A gas linked to living beings discovered on Venus, what does that mean exactly?

Does Venus harbor life?

-

• This Monday, a team of researchers announced that they had discovered a quantity of phosphine in the clouds of Venus.

• Phosphine is a gas and a biosignature, that is, it can be correlated with the presence of living organisms.

• Olivier Sanguy, scientific mediator of the Cité de l'Espace in Toulouse, tempers the enthusiasms but nevertheless sees in this discovery an important contribution in the continuation of the search for extraterrestrial life.

At the idea of ​​a planet other than Earth containing life, Venus looked like the least credible candidate.

Pressure 90 times greater than our dear blue planet, ground temperature of over 400 degrees, atmosphere loaded with acid ... Venus has long been known for its inhospitable nature.

However, since Monday, the second planet in the solar system has returned to the race for the wildest hypotheses.

An international team led by astrobiologist Jane Greaves has announced that it has detected the signature of phosphine in the clouds of Venus.

However, this gas can potentially be produced by life forms.

So, are the little green men from Venus and not from Mars?

We take stock with Olivier Sanguy, scientific mediator of the Cité de l'Espace in Toulouse.

Concretely, what have we discovered on Venus?

Phosphine is a gas considered to be a biosignature or a biomarker because living organisms can make it.

It should nevertheless be remembered that chemical phenomena unrelated to living things can also produce them.

The team of researchers in particular tried to explain this quantity of phosphine in the clouds of Venus by non-living mechanisms: action of sunlight, volcanism, minerals ... But according to this team of researchers, all these mechanisms do not produce not enough phosphines on their own to explain that it is present in such proportions.

The question then arises of the presence of living things which could produce the missing quantity.

The presence of living remains therefore very hypothetical?

This obviously remains, and we must insist on it, a hypothesis and a huge "If".

Venus being a planet with very different conditions from those of Earth, it is quite possible to envisage that non-living phenomena unknown on Earth produce phosphine in quantity on Venus.

The planet is known for its inhospitality, it's hard to imagine life with such pressure and heat.

Certainly, in the clouds fifty kilometers from the surface, the pressure is almost similar to the earth and the temperature milder - about twenty degrees, and for decades it has been said that life could appear there, even if it remains the problem of the acidity of the atmosphere.

It is therefore a gigantic “If”, with which it is necessary to take a lot of tweezers.

What will be the next steps in the research?

We are not going to stop there.

The discovery of phosphine in quantity puts Venus back in the spotlight, while it is a planet that has tended to be a little neglected during space exploration in recent years.

Yet it is extremely interesting.

It's as if she was saying "Hi, I'm here".

There are obviously reasons for this neglect.

To explore Venus is to put yourself in appalling conditions, and even the strongest probes only lasted an hour due to the pressure, heat and acidity.

There will inevitably be more missions or questions on Venus than before, yet we must also put into perspective, it is not yet on the "podium" of the tracks of extraterrestrial life in the solar system: Mars, Titan, Enceladus (Saturn's satellites), Europe (Jupiter's satellite) are still far ahead in terms of the possibility of sheltering or having sheltered life, in addition to having an exploration potentially much less complex than Venus.

Can this discovery change things in our search for the living?

We are in the process of shifting the boundaries of living things, at the beginning we had a very limited conception of the conditions for living things: “Not too hot, not too cold, rather on the surface.

However, even on Earth, we have discovered extremophile life forms (which live in extreme conditions, for example in the abyss), which widens the field of research of the extraterrestrial life and pushes us to go to explore zones with the very different conditions than on Earth, where a very different life could be housed.

We never stop moving and pushing the limits of the possibilities of life.

However, you also have to know how to set limits and conditions, otherwise you explore absolutely everything and you get lost.

This is why planets like Mars, which in the past had almost similar conditions to Earth, will always have the priority of exploration on Venus.

Science

A gas that could be an indirect trace of life or an unknown geochemical phenomenon discovered on Venus

Science

NASA tests a space telescope that will be able to monitor exoplanets

• Interview

• Space

• Extraterrestrial

• Space conquest

• Planet