NASA reports cosmic milestone: over 5000 exoplanets have been discovered so far!
Among them are the most diverse celestial bodies: rocky planets like Earth, gas giants many times larger than Jupiter, “hot Jupiters” orbiting very close to their star. But also “super-Earths” – rocky planets larger than Earth – and “mini-Neptunes” – planets that resemble Neptune but are smaller – are part of the motley mix of planets now known. There are also exoplanets orbiting two stars at the same time, or orbiting the collapsed remains of a dead star!
The 5000 is “not just a number,” underlines Jessie Christiansen, an astrophysicist at Caltech’s Nasa Exoplanet Science Institute in Pasadena. “Each exoplanet is a new world, a brand new planet. I get excited about each one because we don’t know anything about them.”