orbiters, and in particular from the analysis of limb darkening. The variation of temperature between day and night is due mainly to a change in height of the emissivity layer in the vicinity of upper cloud deck (65-68 km).

Interesting

More detail, click here

Rodolfo

Here are two more shots. An improved horizon pan:



And an improved version of that cool looking rock formation.

Looks to me that if you flipped the rock over it matches with the surface immediately above it

The only problem is that in the full pan, there are many spots that look like the area above the formation with no rock sitting next to them.

Does anyone else remember the "fact" that refraction in the dense Venusian atmosphere would be so strong that you could see the back of your own head? I remember puzzling over that for hours as a kid, but I never really believed it.

Michael

I heard about refraction in Venusian atmosphere...something like "you would have feeling that you are walkin at the bottom of crater with very steep walls even if you are on flat ground...don't remember quite well about that but, seeing the back of your own head????I HAVE NEVER HEARD SOMETHING LIKE THAT...please explain...

That was an old theory, but turned out not to be the case. The Veneras showed the horizon just where it should be, when corrected for their odd imaging system.

I seriously doubt that.

For starters refraction effects happen at interfaces or across density gradients. For the sort of effects described here you would need to have really bizarre density gradients all around you.

Things would probably look a bit different and heat shimmer effects might be more pronounced than on earth but they would be far less extreme than under water on earth for example.

The refractive index of CO2 at STP is 1.000449 (air is 1.000292). The refractive index of a gas changes (very approximately) with density according to (RIx=1+(RIstp-1)*(Dx/Dstp) so the RI of the venusian surface atmosphere is somewhere around 1.04041 (since the Venusian surface atmospheric density is approximately 90x the density of CO2 at STP).

Snells law gives us something to calculate what this would mean for a human in a spacesuit on the surface of Venus. Assuming we have an optically neutral window and we simplify the calculation down to an air (at stp) CO2 (at Venus surface) boundary.
Snell's law : RIi*Sin(Thetai)=RIr*Sin(Thetar)
Thetai = Incident beam angle and Thetar= Refracted beam angle
So Sin(Thetar)=1.000292*(sin(45deg)/1.04041
The refracted beam would be at 42.8deg. Noticable but not significant.
As a comparison for a water:air interface on earth the equivalent refracted beam would be at 32.9deg.

All in all it might be hard to play pool well on the surface of Venus but it certainly wouldn't create any bizarre visual effects.

Unless you count two scorched and imploded skeletons slumped over an incinerated pool table as a bizarre visual effect.

Don Dixon made some paintings of the alleged super refraction of Venus' atmosphere from the surface here:

http://www.cosmographica.com/gallery/portf...fraction%20.htm

http://www.cosmographica.com/gallery/portf...097-Inferno.htm

As a bonus, here is Dixon's rendition of what the Pioneer Venus Day Probe probably looked like as it sat on the planet's surface and radioed back to Earth for 67 minutes in 1978:

http://www.cosmographica.com/gallery/portf...enusLanding.htm

...but now we know that's not true don't we?
ljk thank you for that links....those images really rock!!!

Yes, if you will note from his headers, the paintings were made in the 1968 to 1974 period, and Dixon even labels one as outdated.

I just thought since super refraction was being talked about here, some folks might enjoy seeing a Venus that never was.

Yes, the first shots of Venus from Venera 9 and 10 turned out to be remarkable for their sheer ordinariness. Not only was there no super-refractive "swimming pool effect" (which had recently become a staple of SF stories about the planet; John Varley's first published story used it and was called "In the Bowl"), but even in those grainy photos it was clear that the horizon was fairly sharp and that the shadows even of small pebbles, despite the dense atmosphere, were quite sharp. In fact, the Soviets had equipped the two landers with floodlights on the assumption that the solar illumination might be too dim to see the surface otherwise! The much better photos from Venera 13 and 14, of course, confirmed all this even more dramatically (and also revealed that fiery orange sky, although I don't know whether that color was predicted in advance).

Scientists have, really, a pretty bad track record when it comes to predicting the optical qualities of surface photos. Remember how astonished everyone was when Viking 1's first black-and-white photos showed a light-colored sky (which later turned out to be pink) instead of the deep violet sky everyone had expected? They even predicted that deep violet sky again for Pathfinder, since there was less dust in the air at the time of its landing.

The big reason Soviet scientists thought Venus would be so dark at its surface is that the Venera 8 lander reported dim lighting conditions in 1972. Venera 8 did this with cadmium sulfide photoresistors (try to fit that phrase into your next dinner conversation), as it carried no cameras.

But what they did not seem to take into account was that the Sun was only 5 degrees above the horizon at the Venera 8 landing site when the readings were taken.

ftp://ftp.seds.org/pub/info/newsletters/e...93/jasa9303.txt

Soviet Veneras and Mars: first entry probes trajectory reconstruction and science

Viktor Kerzhanovich, Jet Propulsion Laboratory,
Pasadena, CA, USA

Konstantin Pichkhadze, Lavochkin Association,
Moscow, Russia

Presented to International Workshop on Planetary
Probe Atmospheric Entry and Descent Trajectory
Analysis and Science

Lisbon, Portugal, 6-9 October 2003

http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/37338/1/03

Though most of the data and probe images are on the Veneras, there are some very nice diagrams of Mars 3 and 6 and data charts on the Martian atmosphere from Mars 6.

Great find! I had seen the Mars 6 stuff in an old 1977 paper he wrote in Icarus, but good to see that the dataset is being presented again. Regardless of overall value, it is the first in situ data (other than the mysterious Mars 3 blurb) from the Martian atmosphere and there are only five other decent profiles in existence - it would be a pitty for it to be totally forgotten.

Found this Soviet document from 1969 on their Venera missions up to
Venera 6. Some nice and uncommon (for the West) artwork and diagrams:

http://epizodsspace.testpilot.ru/bibl/venera/obl.html


This whole site is a gold mine of old and not so old Soviet space books
and documents - most of it in Russian, oddly enough:

http://epizodsspace.testpilot.ru/bibl/biblioteka.htm

http://epizodsspace.testpilot.ru/bibl/oblojki/oblojki.html

Yep, that site has been around for some years. Sergey Khlynin did most of the work. He's been a big help to me in my research, especially making some special high-res scans of rare photos.

Don,

your images are amazing !

Old Soviet Images of Venus Yield Fresh Surprises

To many things are happening today...
These Venera(ble) images are breathtaking , I'm impressed by the atmosphere transparency...
Beautiful! We must send a MER (VER) there...

Congratulations on being featured on SPACE.com Don! About time your fantastic images were seen by a wider audience. The one of the hills is literally breathtaking.

Yep! Here too, we can near rim, far rim and far-far rim
Seriously, been used of the original pictures, I've got the feeling to discover a new word. Kind of going from "Phil's polars" to Dilo's, Midnigth Mars, etc...
Thanks so much and congratulations Don.

Congratulations! It is great to see the images in a human perspective.

Thanks guys. NBC picked up the story too (MSNBC). Interesting to see how they fiddled with Leonard's wording and my quotes, and kind of broke most of them. :-)

I'll add a blog entry on my site with a little more explaination about the images.

Don,

Those old Venera images were always appreciated for the close up views of the rocks scattered around the landers. But after viewing your versions, with hills and real horizons, Venus has become a real PLACE for me, just as Gusev and Meridiani are real places. Thanks so much. Your efforts are really appreciated.

David

Thanks, it was an afterthought really, but I'm glad I did it. My brain definately sees the terrain better in perspective, even though I am not seeing an new pixels.

I added a little extra info about the project on my blog: Venus in Perspective

Yes, thanks, Don! In particular, the "hills" remind me a lot of a lava dike that has breached and allowed a fan-shaped flow of lava to come in and pave the area upon which the lander sits.

Fascinating place!

-the other Doug

I was delighted to see Don's Pictures. I couldn't believe it since I have seen a partial picture. Below the Venusian atmosphere looks so transparent even many kilometers.

Rodolfo

Very interesting and well-done. One question: the "channel" in the mid-field of the image on your blog page seems suspiciously aligned with the edges of the image coverage. Is there really reason to think this is anything but an artifact of your processing? I wouldn't want people doing photogeology on the basis of seeing this feature if there isn't real evidence for it.

The persective images are derived from superimposing different projections, with photoshop. I explain that on my latest blog entry. Geologists would not use an image like that to do any kind of analysis. They are just meant to convey the big picture of what the terrain looks like, in a familiar camera perspective. For photo interpretation of geology, you would look at the new unprojected images, with the improved radiometric response function, or even the individual perspective projections, like the three partitial images I show.

Soviet researches, at one time, reprojected the Venera images into the cylindrical form returned by the Viking Mars lander, to help make comparisons in a projection that planetary geologists had become use to studying.

Well done, Don.

You've managed to make me beat my shortest-lived wallpaper ever record, when yesterday's stunning LPOD Plato shot was bumped off my monitors this morning to be replaced with your Venusian Hills.

Beautiful imagery - I have to agree with David with regards to making Venus a place, with work as good as this.

Andy

Don, my first attempt to produce vertical/polar projections showed unacceptable distorsion in the lower part, due to the fact that your image isn't an equirectangular projection but is probably closer to a wide-angle image with rectilinear correction (like some processed hazard cam images from MER).
After applying to the original some "pincushion" distorsion and assuming 90 deg FOV, results appear better (vertical projections for V13 and 14 respectively):
Click to view attachmentClick to view attachment
Do not know real scale (should be a 0.5cm/pixel assuming a camera height of 1m); someone can calculate based on the probe features...
Here the corresponding pseudo-polars:
Click to view attachment Click to view attachment

The images were originally 800 x 600, and the sky was later extended by 200 pixels. So the camera is perspective projection, but it is pointing downward a little. Just delete the upper 200 pixels and try. Here is the code that made the image:

Don,

beautiful work. fantastic hills. I will now plan to show them at our astronomy club meeting in Princeton tonight as part of a review of recent discoveries and the Viking 30th anniversary

ken

http://www.princetonastronomy.org/

You haven't worked with a lot of geologists, have you?

Hehe. Well I can say that Alexander Bazilevsky or Jim Head would know better. I could put some sort of "cape does not allow wearer to fly" warning on my picture, I suppose. :-)

You're in the news mr DonPMitchell.

A quicktime VR would be nice.