New observations reveal the asteroid Hygiea, the fourth largest in the main belt, has a nearly spherical shape and appears to meet the requirements for dwarf planet status. Image: ESO/P. Vernazza et al./MISTRAL algorithm (ONERA/CNRS)
Using the SPHERE instrument with the European Southern Observatory’s Very Large Telescope, astronomers have captured images of Hygiea, the fourth-largest asteroid, revealing it is a nearly spherical body, one of the requirements for being classified as a dwarf planet. If so, it would be the smallest in the solar system, with a diameter just over 430 kilometres (267 miles).
Hygiea also meets three other requirements for dwarf planet status: it orbits the sun, it is not a moon and it has not swept debris from the vicinity of its orbit.
“Thanks to the unique capability of the SPHERE instrument on the VLT, which is one of the most powerful imaging systems in the world, we could resolve Hygiea’s shape, which turns out to be nearly spherical,” lead researcher Pierre Vernazza from the Laboratoire d’Astrophysique de Marseille in France said in a statement. “Thanks to these images, Hygiea may be reclassified as a dwarf planet, so far the smallest in the solar system.”
Hygiea is the ...