In fact, in 1995, the exoplanet 51 Pegasi b was discovered, which has half the mass of Jupiter but is 20 times closer to its star than the Earth is to the Sun.

事实上，在 1995 年， 系外行星 51 Pegasi b 被发现，它的质量是木星的一半， 但与恒星的距离是地球与太阳的 20 倍。