Is This The Largest Rocky Exoplanet That We’ve Ever Found?

Space





Photo credit:

Kepler-10c, illustrated, may have been usurped by BD+20594b. Harvard-Smithsonian Center for Astrophysics/David Aguilar

What is the upper limit on how large a rocky planet can be? This is a contentious area in astronomy. Generally, it’s thought that above about 1.6 times the radius of Earth, a planet will become a gas giant. Anything below this is a super-Earth, and smaller still are the terrestrial planets the size of Earth, Mars, and so on.