Brazilians Discover a Ring on Quaoar, 'Cousin' of Pluto

An international group of researchers with several Brazilian members have discovered that Quaoar, one of the large objects orbiting beyond Neptune, has a ring. The finding, published in the journal Nature, suggests that these structures must be much more common than previously thought and calls into question the understanding of the conditions that allow them to form. "This discovery reveals to us that the satellite formation process must be more complex than previously imagined and that we need to understand how Quaoar's ring can be stable so far from it, what are the effects that allow it not to become something like a moon", says Bruno Morgado, a researcher at the Federal University of Rio de Janeiro and first author of the study, which has 59 authors from 14 countries. Quaoar is one of the known large objects that reside in the so-called Kuiper belt, where Pluto, the largest of them, is also located. At an estimated 1,110 km in diameter, it is half the size of its famous "cousin". It is probably also a dwarf planet, but the International Astronomical Union does not classify it as such, because one of the conditions to earn this title is to have reached hydrostatic equilibrium (to be approximately spherical).