That's an interesting idea. I'll have to look into how to generate an image for QVR. I've used it (and its inventors are friends of mine, in fact), but I've never tried to generate content for it. Does the standard Quicktime plug-in everyone has show QVR images?

Venusian Reality?


Might be fun except for the screaming and combusting.

The temperature on Venus is approximately the same as an oven in self-cleaning mode. But the dense high-pressure CO2 atmosphere would greatly increase heat conduction, and super-critical CO2 behaves like a non-polar solvent. It's not a highly oxydizing atmosphere, so there would not be flaming combustion. Someone stepping out in shirt sleeves would be french-fried in mid air and eventually reduced to a char coal figure.

So, important safety tip.

Yes, it should.

The moment 90 atmospheres of furnace-hot CO2 starts to pour down your throat, I would imagine that screaming's not really going to happen.

But it's interesting that the view now feels so "normal". It could almost be an Icelandic image, or perhaps the top of a Scottish munro on an overcast day - walk over there and look down into a lochan. Maybe surprise a grouse behind that rock - the real Venusian environment doesn't seem to come across in this picture much if at all, whereas, in the originally portrayed slices, there was somehow a sense of a truly alien and hellish world, snapped in a few precious minutes between landing and melting.

For me, that makes it such a remarkable picture. Don's created our sister planet from scraps, and given us a familiarity that I certainly haven't had before. And I suppose that means we can now wonder - especially on the back of the MERs - about exploration. What lies over that edge, what vistas would greet us?

Andy

AndyG

Here you go.

Click to view attachment

Toastie! Thanks - that's more like it. Now if only it had had a video camera on it!

Andy

That's just brilliant, though I would expect a more orangey-brown colour for the sky and the distant hazy hills.

I'm not sure I understand. What is the coloration for?

AndyG was complaining that the "Real Venusian Environment" didn't come through, so I added a little bit of red to the picture to give it that "this is hot as an oven" look to it.

Ah! :-)

Of course the sky of Venus is actually bright orange. Everything is bathed in orange light, from a uniform hemispherical source. The cloud layer, far above, is not visible from the surface. Strong rayleigh scattering causes the terrain at a distance to be lost in a greenish-yellow haze that eventually merges with the orange color of the sky.

At night, the ground at low altitudes might glow faintly red from the heat, but it is just barely hot enough for that. I'm not sure if you could see it or not.

Colors from the Venera probes have never been rigorously calibrated. First of all, the radiometric response of the camera that was used before is incorrect. The spectral response of the color filtes is known, but not the relative gain correction. I have talked with Gektin about this (the camera designer), and he is searching for some data that will permit absolute calibration of the color. Namely, the spectrum of a colored calibration lamp, which was imaged during the video retrace interval.

The Russians knew what to do in theory. They realized you have to solve an integral equation to recover color from the spectral responses of sensors. Bravo for them, because I don't think any American space photos have ever been processed with that sophistication. But having written that in their paper, the Russians were unable to perform the calibration, because they lacked the necessary computers.

I recall that all the drop probes from the Pioneer Venus Multiprobe mission reported
an increase in infrared glow before those sensors were overwhelmed. Any ideas on
what it might have been?

You have done so much work already to make the place look 'real' and obviously have your own mental picture of the true colouration. Why not share it with us? - perhaps day and night versions, assuming the ground glow is just visible?

How very typical both of Russia and the US. As somebody said "as long as it can bew done with paper and pencil the russians are unbeatable".

tty

A new work on the Venera 9 - 14 images was presented 2 days ago by well known Venus scientist Dr Ksanfomality at the European Planetary Science Congress 2010:
http://meetingorganizer.copernicus.org/EPS...PSC2010-273.pdf
Unfortunately, no more details yet...
BUT, having myself analysed all the Venera data available, I don't think there is much more to be seen : all features on the horizons were enhanced and the Venusian sky shown already in this UMSF Forum topic.
_______________________________

[quote from the abstract with no images published] :
"In 1970-80 the VENERA 9, 10, 13 and14 probes imaged the surface of Venus at landing
sites. These TV photos have been published by many scientific editions, either original or
processed. Since the visits of the pioneering VENERA landers, there have been steady
efforts to achieve a better processing of the original images for following analysis. This
paper is devoted to the description of few segments of re-processed images at their right
and left hand sides, demonstrating features not noticed earlier (or ignored due to their
distortion). Using this re-processing, interesting images that included both horizon and
sky of Venus were produced. In the new images next mount chains or valley slopes
appeared at the horizon line."

this is an old thread . has the color issue been better solved since '06
As i recall , when i did my map and colorized the radar data , there were some images redone to get the color strip on the lander "closer" to there colors .
But did not take into account the effects from the pressure . and that the rocks would most likely have a slight bluish tint ( if they were on earth)
In the end I gave up and just used an artistic color
Click to view attachment

A collection of surface panoramas: 180° for Venera 9 and 10, 360° for Venera 13 and 14. Reprojections are according to various suggestions on this forum. Horizon topography is probably not real, but due to inaccuracies of the reprojections (which are not strictly geometric anyway).

Nice job, Sariodil. I'm not sure I agree with your connections between features near the horizon for Venera 13, but it looks good anyway. I have often thought of trying to map these landing sites, so just playing with your images I came up with these for Veneras 13 and 14. Very preliminary, but it gives an idea of what might be done eventually. The orientations of these images (where north is, in other words) is unknown.

Phil

Click to view attachment

Click to view attachment

All these re-projections and reprocessing you've accomplished here just whets my appetite for new missions. The Venusian surface has been neglected for far too long...

I´m not sure about the Venera 13 horizon either. When the horizon in the Camera I image came out concave in the reprojection, I thought it could be a valley floor at a lower elevation than the hills in the adjoining part of the Camera II image. On second thought, however, smooth concave valley floors are probably not what you would expect on a planet with so little erosion.
But if erosion has no part in shaping the surface, could the gaps in the hills on the horizon be the surface expression of faults? If so, one could align them with the fault azimuths on Magellan images of the landing site to narrow down the possible orientation of the panorama.

Good suggestion, but the areas covered by these reprojected images would span at most a few tens of pixels in Magellan images, and at locations in the images uncertain by many tens of kilometers, so it is very unlikely that we could do something like that.

Phil

Thanks for your contribution. You did an interesting work.
The horizon of Venera 9 should be adjusted because the lander was sitting on a slope with a 20° tilt...
Click to view attachment

It's not easy to extrapolate much from the Venera images. I'm yet to see a good geometrical correction of all the distortions.

Those "U" shaped strips are approximations, and looking at them I always have the feeling that the spacecraft is on lower ground relating to the horizon. The imaging system is similar to that of Viking, but the scanning is made at an angle in relation to the horizon.
The Venera cameras were about 2m above the surface but, as you move from the center to the edges towards the horizon, the image looks like they were taken with a lower point of view (more like Pathfinder).
All of this makes the horizon interpretation much harder. What looks like a slope might be an horizontal feature...

Ted Stryk has given the Venera 9 and 10 images a bit of a makeover.
http://planetimages.blogspot.com/2014/07/s...us-in-1975.html

Good catch! Why did I never notice the hills at Venera 9....

Interesting results with those horizon features.
My only fear is that the results look too good. Easy to mistake the generated images for the actual ones...
Other than that, I still see some geometric distortion in the vertical axis. But I know from self experience that this is a difficult dataset.

The problem is that there are less that 50,000 pixels showing the surface, and so I used somewhat distorted repeats to fill gaps in the case of Venera 9. The hills to the left can be seen at the edge of the original panorama. Many versions I've seen have the horizons so overexposed that the hills are lost. The middle hill is of course a creation created from cloned bits of the stuff on either corner...here was my thinking...there are relatively big hills on the left, and the ground is choppy on the right-hand horizon. Venera-9 is itself on a slope. So there is little chance that the horizon is flat between the two corners of the panorama. It took dozens of times going back to the drawing board before I got something that looked half-way decent. Venera 10 was much easier.
I was also trying to project it to look as though one is looking from one point rather than moving along the scene is the camera scanned...that improves some things, but creates other geometric issues.
As I said, everything is from cloned portions of the actual image data. Nothing is drawn outright. That might be an interesting experiment.

The idea of providing a "synthetic" scene is interesting.

You could to the same using elements from earth photos. As long as rock size, distribution, overall shape and composition are the same, it's a valid experiment. I'd go for that and totally skip the original imagery.

Venera 14 landed 33 years ago today. I wrote a new blog entry about it. http://planetimages.blogspot.com/2015/03/v...hy-we-need.html

Very nice, Ted! Putting the images where they can be compared is very evocative. And yes, it's tantalizing to think of how much of Venus we haven't seen. One ground-buzzing airplane taking hi-definition video as it zoomed along a long ground swath could increase our ground-level imagery by a few orders of magnitude. If only the will were there...

Thanks. I love the idea of a balloon that rises and falls with the day so that it touches down in multiple locations. I've added a second interpretation of the color in the combined image.

It's time to go back and explore!

My short paper just out in Icarus on the observed probability distribution of Venus surface winds (useful for lander design, as well as evaluation of aeolian transport) . It is remarkable that on only two ~hour long occasions when aeolian transport of regolith could possibly have been observed (by Venera landers), it was seen on one. Typically one has to wait months to see something happen on Earth or Mars - Venusian sediment is therefore probably always on the move, something that might be observable with radar interferometry, as well as lander observations...
(link to free pdf valid for 50 days)



http://authors.elsevier.com/a/1RvsN4L-YESvT

Thanks for sharing this with us, Ralph. In your estimation, were the Veneras on the high or low side of optimum landing configuration (if that makes sense) given your analysis?

None of them fell over, so the design can be claimed to be robust. But the question of optimality is meaningless without a stated success criterion (i.e. given an [unknown]
surface slope distribution and given an [unknown, but kindof handwavy-estimated here] wind distribution, and given a requirement for e.g. 99% success THEN a certain
design can be considered optimal)

The fundamental point is that any planetary landing entails uncertainty (qv Philae) and thus no finite-cost design can offer 100% reliability. Thus rational design and
evaluation entails the statement of an acceptable degree of risk. Where terrain (or meteorological) factors introduce an entirely stochastic element to the landing
dynamics, an optimal mission solution may be to build two 90% landers to achieve an overall 99% chance of safe landing.

Understood. My question was quite poorly constrained. Thanks!

Ralph, that report sounds promising for powering a long-duration lander with wind power. 90 times Earth's atmospheric density, would mean the .4 m/s wind is equal to ~3.8m/s, close to cut-in speed for a decent wind turbine. And I would assume windier times and locations are possible? Would it be a good assumption that windspeeds on Venus' surface don't change quickly, since the rotation is so slow?

I guess a space-based instrument won't be able to monitor windspeeds - on Earth the __Scat family of satellites use ocean roughness as a proxy for surface windspeed. I propose a mission to drop a load of neutrally buoyant reflective strips onto Venus along with a radar platform to monitor their distribution.

If the (total) cost of an estimated p=99% mission success is more than double that of a p=90% mission, that formula presents an excellent argument for building and launching duplicate missions, as in the case of Viking or Voyager or MER. Because 81% of the time, you may then hope to realize not one but two successes. (In each case, the second success might be considered partially redundant, but only partially.)

Unfortunately, here in reality the relationship between cost and probability of mission success is not quantifiable with any precision. I'm not even sure that spending more money increases probability of success in all cases.

Agreed. Many in-situ hazards are of unknown incidence, and knowledge of their incidence is exactly the kind of knowledge that the mission is meant to acquire, so there's a Catch-22 there in principle.

Not only Huygens but also an early Venera lander were designed to float. This was overly cautious in both cases, as it turned out. The designers could have thought and spent all they wanted, but ultimately, some exploration had to be done to ascertain whether or not flotation was required. They could have spent a trillion dollars on it and not gotten a better answer than they did by actually flying a mission and seeing what the surfaces of Venus and Titan are like.

Then again, the next Venus lander may unluckily sink into a pond of molten tin. It's hard to prove otherwise until we've explored Venus thoroughly.