The Oort Cloud

space · comets · solar system

Icy planetesimals. The Oort cloud is made of billions of frozen chunks of rock and ice left over from when the solar system formed billions of years ago.

Incredibly distant. It stretches from 2,000 to 200,000 AU away from the Sun, which is so far that light from the Sun would take weeks to reach there (an AU is the distance from Earth to the Sun).

Comet factory. When something nudges these icy chunks, they fall toward the Sun and become long-period comets that we can see from Earth.

Named after Jan Oort. A Dutch astronomer proposed the cloud's existence in 1950, and scientists named it after him to honor his brilliant prediction.