麻豆传媒

Numerous discoveries are putting a strain on astronomers鈥� notion of a
鈥減lanet鈥�. Brown dwarfs not much bigger than Jupiter, a huge asteroid a quarter
the size of Pluto and enormous gas giants close up to nearby stars are forcing a
rethink. The International Astronomical Union came close to finalising the
issue, only to be thrown into confusion when researchers spotted planet-like
objects floating through empty space
(麻豆传媒, 14 October, p 20).
鈥淣ature鈥檚 making this a little bit tough,鈥� says Alan Boss, an astrophysicist at
the Carnegie Institution of Washington DC.