Caloris Planitia is a plain within a large impact basin on Mercury, informally named Caloris, about 1,550 km (960 mi) in diameter. It is one of the largest impact basins in the Solar System. "Calor" is Latin for "heat" and the basin is so-named because the Sun is almost directly overhead every second time Mercury passes perihelion. The crater, discovered in 1974, is surrounded by the Caloris Montes, a ring of mountains approximately 2 km (1.2 mi) tall.
The geology of Mercury is the scientific study of the surface, crust, and interior of the planet Mercury. It emphasizes the composition, structure, history, and physical processes that shape the planet. It is analogous to the field of terrestrial geology. In planetary science, the term geology is used in its broadest sense to mean the study of the solid parts of planets and moons. The term incorporates aspects of geophysics, geochemistry, mineralogy, geodesy, and cartography.
The Skinakas basin is the informal name given to a structure on Mercury that appeared to be an extremely large impact basin. The limited-resolution images available showed a double-ringed structure, with the inner ring having a diameter of around 1600 km, which would have made it one of the largest impact basins in the Solar System. It appeared to be even larger than the Caloris basin on Mercury, which has been known since the Mariner 10 flybys of that planet. The part of the outer ring that was imaged appeared to correspond to a diameter of around 2300 km.
Odin Planitia is a large basin on Mercury. It was named after the Norse god Odin in 1976 by the IAU. It was first observed in detail by Mariner 10. The plain is approximately 473 kilometers in diameter.
Sobkou Planitia is a large basin on the planet Mercury. It is named after the ancient Egyptian messenger deity Sobkou. He was associated by the Egyptians with the planet Mercury.
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 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.
Beethoven is a crater at latitude 20°S, longitude 124°W on Mercury. It is 630 km in diameter and was named after Ludwig van Beethoven. It is the eleventh largest named impact crater in the Solar System and the third largest on Mercury.
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 Michelangelo quadrangle is in the southern hemisphere of the planet Mercury, where the imaged part is heavily cratered terrain that has been strongly influenced by the presence of multiring basins. At least four such basins, now nearly obliterated, have largely controlled the distribution of plains materials and structural trends in the map area. Many craters, interpreted to be of impact origin, display a spectrum of modification styles and degradation states. The interaction between basins, craters, and plains in this quadrangle provides important clues to geologic processes that have formed the morphology of the mercurian surface.
Rembrandt is a large impact crater on Mercury. With a diameter of 716 km it is the second-largest impact basin on the planet, after Caloris, and is one of the larger craters in the Solar System. It was discovered by MESSENGER during its second flyby of Mercury on October 6, 2008. The crater is 3.9 billion years old, and was created during the period of Late Heavy Bombardment. The density and size distribution of impact craters along Rembrandt's rim indicate that it is one of the youngest impact basins on Mercury.
Raditladi is a large impact crater on Mercury with a diameter of 263 km. Inside its peak ring there is a system of concentric extensional troughs (graben), which are rare surface features on Mercury. The floor of Raditladi is partially covered by relatively light smooth plains, which are thought to be a product of the effusive volcanism. The troughs may also have resulted from volcanic processes under the floor of Raditladi. The basin is relatively young, probably younger than one billion years, with only a few small impact craters on its floor and with well-preserved basin walls and peak-ring structure. It is one of 110 peak ring basins on Mercury.
Rachmaninoff is an impact crater on Mercury. This basin, first imaged in its entirety during MESSENGER's third Mercury flyby, was quickly identified as a feature of high scientific interest, because of its fresh appearance, its distinctively colored interior plains, and the extensional troughs on its floor. The morphology of Rachmaninoff is similar to that of Raditladi, which is one of the youngest impact basins on Mercury. The age of Raditladi is estimated at one billion years. Rachmaninoff appears to be only slightly older.
Picasso is a crater on Mercury. It has drawn scientific attention because of the large, arc-shaped pit crater located on the eastern side of its floor. Similar pits have been discovered on the floors of several other Mercury craters, such as Beckett and Gibran. These pits are postulated to have formed when subsurface magma subsided or drained, causing the surface to collapse into the resulting void. If this interpretation is correct, pit-floor craters such as Picasso provide evidence of shallow magmatic activity in Mercury's history.
Renoir is a crater on the planet Mercury. Its name, after the French painter Pierre-Auguste Renoir (1841–1919), was adopted by the International Astronomical Union in 1976.
Holst is a crater on Mercury. Its name was adopted by the International Astronomical Union (IAU) on April 24, 2012.
Nabokov is a crater on Mercury. Its name was adopted by the International Astronomical Union (IAU) on April 24, 2012. Nabokov is named for the Russian and American author Vladimir Nabokov.
Lennon is a crater on Mercury. Its name was adopted by the International Astronomical Union (IAU) in 2013. Lennon is named for the English singer and songwriter John Lennon.
The Lennon-Picasso Basin is an ancient (Pre-Tolstojan) impact basin on Mercury, discovered from topographic mapping of the surface by the MESSENGER spacecraft. It is approximately 1450 km in diameter and spans the region between Picasso crater on the north rim to Lennon crater on the south rim, and the crater Holst is near the center. The basin is heavily eroded by subsequent impacts and is not obvious on the surface. A topographic low is present near the center, and scarps representing a remnant of the eastern basin rim are intact. The scarps include the highest point on the planet.
