On Venus, there’s not any microbe poop, so there’s no life

Dissipating sulfur dioxide is not a consequence of bacteria feeding

Venus’ atmosphere shows no evidence of bacteria feeding or poop, meaning that the planet’s clouds are not a result of microbes’ life.

As reported, the biochemistry of the dense, sulfur-rich Venusian clouds was examined in a new study where researchers were searching for evidence that any hypothetical cloud-dwelling species left behind were a result of their excretion and eating.

“We’ve spent the past two years trying to explain the weird sulfur chemistry we see in the clouds of Venus”, Paul Rimmer, an atmospheric scientist at the University of Cambridge in the U.K. and a co-author of the study said.

The atmosphere of Venus has a lot of sulfur dioxide, therefore the researchers studied the chemical reactions that would occur there. Sulfur dioxide concentrations are high in the clouds that are closest to the planet’s surface, but they decrease with altitude. The sulfur dioxide was supposed to be dissipating because it was being consumed by organisms that live in clouds. However, when the simulations were run, the researchers discovered that this idea was incorrect chemically.

“If life was responsible for the sulfur dioxide levels we see on Venus, it would also break everything we know about Venus’s atmospheric chemistry”, Sean Jordan, an astronomer at the University of Cambridge and the first author of the paper said. “We wanted life to be a potential explanation, but when we ran the models, it wasn’t a viable solution”.

The simulations mimicked the metabolic processes that air microorganisms would employ to convert food sources into energy and produce waste. The findings indicated that while these bacteria could be able to extract some sulfur dioxide from the clouds, the process would likely result in the production of huge compounds that have not yet been identified.

“We looked at the sulfur-based ‘food’ available in the Venusian atmosphere, it’s not anything you or I would want to eat, but it is the main available energy source”, Jordan said. “If that food is being consumed by life, we should see evidence of that through specific chemicals being lost and gained in the atmosphere”.

The researchers said that although the study failed to produce the results they had hoped for, it provides valuable insight into the atmospheric chemistry of alien planets, and the methodology developed for this study could be used to look for life outside the solar system.

“Even if ‘our’ Venus is dead, it’s possible that Venus-like planets in other systems could host life”, said Rimmer. “We can take what we’ve learned here and apply it to exoplanetary systems, this is just the beginning”.

In particular, the researchers said, the results might guide the observations of the James Webb Space Telescope, which is set to reveal its first scientific images, as the telescope is capable of detecting such chemical fingerprints in the atmospheres of distant exoplanets.

The conflict came to an end with an 11-day strategic bombing campaign over North Vietnam.