(ORDO NEWS) — Conditions on Venus are so different from those on Earth that most of the processes occurring in its atmosphere and on the surface, we earthlings have never encountered.
And this despite the fact that before the first space missions to this planet, Venus was considered the “twin sister” of the Earth.
One of the most striking facts about Venus is perhaps the presence of metallic “snow” , and the history of its discovery sheds light on some curious details.
On August 10, 1990, NASA‘s Magellan spacecraft entered Venus’s orbit and began radar scanning to “break through” the planet’s extremely dense atmosphere and collect data on its surface.
During the scanning on the tops of the Venusian mountains, a certain coating was found that has an extremely high reflectivity in the radio range. Planetary scientists, studying the data, suggested that these were deposits of iron-containing materials and / or the consequences of erosion (destruction of rocks).
Further research, coupled with experiments in terrestrial laboratories, showed that the mysterious coating is a real metal “snow”, consisting of bismuth and lead sulfides.
As you know, the average temperature on the surface of Venus is 462 degrees Celsius, and this is enough for melting, but not for the evaporation of bismuth and lead.
Thus, the only source of such a large amount of gaseous bismuth and lead on the neighboring planet may be off-scale volcanic activity.
Then thermodynamic conditions at an altitude of about 2.6 kilometers lead to the condensation of compounds that settle on the tops of the mountains.
Studying the past, understanding the present
There are no direct signs of modern volcanic activity on Venus, but we do know of metallic “snow” that covers the tops of a few high mountains.
This allows us to make two assumptions
– Volcanic activity stopped completely relatively recently, but it was so intense that it oversaturated the atmosphere with metals and changed the climate of Venus, which probably once really was similar to Earth
– Rapid volcanic activity changed the climate of the planet, but later subsided and turned into a very rare phenomenon, delivering bismuth, lead and other compounds into the atmosphere.
The probable awakening of volcanoes may be indicated by periodic variability in the concentration of sulfur dioxide in the atmosphere, but this evidence is clearly not enough.
The NASA DAVINCI + and VERITAS missions , scheduled to start in 2029-2030, will help us unravel the “volcanic mystery” of Venus and answer not many other questions .
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