Kerwan () is the largest confirmed
impact basin
An impact crater is a depression in the surface of a solid astronomical body formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically h ...
and one of the largest geological features on the
dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the ...
Ceres. It was discovered on February 19, 2015 from ''
Dawn
Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the diffuse sky radiation, appearance of indirect sunlight being Rayleigh scattering, scattered in Earth's atmosphere, when the centre of the Sun's disc ha ...
'' images as it approached Ceres. The crater is distinctly shallow for its size, and lacks a central peak. A central peak might have been destroyed by a 15-kilometer-wide crater at the center of Kerwan. The crater is likely to be young relative to the rest of Ceres's surface, as Kerwan has largely obliterated the cratering in the southern part of
Vendimia Planitia.
[Marchi, S et al. “The missing large impact craters on Ceres.” Nature communications vol. 7 12257. 26 Jul. 2016, doi:10.1038/ncomms12257]
Kerwan is roughly antipodal to
Ahuna Mons
Ahuna Mons () is the largest mountain on the dwarf planet and asteroid Ceres. It protrudes above the cratered terrain, is not an impact feature, and is the only mountain of its kind on Ceres. Bright streaks run top to bottom on its slopes which ...
, the largest, or at least youngest, mountain on Ceres. Seismic energy from the Kerwan-forming impact may have focused on the opposite side of Ceres, fracturing the outer layers of the crust and facilitating the movement of high-viscosity
cryomagma (consisting of muddy water ice softened by its content of salts) onto the surface.
Kerwan too shows evidence of the effects of liquid water due to impact-melting of subsurface ice.
The crater is named after the
Hopi spirit of sprouting maize, Kerwan. The name was approved by the
IAU
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
on July 3, 2015.
[
]
See also
*List of geological features on Ceres
Ceres is a dwarf planet in the asteroid belt that lies between the orbits of Mars and Jupiter. The IAU has adopted two themes for naming surface features on Ceres: agricultural deities for craters and agricultural festivals for everything else. ...
References
{{Ceres
Impact craters on asteroids
Surface features of Ceres