Dwarf planet CeresDate: 18 August 2020 Tags: Miscellaneous
Researchers have shed new light on the dwarf planet Ceres, which lies in the asteroid belt between Mars and Jupiter and is also the largest object in that belt.
Ceres now has the status of an “ocean world”, after scientists analysed data collected by NASA’s Dawn spacecraft.
There are officially five dwarf planets in our Solar System. The most famous is Pluto, downgraded from the status of a planet in 2006.
The other four, in order of size, are Eris, Makemake, Haumea, and Ceres. The sixth claimant for a dwarf planet is Hygiea, which so far has been taken to be an asteroid.
Using observations made through the European Space Organisation’s SPHERE instrument at the Very Large Telescope (VLT), astronomers found that Hygiea may possibly be a dwarf planet since it satisfied the four criteria set by the International Astronomical Union (IAU) for a celestial body to be called a dwarf planet.
The dwarf planet was first spotted by Giuseppe Piazzi in 1801, who assumed that Ceres was the missing planet between Mars and Jupiter. It was classified as a dwarf planet in 2006 and is the first dwarf planet to be orbited by a spacecraft.
Dawn was launched in 2007 and visited Vesta and Ceres. In 2015, it went into the orbit around Ceres, and the information it collected reinforced the idea that dwarf planets could have hosted oceans over a significant part of their history.
Scientists are interested in this dwarf planet because it hosts the possibility of having water, something that many other planets do not have.
Another reason why scientists are interested in the dwarf planet Ceres is because studying it can give insights about the formation of the Solar System since it is considered to be a fossil from that time.
There are other dwarf planets and moons in our solar system where oceans exist, including the moons of Saturn and Jupiter.
A dwarf planet is a planetary-mass object that does not dominate its region of space and is not a satellite.
Criteria for Dwarf planet
A "dwarf planet" must have criteria that (a) is in orbit around the Sun (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.