Astronomers discover potentially habitable exoplanet with James Webb telescope

A groundbreaking discovery has been made by an international team of astronomers, led by the Université de Montréal, regarding the potentially habitable exoplanet LHS 1140 b. This temperate exoplanet, located approximately 48 light-years away in the constellation Cetus, is believed to be a promising "super-Earth" with a potential ice or water-covered surface. This is prepared by SSP.

Initially, astronomers had speculated that LHS 1140 b might be a mini-Neptune, characterized by a gaseous composition albeit smaller size compared to Neptune. However, the team of scientists reexamined data from various advanced space telescopes, including the James Webb Space Telescope (JWST), to draw a different conclusion.

The close proximity of LHS 1140 b to its star's habitable zone intrigued researchers. Referred to as the "Goldilocks' Zone," this region allows for temperatures suitable for liquid water to exist, a key ingredient for life as we know it on Earth. Estimates following meticulous analysis revealed that LHS 1140 b is roughly 5.6 times the mass of Earth and 1.7 times its size, making it comparable to the well-known TRAPPIST-1 planets.

One of the critical questions surrounding LHS 1140 b centered on whether it was a mini-Neptune or a super-Earth, the latter allowing for the possibility of a hydrogen-rich atmosphere surrounding a global liquid ocean. The team of astronomers was granted dedicated observing time on the Webb Telescope, during which they observed transits of LHS 1140 b. Consequently, they were able to exclude the mini-Neptune scenario and provide evidence suggesting that the exoplanet is indeed a super-Earth, potentially equipped with a nitrogen-rich atmosphere.

It was discovered that LHS 1140 b is less dense than expected for a rocky planet, indicating the presence of water making up roughly 10 to 20 percent of its mass. This exciting finding implies that the exoplanet could resemble a snowball or ice planet, potentially housing a liquid ocean at the sub-stellar point.

Confirmation of its atmosphere composition and distinguishing between the snowball planet and bull's-eye ocean planet hypotheses will require further observations. The research group emphasized the importance of additional measurements with the Webb Telescope, focusing particularly on detecting carbon dioxide which could indicate habitable conditions on LHS 1140 b.

Detecting an Earth-like atmosphere on a temperate planet poses a challenge, but astronomers remain optimistic about the possibility. However, it will necessitate extensive observing time over several years. Although visibility is limited, astronomers are determined to conduct the necessary observations to confirm the presence of liquid water on the planet's surface and ascertain the unique conditions for potential habitability.