The discovery of an Earth-like planet could significantly change how we look for life on other planets. Astronomers have discovered an Earth-like planet orbiting an M dwarf- they don’t have any atmosphere.
With a size slightly larger than Earth, this no-atmosphere planet- GJ 1252b- orbits its stars twice a day. As it has proximity to its star, it is believed to be intensely hot and inhospitable.
This study implies that many planets orbiting these stars may likewise lack atmospheres and, as a result, are unlikely to support life because M-dwarfs are so ubiquitous.
Michelle Hill, UC Riverside astrophysicist, and study co-author said, “The pressure from the star’s radiation is immense, enough to blow a planet’s atmosphere away.”
Astronomers observed GJ 1252b during a secondary eclipse and studied the planet’s infrared radiation to establish that it is devoid of an atmosphere. This eclipse happens when a world passes in front of a star, blocking both the light from the planet and the light reflected from the star.
The radiation revealed the planet’s sweltering daytime temperatures, which are thought to exceed 2,242 degrees Fahrenheit. This temperature is so high that it would melt gold, silver, and copper on the planet’s surface. The astronomers believed there is no atmosphere because of the heat and the alleged low surface pressure.
Stephen Kane, UCR astrophysicist and study co-author said, “Even with a tremendous amount of carbon dioxide, which traps heat, the researchers concluded GJ 1252b would still be unable to hold on to an atmosphere. The planet could have 700 times more carbon than Earth has, and it still wouldn’t have an atmosphere. It would build up initially but then taper off and erode.”
Hill said, “It’s possible this planet’s condition could be a bad sign for planets even further away from this type of star. This is something we’ll learn from the James Webb Space Telescope, which will be looking at planets like these.”
- Ian J. M. Crossfield et al. GJ 1252b: A Hot Terrestrial Super-Earth with No Atmosphere. The Astrophysical Journal Letters. DOI: 10.3847/2041-8213/ac886b