Three New Dwarf Planets May Be Found Near Pluto. It Has Friends!
Pluto was downgraded to a dwarf planet, and everyone cried. Do not lament to hard. For not only was Pluto not the only dwarf planet when the Cosmic Canine was removed from planetary status, but now it may be getting even more friends. Discoveries abound!
io9:
Astronomers used the Warsaw Telescope at Chile’s Las Campanas Observatory to sweep the southern skies for any undiscovered large objects in the Kuiper Belt. They found fourteen such objects among the colossal conglomeration of debris. While eleven of these were simply oversized chunks, three of them appear to be big enough to meet the definition of a dwarf planet.
According to the International Astronomical Union, there are two criteria that a body must meet in order to be considered a dwarf planet. First, it must be massive enough that its gravity forces it into a spherical shape, and second, it must orbit the Sun, eliminating a number of moons that would otherwise deserve to be dwarf planets and, indeed, are actually larger than the official dwarf planets.
Currently, there are just five bodies recognized as dwarf planets: Ceres in the asteroid belt, the three in the Kuiper Belt, and Eris, the largest dwarf planet and the only one that lies beyond the Kuiper Belt. There are as many as forty additional objects in the far reaches of the solar system that might well classify for dwarf planet status, but we simply don’t have the observations yet to make an official classification.
These three latest discoveries would be found right at the lower limit of what a dwarf planet could be. They are likely only about 250 miles wide – far less than Pluto and Eris, which are both about 1,450 miles wide. If these three new objects were composed of anything other than ice, they’d likely be too small to round themselves into a spherical shape. But, as icy bodies, they likely squeak by as dwarf planet candidates.