Kepler is a lunar impact crater that lies between the Oceanus Procellarum to the west and Mare Insularum in the east. To the southeast is the crater Encke. Kepler is named for the 17th century German astronomer and mathematician Johannes Kepler.
Lunar Orbiter 4 image
Kepler area in a Selenochromatic Image (Si)
Oblique view from Lunar Orbiter 3
Kepler from Apollo 12
In planetary geology, a ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to several times the diameter of their originating crater, and are often accompanied by small secondary craters formed by larger chunks of ejecta. Ray systems have been identified on the Moon, Earth, Mercury, and some moons of the outer planets. Originally it was thought that they existed only on planets or moons lacking an atmosphere, but more recently they have been identified on Mars in infrared images taken from orbit by 2001 Mars Odyssey's thermal imager.
Fresh impact crater on Mars showing a prominent ray system of ejecta. This 30 m (98 ft) diameter crater formed between July 2010 and May 2012 (19 November 2013; 3°42′N 53°24′E / 3.7°N 53.4°E / 3.7; 53.4).
Gratteri crater, a rayed crater on Mars that was imaged by THEMIS at night. Image covers an area 32 km across.
The rays of Kuiper, one of the freshest craters on Mercury
Asymmetrical ray system about the lunar crater Proclus (Apollo 15 image)
