Astronomers have spotted a tiny, faint moon orbiting a dwarf planet at the outer fringes of our Solar System. The little satellite was found circling around Makemake, a dwarf planet in the large region of icy bodies located beyond Neptune called the Kuiper Belt. Nicknamed MK2, the moon is thought to only be 100 miles wide, a little over one-tenth the size of its host Makemake, which is just 870-miles wide.
The moon is thought to only be 100 miles wide
MK2 was picked up by NASA's Hubble Space Telescope in April 2015. The spacecraft's Wide Field Camera 3 has a high enough resolution, able to discern faint objects located near super bright ones. That's similar to how researchers were able to spot MK2 next to Makemake, even though the moon is 1,300 times fainter than the dwarf planet. It's the same way researchers were able to discover Pluto's smaller moons in 2005, 2011, and 2012, according to NASA.
The discovery of MK2 makes Makemake fit in a bit more with other dwarf planets. Many of the largest Kuiper Belt objects are known to have moons, but Makemake, which is the third largest known object beyond Neptune, didn't seem to have one. Now that a moon has been discovered, Makemake shares even more similarities to fellow dwarf planet Pluto, NASA says, as the two bodies are both known to be covered in frozen methane.
There's still more to learn about MK2 and its relationship with its host dwarf planet. Astronomers will continue to observe the moon to find out the true shape of its orbit and how many times it circles Makemake in a given period. Studying MK2 more in depth could reveal more about the overall density of the dwarf planet system, and the moon's orbital path may hold clues as to where MK2 came from.