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Venera Images, VENERA 13 fully calibrated image
JRehling
post Jan 9 2006, 08:29 PM
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QUOTE (RNeuhaus @ Jan 9 2006, 07:08 AM)
Very different type of terrain. Mainly rocky, no sand or silica dust. No water erosion signs. Interesting.

Rodolfo
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While these new presentations are aesthetically wonderful, the old, unnatural-looking presentations of Venera imagery allowed this level of observation, so they are not new to us. The four sites are quite different, with boulders atop/embedded in soil at two sites and large, plate sheets of rock at the other two. It is certainly the case that water erosion could not have acted on any portion of Venus's surface since the last major resurfacing event (if ever) -- if there are any ancient surfaces that show past water influence of any kind, we will have to hunt them down very carefully. Such formations may not exist at all.

There is sand/pebble soil visible in Venera 9 and Venera 13 surface views. Fine dust may be rare. It seems likely that chemical production of dust is not a major phenomenon, and mechanical processes that produce dust seem to be rare also. Because the surface temperature is very constant, there are only light winds, so dust will not beget new dust much.
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tedstryk
post Jan 9 2006, 08:34 PM
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QUOTE (JRehling @ Jan 9 2006, 08:29 PM)
While these new presentations are aesthetically wonderful, the old, unnatural-looking presentations of Venera imagery allowed this level of observation, so they are not new to us. The four sites are quite different, with boulders atop/embedded in soil at two sites and large, plate sheets of rock at the other two. It is certainly the case that water erosion could not have acted on any portion of Venus's surface since the last major resurfacing event (if ever) -- if there are any ancient surfaces that show past water influence of any kind, we will have to hunt them down very carefully. Such formations may not exist at all.

There is sand/pebble soil visible in Venera 9 and Venera 13 surface views. Fine dust may be rare. It seems likely that chemical production of dust is not a major phenomenon, and mechanical processes that produce dust seem to be rare also. Because the surface temperature is very constant, there are only light winds, so dust will not beget new dust much.
*


I have always thought the Venera 9 site looks like a Viking landing site.


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RNeuhaus
post Jan 9 2006, 09:22 PM
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I think that the dust is the product of desintegration of rocks due to some kind of erosion of wind, water, or land along with the temperature changes, or chemical reaction. May be due to the radioactive decay of minerals that desintegrate the rocks into the dust.

So, Venus has "no water", on the surface has very low wind speed and very low temperature changes (I doubt it, since Venus has night that I don't know how much is the temperature drop between the day (470 Centigrade) and night ??. The rest venusian dust might be due to the chemical reaction or radioactive decay of some rocks?

Rodolfo
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JRehling
post Jan 9 2006, 10:14 PM
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QUOTE (RNeuhaus @ Jan 9 2006, 01:22 PM)
So, Venus has "no water", on the surface has very low wind speed and very low temperature changes (I doubt it, since Venus has night that I don't know how much is the temperature drop between the day (470 Centigrade) and night ??. 
*


I'm curious -- if you don't know how much the temperature drop is between night and day on Venus, but you are interested enough to discuss the matter, why don't you look it up on the Internet before posting?

It seems odd to me that a poster perceiving himself to lack information would have a greater motivation to analyze a phenomenon (and post the un-informed analysis) than to get basic information about the phenomenon. The information is not hard to come by, and un-informed analysis is all too easy to come by! wink.gif

Put another way: If you have ten units of personal energy, which do you think helps the board more: five researched topics and five informed posts, or ten uninformed posts?
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Bob Shaw
post Jan 9 2006, 11:10 PM
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QUOTE (tedstryk @ Jan 9 2006, 09:34 PM)
I have always thought the Venera 9 site looks like a Viking landing site.
*


Or even the latest Meridiani images!

Bob Shaw


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tedstryk
post Jan 9 2006, 11:12 PM
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QUOTE (Bob Shaw @ Jan 9 2006, 11:10 PM)
Or even the latest Meridiani images!

Bob Shaw
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I think Venera 13 is more Meridiani-ish.


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Bob Shaw
post Jan 9 2006, 11:24 PM
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QUOTE (tedstryk @ Jan 10 2006, 12:12 AM)
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


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tedstryk
post Jan 10 2006, 02:43 AM
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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.



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Guest_BruceMoomaw_*
post Jan 10 2006, 03:01 AM
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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.
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JRehling
post Jan 10 2006, 03:04 AM
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QUOTE (tedstryk @ Jan 9 2006, 03:12 PM)
I think Venera 13 is more Meridiani-ish.
*


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.
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tedstryk
post Jan 10 2006, 03:16 AM
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QUOTE (JRehling @ Jan 10 2006, 03:04 AM)
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.


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tedstryk
post Jan 10 2006, 05:02 AM
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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.



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RNeuhaus
post Jan 10 2006, 04:24 PM
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QUOTE (JRehling @ Jan 9 2006, 05:14 PM)
I'm curious -- if you don't know how much the temperature drop is between night and day on Venus, but you are interested enough to discuss the matter, why don't you look it up on the Internet before posting?

It seems odd to me that a poster perceiving himself to lack information would have a greater motivation to analyze a phenomenon (and post the un-informed analysis) than to get basic information about the phenomenon. The information is not hard to come by, and un-informed analysis is all too easy to come by!  wink.gif

Put another way: If you have ten units of personal energy, which do you think helps the board more: five researched topics and five informed posts, or ten uninformed posts?
*

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, (cool.gif 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, (cool.gif 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
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ljk4-1
post Jan 10 2006, 04:26 PM
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QUOTE (RNeuhaus @ Jan 10 2006, 11:24 AM)
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 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.

...

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 13 degree South.

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?

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.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

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RNeuhaus
post Jan 10 2006, 04:57 PM
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QUOTE (ljk4-1 @ Jan 10 2006, 11:26 AM)
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
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