The TRAPPIST-1 system is one of the most studied exoplanet systems in our galaxy. Up to seven planets orbit a red dwarf star just 40 light years from Earth. The system’s planets are similar in mass and size to Earth, and previous research suggests that three or four of them could maintain habitable conditions. The TRAPPIST-1 system has received a lot of attention since its discovery in 2017. At first glance, it seems like an ideal system for the search for extraterrestrial life. However, recent research findings have tempered these expectations. Scientists have concluded that life in this system is highly unlikely. Neither planet has a significant atmosphere, making life unlikely. Atmospheric evaporation is an important factor causing exoplanet sterility in this system. Initial attention focused on the TRAPPIST-1 system because of its similarities to the inner solar system. However, there was initial uncertainty about the suitability of red dwarfs to support the habitability of exoplanets. Red dwarfs are characterized by their low temperatures, so a habitable planet must be located very close to the star. Additionally, red dwarfs frequently experience solar flares, which can be dangerous for the emergence and maintenance of life on the planet. TRAPPIST 1, a classic representative of red dwarfs, suggests that the probability of life in this system is low. This study represents an important step toward understanding the atmospheric processes of the Trappist-1 planet. A team of scientists used the James Webb Space Telescope (JWST) to study the properties of the planet’s atmosphere. The results confirmed that the two planets closest to the star do not have significant atmospheres. This corresponds to the situation in our solar system, where Mercury also has no atmosphere. However, it was thought that colder, more distant planets could retain atmospheres. So the team turned to computer modeling. However, it turns out that the planets in the TRAPPIST 1 system are losing their atmospheres much faster than expected. Scientists calculated the rate of atmospheric evaporation based on observations of TRAPPIST 1 and other red dwarf stars. All planets in the solar system, including Earth, once had thick atmospheres. However, young red dwarfs are known to emit more intense radiation than the Sun, causing the planet’s atmosphere to evaporate faster. Given that TRAPPIST-1 is more than 8 billion years old, any atmosphere that might exist on an exoplanet in this system has already disappeared. Therefore, the TRAPPIST-1 system may be an uninhabitable star system consisting of “warm, dry rock” with no atmosphere. This research has important implications for understanding the possibility and distribution of extraterrestrial life. Considering that about 75% of the stars in our galaxy are red dwarfs, compared to 8% of Sun-like stars, the chances of finding life in the Milky Way are significantly lower.

source: https://arxiv.org/abs/2401.16490