Venera Images, VENERA 13 fully calibrated image |
Venera Images, VENERA 13 fully calibrated image |
Sep 14 2005, 09:26 PM
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#1
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Senior Member Group: Members Posts: 1089 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
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Jan 9 2006, 09:22 PM
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#2
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
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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Jan 9 2006, 10:14 PM
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#3
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
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! 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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Jan 10 2006, 04:24 PM
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#4
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
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! 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, ( 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 |
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Jan 10 2006, 04:26 PM
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#5
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
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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Jan 10 2006, 04:57 PM
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#6
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
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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Jan 10 2006, 07:30 PM
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#7
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Senior Member Group: Members Posts: 1636 Joined: 9-May 05 From: Lima, Peru Member No.: 385 |
QUOTE (RNeuhaus @ Jan 10 2006, 11:57 AM) 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 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 |
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