Less than a year ago, a molecule related to the activity of bacteria was postulated in Venus’ sulfur clouds. But we must be disappointed: this sister of the earth took the most inhospitable path possible.
Remember, last year: the entire scientific press reproduced the same information, and soon all the media of the world followed suit. Completely improbable news, which made us all dream: We just discovered possible evidence of life on Venus! Last September, a team of astronomers said they had observed traces of phosphine in the atmosphere of the most inhospitable of the planets. However, phosphine is an organic compound that is largely rejected on Earth by some anaerobic bacteria (which do not need oxygen). If there was phosphine at 450°C at the surface and 92 times Earth’s pressure, in the midst of sulfuric acid rain, there might be life too! If not on the ground, perhaps in its clouds, less aggressive to bacteria.
drier than the desert
Except that a team of researchers from the University of Belfast should remind us of reason: apart from the fact that the presence of this phosphine will only be certain when there is a probe on site to confirm it, Venus is still very hostile. The planet already has water molecules suspended in its clouds, but not in a concentration high enough to promote the appearance of life. Based on lab experiments and observations returned by probes, the researchers theorized what they call water activity in clouds: liquid water would have an activity of 1 and total dehydration an activity of 0. To exist, life would need water activity of at least 0.585. In the clouds of Venus, the activity of water will not be greater than 0.004, as acid balances its rare presence. It is lower than in our driest deserts! So they must conclude that the water level in the clouds of Venus is a hundred times lower than that which would be necessary to support life: even the most sensitive bacteria we know will not survive it.
So much so that even Exploring Venus using robots as we do on Mars has proven to be very difficult : In 1967, the Soviet probe Venera 4, the first human body to descend into the clouds of this planet, stopped working, and was eaten by acids, 25 km from the surface! The Russians do not disintegrate, and in 1970 they succeeded in the first landing on another planet with Venera 7, which is more resistant: he was able to work for 23 minutes. We know since then that man will never set foot on Venus.
If Venus isn’t really a good candidate for life, there are other candidates in our solar system as researcher John Halsworth points out: “We found that water conditions – with only 0.585 activity – and temperature in Jupiter’s clouds could allow microbes life to exist. It’s a very thin path , but it’s better than nothing.