Scientists have discovered the exoplanet Gliese 12 b, located in the constellation Pisces, which possesses conditions suitable for life.
The research team described their finding of Gliese 12 b in a paper published on May 23 in the journal Monthly Notices of the Royal Astronomical Society. This planet is slightly smaller than Earth and comparable in size to Venus, with an estimated surface temperature of 42 degrees Celsius. This temperature is warmer than Earth’s (15 degrees Celsius) but much cooler than many other observed exoplanets, allowing for the possibility of liquid water flowing on its surface. Researchers speculate that Gliese 12 b may have an atmosphere similar to that of Earth or Venus, or it could have no atmosphere at all, or even an atmosphere unlike any previously known.
Simulation of the surface of exoplanet Gliese 12 b. (Image: NASA/JPL-Caltech/R. Hurt).
“Gliese 12 b is one of the best research targets to understand whether a planet of Earth-like size orbiting a cool star can maintain an atmosphere. This is an essential step to enhance our understanding of the potential for life on planets in the galaxy,” said Shishir Dholakia, a Ph.D. candidate at the Center for Astrophysics at the University of Southern Queensland in Australia.
One crucial factor for a planet to maintain an atmosphere is the activity level of the host star. Red dwarfs like Gliese 12 tend to exhibit magnetic activity, periodically producing intense X-ray flares. However, Gliese 12 does not exhibit such activity, increasing the likelihood that the atmosphere of Gliese 12 b remains intact.
“The original atmospheres of Earth and Venus were lost and then restored through gases emitted from volcanoes and collisions with celestial bodies in the solar system. Today, Earth supports life, but Venus does not. Since Gliese 12 b has a temperature between that of Earth and Venus, its atmosphere will help us learn more about the evolutionary journey of life on planets,” stated Larissa Palethorpe, a Ph.D. candidate at the University of Edinburgh and University College London.
The researchers discovered Gliese 12 b using observations from the Transiting Exoplanet Survey Satellite (TESS) of NASA. To date, TESS has identified over 440 exoplanets. Gliese 12 b is part of a small group of Earth-sized exoplanets with temperate conditions, close enough for detailed atmospheric studies. According to Dholakia, since Gliese 12 b receives light in a range similar to that of Earth and Venus from the Sun, it is very useful for filling the gap between these two planets in the system. Gliese 12 b could help researchers identify exoplanets with conditions similar to Earth, raising hopes for the potential existence of life on temperate planets orbiting cool stars in the Milky Way.
