This month marks the 20th anniversary of the detection of the first planet spotted around a sun-like star. Here are some other wonderful planet extremes out there in our solar system.
The Controversy: Barnard’s Star
Barnard’s Star is famous less for the planets it has than for the planets it doesn’t have. Let me explain.
The star, the fourth closest to us, has been the subject of a heated back-and-forth in astronomy circles since the 1960s as to whether or not it has planets. The current answer is no. But for at least 10 years, following an official announcement by Peter van de Kamp in 1963, many people believed the answer was a resounding yes, and that Barnard’s Star had two gas giants orbiting it. Van de Kamp never gave up on his claims, but Hubble observations showed them to be impossible in the late 1990s.
But here’s the thing: Hubble didn’t rule out that Barnard’s Star could have planets. It ruled out largeplanets at certain distances from the ancient sun. It’s not out of the question that a rocky word or even a Neptune-sized ice giant could be there.
Future exoplanet surveys may answer the question once and for all … or just spur on more controversy.