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Place Names on Mercury

In 1974 and 1975 NASA's Mariner 10 mission completed three flybys of the planet Mercury. Until then no one had more than vague impressions as to what the surface of the planet would be like since Earth based observations are inherently difficult to make for the Moon sized planet that never strays more than 28 degrees in our sky from the sun. During the life of Mariner 10, about 1000 photographs of Mercury were taken, revealing a surface riddled with craters and other interesting geological features. These pictures remain the best source of information available for study of Mercury to date.

For ease in making reference to a location or region of the planet, Mercury has been divided into fifteen quadrangles and some large and distinguishing features have been named. Quadrangles are separated and numbered according to location, starting with H-1 at the north geographic pole and ending with H-15 at the south geographic pole. Similar systems are used for each planet and moon with named features, thus the H, which stands for Hermes, helps to distinguish Mercury from other planetary and lunar bodies. Only about half of Mercury was imaged from the Mariner 10 flybys and thus the mosaicked images below are not of consecutive regions, but display only the quadrangles for which images presently exist.

Features on the surface of any planetary or lunar body in the solar system are named in compliance with the rules and conventions set by the International Astronomical Union (IAU). Unique themes are set for each type of feature on individual planets or moons to which a name must adhere when at all possible. On Mercury craters are named after famous artists, painters, authors, and musicians who have been deceased for at least three years; planitiae are called after different names for Mercury (referring to either the planet or the god) in other languages; rupes are named for ships of discovery or scientific expeditions; valles are named after radio telescope facilities; and the only montes known on the planet are named Caloris, from the Latin word for "hot". For more detailed information on how features are named visit the USGS web site at http://planetarynames.wr.usgs.gov.

Click on a thumbnail below to view a full sized  image of that quadrangle and its labeled features (TIFF format).

Quadrangle Name Number Quadrangle Coordinates File Size
H-1 Lat: 70 to 90
Long: 0 to 360
4.68 Mb
H-2 Lat: 25 to 70
Long: 0 to 90
1.73 Mb
H-3* Lat: 25 to 70
Long: 90 to 180
1.73 Mb
H-6 Lat: -25 to 25
Long: 0 to 72
1.48 Mb
(Solitudo Lycaonis)
H-7 Lat: -25 to 25
Long: 72 to 144
1.48 Mb
H-8 Lat: -25 to 25
Long: 144 to 216
1.48 Mb
(Solitudo Hermae Trismegisti)
H-11 Lat: -70 to -25
Long: 0 to 90
1.73 Mb
(Solitudo Promethei)
 H-12 Lat: -70 to -25
Long: 90 to 180
1.87 Mb
H-15 Lat: -70 to -90
Long: 0 to 360
4.69 Mb
This image is not strictly a quadrangle, but rather a mosaic highlighting
the Caloris Basin, a 1,300 kilometer diameter impact crater site.
3.16 Mb

*Two quadrangles, H-4 (Liguria) and H-13 (Solitudo Persephones), only had about 10 degrees imaged each (180 to 190 degrees longitude) and are included here in the same image as an adjacent quadrangle. Therefore H-4 can be seen as the leftmost 10 degrees on the H-3 image and H-13 can likewise be viewed as the leftmost 10 degrees on the H-12 image.

Information for this site was obtained from the USGS web site at http://planetarynames.wr.usgs.gov and from Mercury: The Elusive Planet by Robert G. Strom, Smithsonian Institution Press, Washington D.C., 1987.

Last updated July 9, 2002.

Space Exploration Resources ~ School of Earth and Space Exploration ~ Arizona State University