Asteroids are rocky bodies up to about 1,000 kilometres in diameter, although most are much smaller.

小行星是岩石体，直径可以达到约1,000公里，虽然大多数小行星要小得多。

youdao

On September 26th the group announced, in a paper posted to arXiv, an online database, that its participants had discovered two probable exoplanets, one a Jupiter-like gas giant, and the other, possibly, a smaller, rocky world about twice the diameter of Earth.

ECONOMIST: Amateur astronomers join the ranks of the planet hunters