Astronomers say that they have used the James Webb Space Telescope (JWST) to detect for the first time an atmosphere surrounding a rocky planet outside the Solar System1. Although this planet cannot support life as we know it, in part because it is probably covered by a magma ocean, scientists might learn something from it about the early history of Earth — which is also a rocky planet and was once molten.
Finding a gaseous envelope around an Earth-like planet is a big milestone in exoplanet research, says Sara Seager, a planetary scientist at the Massachusetts Institute of Technology in Cambridge who was not involved with the research. Earth’s thin atmosphere is crucial for sustaining life, and being able to spot atmospheres on similar terrestrial planets is an important step in the search for life beyond the Solar System.
The planet investigated by JWST, called 55 Cancri e, orbits a Sun-like star 12.6 parsecs away and is considered a super-Earth, a terrestrial planet a little bigger than Earth — in this case, with about twice Earth’s radius and more than eight times as heavy. According to a paper published today in Nature1, its atmosphere is probably rich in carbon dioxide or carbon monoxide and has a thickness that is “up to a few per cent” of the planet’s radius.
To read more, click here.