An Earth-like planet orbiting an M dwarf — the most common type of star in the universe — appears to have no atmosphere at all. This discovery could cause a major shift in the search for life on other planets. Illustration of the atmosphere being blown away from a planet by a nearby star. (NASA) Because M-dwarfs are so ubiquitous, this discovery means a large number of planets orbiting these stars may also lack atmospheres and therefore are unlikely to harbor living things.
The work that led to the revelations about the no-atmosphere planet, named GJ 1252b, are detailed in The Astrophysical Journal Letters.
This planet orbits its star twice during the course of a single day on Earth. It is slightly larger than Earth, and it is much closer to its star than Earth is to the sun, making GJ 1252b intensely hot as well as inhospitable.
“The pressure from the star’s radiation is immense, enough to blow a planet’s atmosphere away,” said Michelle Hill, UC Riverside astrophysicist and study co-author.
Earth also loses some of its atmosphere over time because of the sun, but volcanic emissions and other carbon cycling processes make the loss barely noticeable by helping replenish what is lost. However, in greater proximity to a star, a planet cannot keep replenishing the amount being lost.
In our solar system, this is the fate of Mercury. It does have an atmosphere, but one that is extremely thin, made up of atoms blasted off its surface by the sun. The extreme […]