NASA James Webb Scientist How We’ll Know If TRAPPIST-1 Is Home to Aliens

A NASA expert has said that scientists will be able to determine whether a group of nearby exoplanets are habitable by studying their possible atmospheres.

The question of whether the TRAPPIST-1 exoplanet has an atmosphere is the “most important” scientific investigation that anyone involved in the search for alien life is going to do for potentially a decade, NASA astrobiologist Sean Domagal-Goldman told Polygon. . newsweek,

Despite decades of scanning the sky for radio signals and an ever-growing list of exoplanets—the name given to planets orbiting other stars—scientists have never found evidence that life exists anywhere but Earth. . If this happens, the consequences of science, philosophy and religion could be profound.

An artist’s impression of the TRAPPIST-1 exoplanet TRAPPIST-1f released by NASA in February 2017. The TRAPPIST-1 exoplanet is being studied by the James Webb Space Telescope.


The TRAPPIST-1 star system is a collection of at least seven exoplanets orbiting a dwarf star about 40 light-years from Earth that is thought to be the leading candidate for potentially habitable worlds – and perhaps even life.

While preliminary investigations have shown that the planets are rocky and possibly temperate, the main question of whether they have atmospheres is impossible to glean from previous technology.

Earlier in December, the James Webb Space Telescope (JWST) was launched as NASA’s most powerful space telescope ever. Looking out into the universe with a vast array of mirrors to help capture as much light as possible, Webb has already taken the deepest infrared image ever taken of the universe.

For several weeks, its sights have been trained on TRAPPIST-1 as a priority. The important thing the telescope is looking for is any traces of the atmosphere around the planets.

“The thing that I think is universally interesting to everyone is whether or not these planets have atmospheres,” Domagal-Goldman said. “This is critical to its ability to stay. The Moon receives the same amount of energy from the Sun as Earth does, but it does not hold its atmosphere and therefore has no oceans and no global biosphere.”

In contrast, TRAPPIST worlds are large enough to hold onto their atmospheres because more mass means more gravity. However, the unknown factor is whether the star near them, TRAPPIST-1, has been violent enough to cause these atmospheres to explode over time due to outbursts of high-energy radiation.

“So this is a first command to answer for the habitability of these worlds: whether they have an atmosphere or not. It turns out that Webb is also the smoothest thing we can see,” Domagal-Goldman said.

Trappist-1 Illustration
Exoplanets are of interest to scientists because they are considered rocky and potentially habitable worlds. Above, an artist’s impression of the TRAPPIST-1 system in space, released by NASA.

material of life

Once an atmosphere is detected on any of the Trappist worlds, the answer to the next question will be: What are they made of? This would change scientists’ line of question as to whether these planets have the potential to host life, whether or not they host life.

It gets more complicated, involving in-depth measurements of the planets through a technique called transit spectroscopy.

Essentially, scientists will use Webb to capture the light from TRAPPIST-1 whenever it passes through the TRAPPIST exoplanet’s atmosphere. If this light encounters any gas such as oxygen, carbon dioxide, water vapor, or methane, it will leave a telltale trail in the starlight that Webb can detect.

“If you want to look at the kinds of biosignatures we have on Earth, that’s called oxygen and ozone from plants and algae, that’s a great biosignature because if you look at it, it’s supposed to be produced by non-biological processes. less likely,” Domagal-Goldman said.

One problem with this is that if a planet has a high amount of oxygen gas and ozone in its atmosphere.ozone There is atmospheric oxygen but with three oxygen atoms instead of two) The risk is that both of them will be “locked under the cloud deck” making them harder to observe.

“If we’re talking about a habitable planet producing a lot of oxygen, we’re talking about a global ocean, and you’ll have a hydrological cycle and cloud decks. If you have cloud decks, then It’s basically going to block the lower atmosphere, where all that oxygen is sitting,” Domagal-Goldman said.

Fortunately, there’s another gas that can also be a telltale sign of life: methane, a gas produced by living organisms. So much so that scientists are trying to stop cows burping so much, because methane is a strong greenhouse gas.

The presence of methane on other worlds is particularly exciting if that methane is mixed with other gases that give it out.

“If you look at methane in the context of these other gases that are dissipating methane, and you know those other gases are being replenished as well. That’s an indicator that the methane is not just there, but it is being regenerated super fast,” said Domagal-Goldman.

“If you know that methane is being rapidly depleted, it has to be replenished rapidly and that rapid replenishment is a biosignature.”

It is uncertain whether a successful discovery of the TRAPPIST-1 planets can be expected, but with an estimated 20 years ahead, Webb has plenty of time to look.

“If you had asked me eight years before the discovery of the TRAPPIST-1 world if JWST was going to do any science on this class of world, I would have said it is possible, but I would have dampened my enthusiasm. Because that would require a darn near the right telescope and darn near the right target,” Domagal-Goldman said.

“We now know that Webb is now acting perfectly close. And they were close to the right target when we found the Trappist world.”

“For the search for potentially habitable worlds, the question of whether TRAPPIST planets in the habitable zone have atmospheres is the most important scientific question or observation to be made by anyone, with JWST or any other facility. Maybe for the next five or 10 years,” he said.

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