On October 28, 2019, Pierre Vernazza, an astronomer at the Laboratoire d’Astrophysique de Marseille in France, discovered with his research team the new dwarf planet, Hygiea, along w. 

To be exact, this new addition to the family of dwarf planets was not discovered for the first time by the researchers. For a long time, astronomers classified it as an asteroid. After the new observations made by Chile’s Very Large Telescope (VLT), however, Hygiea meets all four key requirements of dwarf planets.

According to popularmechanics, dwarf planets “must orbit the sun, must be round, can’t be a moon, and their orbital paths can’t be clear of debris like those of the planets in our solar system.” Until now, astronomers were uncertain of the second requirement, but new images prove that Hygiea is nearly spherical. 

In Hygiea's orbit around the sun, a large group of asteroids follow the dwarf panet. In comparison, an asteroid called Vesta has a huge crater from the creation of its companion asteroids. As a result, Vernazza expected to see a similar crater on Hygiea. But, there was nothing. After the investigation, Vernazza and his team currently believe that debris gathered together to form Hygiea after the collision explains the absence of a large crater. 

Presently, there is a total of five classified dwarf planets in our solar system: Eris, Makemake, Haumea, Pluto, and Ceres. Among the dwarf planets, Ceres has a diameter of 950 kilometers making it the smallest dwarf planet. If the International Astronomical Union officially classifies Hygiea as a dwarf planet, “Hygiea would unseat Ceres” according to ScienceNews.

by SangHyun Kim