Scientists have found a planet with the potential for life

An exoplanet in its star’s Goldilocks habitable zone is now suspected to have a liquid water ocean and atmosphere.

The planet, named LHS 1140 b, is about 1.7 times the size of Earth and located about 48 light-years away.

This distant world, first discovered in 2017, has now been found to be a rocky world like our own, but with 10 to 20 percent of its mass made up of water, according to a new paper to be published in The Astrophysical Journal Letters this week (currently available on the arXiv preprint server).

“Of all the currently known temperate exoplanets, LHS 1140b could be our best bet to one day indirectly confirm liquid water on the surface of an alien world outside our solar system,” paper co-author Charles Cadieux, a PhD student at the Université de. Montreal, he said in a statement. “This would be a significant milestone in the search for potentially habitable exoplanets.”

LHS 1140 b orbits a red dwarf about 20 percent the size of our own sun and is at a specific distance from its sun that places it in the “Goldilocks,” or habitable zone. This refers to the range of distances from the star where the conditions are just right for the existence of liquid water on the planet’s surface. If a planet is too close to its star, it will be too hot, causing the water to evaporate, while if it is too far from its star, it will be too cold, causing the water to freeze.

The size and type of star greatly affects the location of the habitable zone. For example, the habitable zone is closer to a smaller, cooler star (like a red dwarf) and further away from a larger, hotter star.

Previously, astronomers weren’t sure whether LHS 1140 b was a rocky planet like Earth or a gas giant like Neptune, but they eventually discovered that the exoplanet is something called a super-Earth.

Using data collected by the James Webb Space Telescope (JWST), they found that LHS 1140b has a lower density than expected for a completely rocky world and that 10 to 20 percent of its mass may be water, meaning the planet could be an icy world with a liquid ocean beneath the ice, such as Jupiter’s moon Europa.

They also discovered that the planet has an atmosphere that may contain similar amounts of nitrogen to our own planet. The presence of this atmosphere would allow the planet to retain liquid water on the surface.

“This is the first time we’ve ever seen a hint of an atmosphere on a rocky or ice-rich exoplanet’s habitable zone. Detecting atmospheres on small, rocky worlds is a major goal of JWST, but these signals are much harder to see than for the atmospheres of giant planets,” he said in a statement co-author Ryan MacDonald, also a researcher at the Université de Montréal.

“LHS 1140 b is one of the best small exoplanets in the habitable zone capable of sustaining a thick atmosphere, and we may have just found evidence of air on this world.”

Astronomers have used models to predict that if LHS 1140b has an Earth-like atmosphere, it could consist of a planet-wide sheet of ice with a single ring of surface ocean about 2,500 miles in diameter, roughly half the size. Atlantic Ocean. According to the paper, this ocean could have a surface temperature of up to 68 degrees F.

This discovery therefore makes LHS 1140 ba a prime candidate for life beyond our world, as its potential atmosphere and liquid water could host Earth-like life.

“This is our first exciting look at the atmosphere of a super-Earth in the habitable zone. Compared to other known exoplanets in the habitable zone, such as those in the TRAPPIST-1 system, the star LHS 1140 appears to be quieter and less active,” he added. so it is significantly less challenging to separate the atmosphere of LHS 1140 b from the stellar signals due to starspots,” said MacDonald.

“Our initial JWST survey of LHS 1140 b revealed that it is possibly the best habitable zone exoplanet currently known for atmospheric characterization. While we need more JWST observations to confirm a nitrogen-rich atmosphere and search for additional gases, this is a very promising start.”

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