Could Life Exist in the Clouds of Venus?

Monday - March 25 2024, 09:44 UTC - 8 months ago

A new study has found that some key building blocks of life can remain stable in concentrated sulfuric acid, which is found in the clouds of Venus. This challenges the assumption that any potential life on Venus would look vastly different from life on Earth. The findings could aid in future missions to explore Venus' clouds and the possibility of extraterrestrial life.

If there is life in the solar system beyond Earth, it might be found in the clouds of Venus. In contrast to the planet’s blisteringly inhospitable surface, Venus’ cloud layer, which extends from 30 to 40 miles above the surface, hosts milder temperatures that could support some extreme forms of life.If it’s out there, scientists have assumed that any Venusian cloud inhabitant would look very different from life forms on Earth .

That’s because the clouds themselves are made from highly toxic droplets of sulfuric acid — an intensely corrosive chemical that is known to dissolve metals and destroy most biological molecules on Earth.But a new study by MIT researchers may challenge that assumption. Published on March 18 in the journal Astrobiology, the study reports that, in fact, some key building blocks of life can persist in solutions of concentrated sulfuric acid .

The study’s authors have found that 19 amino acids that are essential to life on Earth are stable for up to four weeks when placed in vials of sulfuric acid at concentrations similar to those in Venus’ clouds. In particular, they found that the molecular “backbone” of all 19 amino acids remained intact in sulfuric acid solutions ranging in concentration from 81 to 98 percent .

“What is absolutely surprising is that concentrated sulfuric acid is not a solvent that is universally hostile to organic chemistry,” says study co-author Janusz Petkowski, a research affiliate in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).“We are finding that building blocks of life on Earth are stable in sulfuric acid, and this is very intriguing for the idea of the possibility of life on Venus,” adds study author Sara Seager, MIT’s Class of 1941 Professor of Planetary Sciences in EAPS and a professor in the departments of Physics and of Aeronautics and Astronautics .

“It doesn’t mean that life there will be the same as here. In fact, we know it can’t be. But this work advances the notion that Venus’ clouds could support complex chemicals needed for life.”The study’s co-authors include first author Maxwell Seager, an undergraduate in the Department of Chemistry at Worcester Polytechnic Institute and Seager’s son, and William Bains, a research affiliate at MIT and a scientist at Cardiff University .

The search for life in Venus’ clouds has gained momentum in recent years, spurred in part by a controversial detection of phosphine — a molecule that is considered to be one signature of life — in the planet’s atmosphere. While that detection remains under debate, the news has reinvigorated an old question: Could Earth’s sister planet actually host life?In search of an answer, scientists are planning several missions to Venus, including the first largely privately funded mission to the planet, backed by California-based launch company Rocket Lab .

That mission, on which Seager is the science principal investigator, is slated to involve a spacecraft that will explore, among other things, whether Venus’ clouds host life.The new findings might one day help astronauts to explore Venus’ clouds in person. Chemists have long wondered whether sulfuric acid, the main component of Venus’ clouds, could break down organic molecules essential for life that might get blown up there from Earth by some cataclysmic event .

In theory, this process of chemical modification in Venus’ clouds should be so severe that it would make life impossible, the Seager group say. Now, the new study suggests the opposite — that there may be no reason to conclude that life — or some types of it — could be sustained on Earthlike planets, considering how tough such conditions might be.“We have shown that sulfuric acid is not incompatible with some kinds of life in earthlike examples of astrochemical transformation," Seager says .

“It’s not the barrier that had been assumed." .