Ahuna MonsGazetteer of Planetary Nomenclature – Ahuna Mons /ref> () 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 are thought to be salt, similar to the better known Cererian bright spots, and likely resulted from
cryovolcanic
A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as ''cryolava''; ...
activity from Ceres's interior. It is named after the traditional post-harvest festival '' Ahuna'' of the
Sümi Naga
The Sümis are a major Naga people, Naga ethnic group native to the Northeast India, northeast Indian state of Nagaland. They primarily inhabit the central and southern regions of Nagaland, with significant populations in the Zünheboto and D ...
people of India. In July 2018, NASA released a comparison of physical features, including Ahuna Mons, found on Ceres with similar ones present on Earth.
Discovery
The mountain was discovered on images taken by the ''Dawn'' spacecraft in orbit around Ceres in 2015. It is estimated to have an average height of about and a maximum height of about on its steepest side; it is about wide at the base.
Origin
It has been proposed that Ahuna Mons formed as a
cryovolcanic
A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as ''cryolava''; ...
dome. It is the closest cryovolcano to the Sun yet discovered. It is roughly antipodal to the largest impact basin on Ceres, diameter Kerwan.
Seismic energy
A seismic wave is a mechanical wave of acoustic energy that travels through the Earth or another planetary body. It can result from an earthquake (or generally, a quake), volcanic eruption, magma movement, a large landslide and a large man- ...
from the Kerwan-forming impact may have been focused on the opposite side of Ceres, fracturing the outer layers of the area and facilitating the movement of high viscosity cryovolcanic
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...
(consisting of muddy water ice softened by its content of salts) that was then extruded onto the surface. Crater counts suggest that formation of the mountain continued into the last several hundred million years, making this a relatively young geological feature.
Ahuna Mons is associated with a positive mass anomaly, or
mascon
In astronomy, astrophysics and geophysics, a mass concentration (or mascon) is a region of a planet's or moon's crust that contains a large positive gravity anomaly. In general, the word "mascon" can be used as a noun to refer to an excess distr ...
, centered about below it, not far above the crust-mantle boundary. This suggests it was formed by a plume of mud rising from the mantle.
See also
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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. ...
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List of tallest mountains in the Solar System
This is a list of the tallest mountains in the Solar System. This list includes peaks on all celestial bodies where significant mountains have been detected. For some celestial bodies, different peaks are given across different types of measurem ...
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Wright Mons
Wright Mons is a large, roughly circular mountain and likely cryovolcano on the dwarf planet Pluto. Discovered by the ''New Horizons'' spacecraft in 2015, it is located southwest of Sputnik Planitia within List of geological features on Pluto#P ...
– A likely cryovolcanic structure discovered on the dwarf planet Pluto