Davies is a crater on Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 located at 46°N 0°E on the fringe of Acidalia Planitia

Acidalia Planitia

Acidalia Planitia is a plain on Mars. It is located between the Tharsis volcanic province and Arabia Terra to the north of Valles Marineris, centered at...

 near Arabia Terra

Arabia Terra

Arabia Terra is a large upland region in the north of Mars in that lies mostly in the Arabia quadrangle. It is densely cratered and heavily eroded. This battered topography indicates great age, and Arabia Terra is presumed to be one of the oldest terrains on the planet...

. It is approximately 49 km in diameter.

It was named in honor of Merton Davies

Merton Davies

Merton E. Davies graduated from Stanford University in 1937 and worked for the Douglas Aircraft corporation in the 1940s. He became a pioneer of spy satellite technology as a member of RAND Corporation after it split off from Douglas in 1948...

 (1917-2001), a pioneer in the cartography of planetary bodies. An employee of the Rand Corporation, he assisted NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 in mapping Mars with colleagues Gérard de Vaucouleurs

Gérard de Vaucouleurs

-External links:* * http://nedwww.ipac.caltech.edu/level5/normal_galaxies.html-Other resources:...

 and Harold Masursky

Harold Masursky

Harold Masursky was an American geologist and astronomer.He started his career working for the US Geological Survey and later joined NASA as a senior science member. He was responsible for investigation of planetary and lunar surfaces, being interested in finding scientifically valuable landing...

 and defined the prime meridian

Prime Meridian

The Prime Meridian is the meridian at which the longitude is defined to be 0°.The Prime Meridian and its opposite the 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern and Western Hemispheres.An international...

 of Mars as passing through the crater Airy-0

Airy-0

Airy-0 is a crater on Mars whose location defines the position of the prime meridian of that planet. It is about across and lies within the larger crater Airy in the region Sinus Meridiani....

. Davies lies on the prime meridian, appropriate because Davies was principally responsible for its delineation.