Mercury is the first planet from the Sun and the smallest in the Solar System. In English, it is named after the ancient Roman god Mercurius (Mercury), god of commerce and communication, and the messenger of the gods. Mercury is classified as a terrestrial planet, with roughly the same surface gravity as Mars. The surface of Mercury is heavily cratered, as a result of countless impact events that have accumulated over billions of years. Its largest crater, Caloris Planitia, has a diameter of 1,550 km (960 mi), which is about one-third the diameter of the planet. Similarly to the Earth's Moon, Mercury's surface displays an expansive rupes system generated from thrust faults and bright ray systems formed by impact event remnants.
Kuiper is a moderate-size crater with a central peak cluster located at 11.35°S 31.23°W on Mercury. It is 62 kilometers in diameter and was named after Dutch-American astronomer Gerard Kuiper in 1976. It is one of only 2 Mercurian craters which are named not after artists, and one of very few cases when the same name is used for 3 craters. Gerard Kuiper, being a leader of American planetary science, died shortly before the first images of Mercurian surface were made.
The Victoria quadrangle is a region on Mercury from 0 to 90° longitude and 20 to 70 ° latitude. It is designated the "H-2" quadrangle, and is also known as Aurora after a large albedo feature.
The Tolstoj quadrangle in the equatorial region of Mercury runs from 144 to 216° longitude and -25 to 25° latitude. It was provisionally called "Tir", but renamed after Leo Tolstoy by the International Astronomical Union in 1976. Also called Phaethontias.
Tolstoj is a large, ancient impact crater on Mercury. It was named after Leo Tolstoy by the IAU in 1976. The albedo feature Solitudo Maiae appears to be associated with this crater.
The Shakespeare quadrangle is a region of Mercury running from 90 to 180° longitude and 20 to 70° latitude. It is also called Caduceata.
The Kuiper quadrangle, located in a heavily cratered region of Mercury, includes the young, 55-km-diameter crater Kuiper, which has the highest albedo recorded on the planet, and the small crater Hun Kal, which is the principal reference point for Mercurian longitude. Impact craters and basins, their numerous secondary craters, and heavily to lightly cratered plains are the characteristic landforms of the region. At least six multiringed basins ranging from 150 km to 440 km in diameter are present. Inasmuch as multiringed basins occur widely on that part of Mercury photographed by Mariner 10, as well as on the Moon and Mars, they offer a potentially valuable basis for comparison between these planetary bodies.
The Hokusai quadrangle (H-5) is one of fifteen quadrangles on the planet Mercury. It runs from 360 to 270° longitude and 20 to 70° latitude. Named after the Hokusai crater, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Apollonia quadrangle.
The Raditladi quadrangle (H-4) is one of fifteen quadrangles on Mercury. It runs from 270 to 180° longitude and 20 to 70° latitude. Named after the Raditladi Basin, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Liguria quadrangle.
The Beethoven quadrangle is located in the equatorial region of Mercury, in the center of the area imaged by Mariner 10. Most pictures of the quadrangle were obtained at high sun angles as the Mariner 10 spacecraft receded from the planet. Geologic map units are described and classified on the basis of morphology, texture, and albedo, and they are assigned relative ages based on stratigraphic relations and on visual comparisons of the density of superposed craters. Crater ages are established by relative freshness of appearance, as indicated by topographic sharpness of their rim crests and degree of preservation of interior and exterior features such as crater floors, walls, and ejecta aprons. Generally, topography appears highly subdued because of the sun angle, and boundaries between map units are not clearly defined.
The Eminescu quadrangle (H-9) is one of fifteen quadrangles on Mercury. It runs from 216 to 288° longitude and from -25 to 25° latitude. Named after the Eminescu crater, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Solitudo Criophori quadrangle.
The Derain quadrangle (H-10) is one of fifteen quadrangles on Mercury. It runs from 288° to 360° west longitude and from 22° S to 22° N latitude. Named after the Derain crater, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Pieria quadrangle.
The Debussy quadrangle (H-14) is one of fifteen quadrangles on Mercury. It runs from 270 to 360° longitude and from -20 to -70° latitude. Named after the Debussy crater, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Cyllene quadrangle.
The Neruda quadrangle (H-13) is one of fifteen quadrangles on Mercury. It runs from 180 to 270° longitude and -20 to -70° latitude. Named after the Neruda crater, it was mapped in detail for the first time after MESSENGER entered orbit around Mercury in 2011. It had not been mapped prior to that point because it was one of the six quadrangles that was not illuminated when Mariner 10 made its flybys in 1974 and 1975. These six quadrangles continued to be known by their albedo feature names, with this one known as the Solitudo Persephones quadrangle.
Boethius is a crater on the planet Mercury. It was named after Anicius Manlius Severinus Boethius, the Roman philosopher, by the IAU in 1976. The crater was first imaged by Mariner 10 in 1974.
Raphael is a crater on Mercury. Its name was adopted by the International Astronomical Union (IAU) in 1976, and is named for the Italian painter Raphael. It is Tolstojan in age. The crater was first imaged by Mariner 10 in 1974.
Verdi is an impact crater on the planet Mercury. It was named after Italian Romantic composer Giuseppe Verdi (1813–1901) in 1979, as recognized by the International Astronomical Union. The crater's extensive ejecta blanket and secondary crater field are superposed on plains materials and older craters.
The following outline is provided as an overview of and topical guide to Mercury:
