Scientists say that one of the largest asteroids in the Solar system is a dwarf planet Gigeya.
Gigeya, about the size of Iowa, with a diameter of 267 miles, is the fourth largest object in the asteroid belt located between Mars and Jupiter. It was formed during a huge collision more than two billion years ago — an event that led to the creation of one of the biggest families of asteroids.
Despite the fact that Hygiea was discovered in 1849, it has never been observed with high enough resolution, to set its structure or shape of the surface. Using the very large telescope of the European southern Observatory (ESO), the researchers, led by Pierre Vernazza from the Laboratory of astrophysics of Marseille, France, have now discovered that Gigeya spherical and has a composition similar to Ceres — the dwarf planet, the largest object in the asteroid belt.
To be classified as a dwarf planet, the object must satisfy four requirements. It needs to revolve around the Sun, it should not be a Moon (that is, it revolves around the planet), and he must have no other rocky fragments. Finally, it needs to be large enough to be rounded under its own gravity.
Publishing their findings in Nature Astronomy , Vernazza and his colleagues argue that their evidence suggests that Gigeya meets all the requirements, so it should be classified as a dwarf planet. If that happens, Gigeya will be the smallest planet in the Solar system.
“Comparing the sphericity Hygeia with other objects in the Solar system, it is clear that Gigeya almost as spherical as Ceres, opening up the possibility of classification of this object as a dwarf planet,” wrote Vernazza.
Scientists estimate that the object that led to the formation of Hygeia, had a width of 46 to 93 miles. This impact destroyed the parent body of the asteroid, breaking it into thousands of pieces.
“This collision between two large bodies in the asteroid belt is unique over the last three or four billion years”, — reads the statement of the author of the study Paul Sevecek of the Astronomical Institute of Charles University, Czech Republic.
The international astronomical Union (IAU) is responsible for the reclassification of planetary bodies and their satellites. In 2006, the meeting of the MAS has led to the fact that Pluto was demoted in rank from planet to planet-dwarf, because it did not meet the criteria set forth in the definition of a planet. This statement was subjected to heavy criticism and the status of Pluto as a dwarf planet or planet, is still under discussion.
Commenting on the potential reclassification of Hygiea, Robert Massey of the Royal astronomical society of great Britain said that the move would be “absolutely reasonable”, given that Hygeia meets the criteria for a dwarf planet.