Copernicus (lunar crater)

It may have been created by debris from the breakup of the parent body of asteroid 495 Eulalia 800 million years ago.

[2] Copernicus is visible using binoculars, and is located slightly northwest of the center of the Moon's Earth-facing hemisphere.

The circular rim has a discernible hexagonal form, with a terraced inner wall and a 30 km wide, sloping rampart that descends nearly a kilometer to the surrounding mare.

There are three distinct terraces visible, and arc-shaped landslides due to slumping of the inner wall as the crater debris subsided.

In multiple locations the rays lie at glancing angles, instead of forming a true radial dispersal.

An extensive pattern of smaller secondary craters can also be observed surrounding Copernicus, a detail that was depicted in a map by Giovanni Cassini in 1680.

In 1966 the crater was photographed from an oblique angle by Lunar Orbiter 2 as one of 12 "housekeeping" pictures that were taken to advance the roll of film between possible astronaut landing sites being surveyed.

"[4] The Apollo 12 mission landed south of Copernicus on mare basalts of Oceanus Procellarum that were believed to have been in the path of one of the crater's rays, and scientists hoped cosmic ray exposure ages of soil samples would help constrain the crater age.

[citation needed] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Copernicus.