The JWST space telescope has shown that the planet GJ 3929b has no atmosphere. GJ 3929b was discovered in 2022 using TESS data. It is about the size of Earth, with a mass of ~0.43 Earth masses and a radius of ~1.15 Earth radii. Interestingly, the planet could have been a potentially habitable zone, but JWST found it simply a dark, airless rock.
The researchers found that the planet does not have a CO²-rich atmosphere. This is essential information for scientists studying how minor planets like Earth retain or lose their atmospheres in response to the radiation intensity from their stars.
