Airy-0

Etymology
From Airy Crater, the larger crater this smaller crater is located within, and 0&deg; of the prime meridian. Named after, a British astronomer who helped establish the Greenwich Meridian as the Prime Meridian on Earth.

Proper noun

 * 1) A crater on Mars, located within the larger Airy Crater, used as the determining landmark for the Martian prime meridian.