A new dwarf planet may appear in the solar system

A new dwarf planet may appear in the solar system
A new dwarf planet may appear in the solar system

A European Space Agency (ESA) telescope called SPHERE helped discover that the asteroid Hygea fits all the criteria for a dwarf planet.

Hygea could become a new dwarf planet / © ESO

Hygea is the fourth largest object in the asteroid belt after Ceres, Vesta and Pallas. Now astronomers have observed it for the first time in high enough resolution to study the surface and determine the shape and size of this celestial body. Scientists have found that the asteroid has a spherical shape and every chance to take the place of Ceres as the smallest dwarf planet in the solar system.

As an object in the main asteroid belt, Hygea satisfied three of the four requirements for dwarf planets at once: it revolves around the Sun, is not a satellite, and, unlike the planet, has not cleared the vicinity of its orbit from other objects. The last requirement is that the object must have such a mass that its own gravity changes its shape to a spherical shape.

Until now, scientists have assumed that this asteroid has an irregular shape, but new observations with the Very Large Telescope have led to the conclusion that this celestial body is completely spherical. The diameter of Hygea was a little over 430 kilometers. This is more than half the size of Ceres (950 kilometers) - in the past the smallest dwarf planet.

But on the discovery of the spherical shape of the asteroid, the researchers did not calm down. To find out the origin of the celestial body, they carried out numerical simulations and concluded that the spherical shape of Hygea and the large family of asteroids in the Main Belt were probably the result of a large head-on collision of celestial bodies with a diameter of 75 to 150 kilometers.

Scientists' simulations show that this powerful impact, believed to have occurred about two billion years ago, completely destroyed the parent's body. After the remaining debris underwent many collisions with each other, they gave Hygea its circular shape, and also created thousands of asteroids around it.

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