Ritter (crater)
Videos
Ritter is a lunar impact crater located near the southwestern edge of Mare Tranquillitatis. Its diameter is 29.5 km. It was named after German geographer Carl Ritter and German astrophysicist August R
The crater pair Sabine (center right) and Ritter (right), from Apollo 11
Lunar Orbiter 4 image of Sabine (right of center), Ritter (left of center), and Schmidt (lower left) craters
Apollo 10 image of Ritter
Oblique view from the south from Apollo 16
Secondary crater
Videos
Secondary craters are impact craters formed by the ejecta that was thrown out of a larger crater. They sometimes form radial crater chains. In addition, secondary craters are often seen as clusters or
MESSENGER image of secondary craters surrounding a primary impact site.
From the impact that formed Copernicus (upper center, yellow), ejecta blanketed the surrounding area. Blue denotes the outline of the ejecta deposit; secondary craters and crater chains are orange.
Group of secondary craters on Mars, as seen by HiRISE
Illustration of projectile fracturing prior to primary impact to show the chronological procedure of the creation of primary and secondary impacts from projectile fractures.