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Vega At Venus
Paolo
post May 5 2007, 02:44 PM
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I have an AWST article that says that the Vega buses were occulted by Venus and performed radioccultation experiments. However, no results were apparently ever published and the occultation is not mentioned anywhere else. Anybody knows anything more?
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bobik
post Nov 19 2017, 05:23 PM
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What did happen with the Vega 1 lander during the descent through the atmosphere of Venus? In his book Infinity Beckoned, Jay Gallentine wrote, based on an interview with Viktor Kerzhanovich who was responsible for the Doppler measurements:
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The lander continued its plummet. Forty-five minutes of surf and counting. But with only ninety-five thousand feet remaining, disaster spat once again. Call it a “shock layer,” call it “lightning clouds”: planetary scientists can’t agree on a name but the effect is the same regardless. An incredible surge of energy buffeted the Vega 1 lander, flinging it back upward at seventy miles an hour and fooling the urn into thinking it was already on the ground. With absolutely nothing at its feet the soil drill fred up, probing for scratchy rock that wasn’t there.

This sounds quite incredible. Strangely enough, it seems no scientific paper which details these Doppler measurements was ever published.
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climber
post Nov 21 2017, 12:31 PM
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I guess we have to be patient, this topic is active once every 10 years wink.gif


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JRehling
post Nov 22 2017, 10:54 PM
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I hadn't heard of this Vega anomaly before, but it makes me curious as to whether or not it is related to the Pioneer Venus anomaly. To standardize units (odd that the Soviet mission has values reported in feet!!!), the Pioneer Venus probes encountered an anomaly at 12.5 km while this Vega anomaly was at 29 km – much higher.

There is a bit of an implicit assumption that the worlds we probe are in a steady state, although we know this not to be true. I like to use hurricanes as an analogue. Only a very tiny fraction of the Earth's surface experiences hurricane conditions at any point in time, but they do exist, and if your probe hit one, you'd witness something remarkable and perhaps essential to the atmosphere's thermal budget, but very atypical.

Maybe Venus has some wild stuff going on in that opaque atmosphere at layers we've never probed with any consistency.

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nprev
post Yesterday, 09:18 AM
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Yep. With an atmosphere of that depth and density along with so much incipient solar energy it is perhaps surprising that Venus is as calm as it seems to be. Small-scale windstorms doubtless occur far more frequently than we've been able to remotely observe.


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A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Paolo
post Yesterday, 07:54 PM
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this is what I wrote on the subject in my book "Robotic Exploration of the Solar System - part 2"

QUOTE
Meanwhile, the lander, having released its parachute at a height of 47 km, was freely falling. It had begun to report data immediately upon being extracted from the entry shield. About 15 minutes prior to landing, it suffered a major problem. The strong turbulence and wind buffeting led the 8-sensor accelerometer to believe that the landing had occurred. This initiated the surface activity, starting with the drill, which collected air! Remarkably, this occurred near the altitude at which all of the Pioneer Venus atmospheric probes had experienced instrument failures, suggesting that they may have suffered intense vibration.
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