Tycho crater

The centre of the Moon's brightest rays

Tycho is a young crater in the lower part of the Moon. 108 million years ago a huge rock hit the Moon and made it. The impact splashed dust in every direction, leaving long white streaks — 'rays'. At full moon you can see them with the naked eye!

Tycho crater is 85 km wide and 4.8 km deep with a 2 km central peak. At ~108 million years it is one of the Moon's youngest large craters, so its ray system (reaching 1,500 km) has not yet darkened. The impactor was ~8 km across. The floor is covered with solidified impact melt. In 1968 the Surveyor 7 probe landed on its flank. It is named after the Danish astronomer Tycho Brahe.

Fun facts

• Tycho's rays stretch halfway across the Moon — 1,500 km!
• The impact that made Tycho happened in the age of dinosaurs.
• In the film 2001: A Space Odyssey, the mysterious monolith is found in Tycho crater.