The path followed by the James Webb Space Telescope to discover life on other planets

In his to look for extraterrestrial life forms or their signatures In distant worlds the mighty The James Webb Space Telescope NASA was founded chemical formula that could identify exoplanets high housing options.

Using JWST, scientists from the Massachusetts Institute of Technology (MIT) and the University of Birmingham they said it is the best opportunity for astronomers find liquid water and even life on other planets, is to look for the absence rather than the presence of a chemical characteristic in their atmospheres.

Scientists suggest that if the terrestrial planet has significantly less carbon dioxide in its atmosphere compared to other planets in the same system, this could be a sign of liquid water (and possibly life) on the surface of this distant planet. And they argue that this new signal, of relatively depleted carbon dioxide, is the only sign of habitability detectable with the available technology we have now.

“The holy grail of exoplanet science is looking for habitable worlds and the presence of life, but all the features that have been talked about so far are beyond the reach of the latest observatories. But now we have a way to find out if there is liquid water on another planet. And it’s something we can get to in the coming years,” said astronomer Julien de Wit, a professor of planetary sciences at MIT who co-authored a study recently published in the journal. Astronomy of nature.

consulted Infobae about this important discovery, the astronomer Claudio Martinezexplained that “terrestrial planets outside the Earth that are essentially in the region or habitable zone of the Sun Mars and Venus, which are characterized by having a lot of carbon dioxide in their atmosphere“.

“That’s the point Earth does not have it, and one of the mechanisms to capture it is the oceans which absorb it. This study suggests that the decline in carbon dioxide presupposes that there is water on the planet and that this water can support life. In short, there are too many assumptions,” explained Martínez.

And I add: “This does not mean that you find a planet with low carbon dioxide content and can immediately deduce that there is life on it. There are actually other better methods to derive this, but we don’t yet have the technology to do it at that distance. And since James Webb can detect these drops of carbon dioxide, the potential existence of an ocean can be assumed. But the reality is this ‘it’s a shot in the dark’ because it will not specifically define anything about the actual existence of life on a low-carbon planet.”

Until now, astronomers discovered more than 5580 worlds outside our solar system. With today’s telescopes, astronomers can directly measure a planet’s distance from its star and the time it takes to complete one orbit. These The measurements can help scientists infer whether a planet is in the habitable zone. However, there is no way to directly confirm whether a planet is actually habitable, meaning liquid water exists on its surface.

Throughout our solar system, scientists can detect the presence of liquid oceans tracking “sparkles”. They are flashes of sunlight that reflect off liquid surfaces.

These flashes, or mirror reflections, were observed, for example, in Titan, Saturn’s largest moon, which helped confirm this month’s Great Lakes. Likewise, later studies and even NASA missions sent to study this world have shown that oceans of methane, not water, are abundant there.

However, detecting a similar glow on distant planets is beyond the reach of current technology. But de Wit and his colleagues realized there was another habitable body close to home that might be detectable on distant worlds.

“We came up with the idea when we looked at what was happening to the terrestrial planets in our own system” says Triaud. Venus, Earth, and Mars share similarities in that all three are rocky and inhabit a relatively temperate region relative to the Sun. Earth is the only planet of the trio that currently hosts liquid water. And the team noticed another obvious difference: Earth has significantly less carbon dioxide in its atmosphere.

“We assume that these planets were formed in a similar way, and if we now see a planet with much less carbon, that element must have gone somewhere. And the only process that could remove that much carbon from the atmosphere is a strong water cycle that includes oceans of liquid water,” the expert concluded.

Earth’s oceans play an important and ongoing role in absorbing carbon dioxide. Over hundreds of millions of years, the oceans absorbed enormous amounts of carbon dioxide, nearly the same amount that persists in the atmosphere of Venus today. This planetary-scale effect caused Earth’s atmosphere to become significantly depleted of carbon dioxide compared to its planetary neighbors.

“On Earth, much of the atmospheric carbon dioxide has been trapped in seawater and solid rock over geologic time scales, helping to regulate climate and habitability over billions of years,” said study co-author Frieder Klein.

The team thought so If a similar decrease in carbon dioxide were detected on a distant planet, Compared to its neighbors, this would be a reliable signal of liquid oceans and life on their surface. “After an extensive review of the literature from many fields, from biology to chemistry and even carbon sequestration in relation to climate change, we believe that, in fact, if we do detect carbon depletion, there is a good chance that it will be a strong sign.” of liquid water and/or life,” said de Wit.

In their study, the team presents a strategy for detecting habitable planets by looking for signs of spent carbon dioxide. Such a search would work best for “pea-in-a-pod” systems in which several terrestrial planets, all roughly the same size, orbit relatively close together, much like our own Solar System. The first step proposed by the team is confirm that planets have atmospheres, simply look for the presence of carbon dioxide, which should dominate most planetary atmospheres.

“Carbon dioxide is a very strong absorber in James Webb’s infrared view and is easily detected in the atmospheres of exoplanets. AND the carbon dioxide signal can reveal the presence of exoplanet atmospheres” explains de Wit.

Once astronomers find that several planets in a system host atmospheres, they can move on to measuring their carbon dioxide content to see if one planet has significantly less than the others. If so, the planet is likely habitable, meaning it hosts significant amounts of liquid water on its surface.

Likewise, habitable conditions do not necessarily mean that a planet is inhabited. To determine whether life could actually exist, the team suggests that astronomers look for another feature in the planet’s atmosphere: ozone.

On Earth, scientists note that plants and some microbes contribute to the removal of carbon dioxide, although not as much as the oceans. However, as part of this process, life forms emit oxygen, which reacts with photons from the sun to transform itself ozone, a molecule that is much easier to detect than oxygen itself.

Scientists say that if a planet’s atmosphere shows signs of both ozone and depleted carbon dioxide, it is likely a habitable, inhabited world. “If we see ozone, there’s a good chance it’s related to carbon dioxide consumed by life. And if it’s a life, it’s a glorious life. It wouldn’t just be a few bacteria. It would be a planetary-scale biomass capable of processing and interacting with enormous amounts of carbon,” Triaud said.

The team estimates that NASA’s James Webb Space Telescope could measure carbon dioxide and possibly ozone in nearby multiplanetary systems like TRAPPIST-1, a system of 7 planets orbiting a bright star just 40 light-years from Earth.

“TRAPPIST-1 is one of the few systems where we’ve been able to do terrestrial atmospheric studies with JWST.” We now have a plan to find habitable planets. If we all work together, we will be able to make paradigm-changing discoveries in the coming years,” de Wit elaborated.