The Koronis family is a family of asteroids in the main belt between Mars and Jupiter. They are thought to have been formed at least two billion years ago in a catastrophic collision between two larger bodies. The largest known (208 Lacrimosa) is about 41 km (25 miles) in diameter. The Koronis family travels in a cluster along the same orbit. Over 300 have been found but only about 20 are larger than 20 km in diameter.