Meet Hygiea, the Smallest Dwarf Planet in Our Solar System
https://eos.org/articles/meet-hygiea-the-smallest-dwarf-planet-in-our-solar-system
Source: By Javier Barbuzano, Eos/AGU.
Excerpt: Around 2 billion years ago, two large rock bodies hit each other in the main asteroid belt, a region between the orbits of Mars and Jupiter populated by fragments of rocks of various sizes. The impactor, with a size ranging from 75 to 150 kilometers in diameter, hit a body at least 4 times larger. Astronomers have known about this impact for a long time because it created a whole family of asteroids in the main asteroid belt, formed by the celestial body Hygiea and almost 7,000 smaller asteroids that have similar orbits. Hygiea itself has been considered an asteroid since it was discovered in 1849 by Italian astronomer Annibale de Gasparis. With a diameter just over 430 kilometers, it is the fourth-largest object in the main asteroid belt. New observations obtained with the Very Large Telescope (VLT), located in Chile and operated by the European Southern Observatory, have revealed that Hygiea is also round. Determining the shape of Hygiea doesn’t have any practical implications for its orbit or behavior, but it’s enough to propel Hygiea from asteroid to dwarf planet, according to current scientific classifications. There are four conditions that solar system objects must meet to be classified as dwarf planets: They must orbit the Sun, not be a satellite orbiting another body, not be massive enough to clear their orbit from other objects, and have a round shape due to their own gravity....
Source: By Javier Barbuzano, Eos/AGU.
Excerpt: Around 2 billion years ago, two large rock bodies hit each other in the main asteroid belt, a region between the orbits of Mars and Jupiter populated by fragments of rocks of various sizes. The impactor, with a size ranging from 75 to 150 kilometers in diameter, hit a body at least 4 times larger. Astronomers have known about this impact for a long time because it created a whole family of asteroids in the main asteroid belt, formed by the celestial body Hygiea and almost 7,000 smaller asteroids that have similar orbits. Hygiea itself has been considered an asteroid since it was discovered in 1849 by Italian astronomer Annibale de Gasparis. With a diameter just over 430 kilometers, it is the fourth-largest object in the main asteroid belt. New observations obtained with the Very Large Telescope (VLT), located in Chile and operated by the European Southern Observatory, have revealed that Hygiea is also round. Determining the shape of Hygiea doesn’t have any practical implications for its orbit or behavior, but it’s enough to propel Hygiea from asteroid to dwarf planet, according to current scientific classifications. There are four conditions that solar system objects must meet to be classified as dwarf planets: They must orbit the Sun, not be a satellite orbiting another body, not be massive enough to clear their orbit from other objects, and have a round shape due to their own gravity....