A massive asteroid could be re-labeled as a dwarf planet after new analysis calculated its actual shape. According to some astronomers, the reclassification would make it the tiniest planet in the Solar System.
Hosted in the asteroid belt located between Mars and Jupiter, the object has been previously overlooked, and now, astronomers believe the asteroid Hygiea should, in fact, be labeled as a dwarf planet. There are just a few dwarf planets in our Solar System. The five labeled as dwarf planets are Pluto – even though some still consider it as the ninth planet – Ceres – located in the asteroid belt – Makemake, Eris, and Haumea.
Possible New Dwarf Planet
Hygiea is the fourth largest object lurking in the asteroid belt behind Ceres, Vesta, and Pallas; the latter two are large asteroids. Now, new imaging and data gathered by the European Southern Observatory’s SPHERE instrument attached to the Very Large Telescope have depicted Hygiea to have a spherical shape.
This is the first time researchers have been able to analyze the surface, shape, and size of Hygiea due to the high resolution captures. If it will be classified as a dwarf planet, Hygiea would become the smallest dwarf planet found in our Solar System.
To be labeled as a dwarf planet, a cosmic object must meet specific criteria: it must orbit around the Sun and must not be a Moon.
Moreover, it must not absorb everything close to its orbit and must have been shaped by its own gravity into a round or approximately round form. Hygiea fulfills quite a large number of requirements.
“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.
The new data helped scientists conclude that Hygiea‘s diameter is 267 miles across.
Is it a Dwarf Planet? Is it not?
Researchers were rather surprised by the results. Hygiea is located in a widespread asteroid group in the asteroid belt, where all the 7,000 different asteroids came from the same object that was once incredibly larger. However, Hygiea doesn’t show any indication marks. Instead, astronomers discovered two craters that do not correlate with the mark.
“Neither of these two craters could have been caused by the impact that originated the Hygiea family of asteroids whose volume is comparable to that of a 100 km-sized object. They are too small,” said Miroslav Brož, study co-author at the Astronomical Institute of Charles University in Prague, Czech Republic.
This signifies that Hygiea has a different back-story than earlier thought. Based on the data received, the scientists were able to simulate the hypothesis that Hygiea and its neighboring asteroids are the outcomes of a massive frontal collision that happened approximately two billion years ago. Hygiea assembled from the leftover fragments, and everything else became thousands of asteroids that are now located close to Hygiea.
However, without powerful telescopes like the one utilized for this research, scientists would have no way of finding these smoother details of the Solar System.
The study was published Monday in the journal Nature Astronomy.