Summary:
- Astronomers have discovered a very low-density "super-puff" planet orbiting a star about 212 light-years from Earth.
- This planet, known as TOI-849b, is about the size of Neptune but has only about 1/3 the mass, making it one of the least dense planets ever found.
- The origin of this unusual planet remains a mystery, as it's unclear how such a low-density planet could have formed and survived so close to its host star.