The atmosphere of Venus and what happens beneath it still remains for astronomers, perhaps, one of the most interesting mysteries. However, an international group of scientists managed to lift the veil of secrecy: they discovered that the shape of the surface, hidden under thick and impenetrable clouds, affects the circulation of gases in the planet's atmosphere.
In the process of work, the specialists relied on the archival data of the Venus Express apparatus of the European Space Agency, which has now been taken out of service.
As the scientists said in a press release on the agency's website, looking at Venus from the outside, one can see a smooth "covering" of clouds. They lie in a thick (20 kilometers) layer between 50 and 70 kilometers above the planet's surface. It is impossible to see what is happening under them (unless, if you look in the infrared range or with the help of radars).
But the Venus Express probe has become the eyes of scientists. Near the equator of Venus, he helped to find an unusual accumulation of water vapor (there is much more of it there than in other areas).
The anomaly is located above the 4.5 thousand meters high mountain range - it lies in the area known as the Land of Aphrodite - this is the largest hill in terms of area, along with the Land of Ishtar and the Land of Lada.
Most likely, such an accumulation of water vapor is caused by the rise of moist air from the lower layers of the atmosphere up the mountains, so astronomers called the phenomenon "the fountain of Aphrodite." However, it is still unclear why the “fountain” remains “locked” in one place.
Another phenomenon was identified when scientists decided to observe the behavior of clouds above the "fountain" in the ultraviolet spectrum and track their speed. It turned out that it is in this area that clouds reflect less ultraviolet radiation compared to other zones, and the winds over the mountains of Aphrodite's Land blow almost 18% slower than in the surrounding area.
Promotional video:
According to scientists, the only explanation - and both anomalies at once - is the phenomenon of gravitational waves. They are often mistakenly confused with the currently popular gravitational waves, so let's explain the difference. Gravitational waves are physical disturbances in the atmosphere of planets, for the appearance of which gravity is responsible. They are characteristic only for planetary atmospheres and reservoirs. These waves form in the atmosphere of a planet when the air current traveling along the surface hits an obstacle.
In the region of mountains, the air flow first rises up along them, gradually increasing in amplitude, until, similar to sea waves, it "breaks" just below the upper boundary of the clouds. When such a wave "breaks", it, meeting with high-speed atmospheric winds, "slows down" them a little.
After passing through the area where there are elevations above the surface, the wind accelerates again and creates a rarefied region of space behind it, where water-rich air rises from the lower atmosphere, and behind it some still unknown material that poorly reflects ultraviolet light. This is precisely the process observed on Venus.
According to one of the study's authors, Jean-Loup Bertaux from the LATMOS Laboratory for Atmospheric and Space Research, the discovery became possible only thanks to the analysis of long-term (from 2006 to 2012) observations of Venus Expres' atmosphere and climate of the planet.
Subsequent studies by other devices will probably help to study in more detail not only the climate of Venus, but also explain the incredibly fast - in comparison with other planets - the speed of its rotation (the sister of the Earth makes a full revolution in four of our days, and one revolution around its axis in 243 earth days).
But even more scientists are now wondering what kind of ultraviolet absorbing material is rising from the lower atmosphere.
Details of the study are described in a scientific article published in the Journal of Geophysical Research.