In April this year astronomers announced the discovery of a moon orbiting the dwarf planet Makemake at the edge of the Solar System, and now the team has released a paper with everything we know about this new addition to the Solar System.

The new moon, currently called MK2, orbits Makemake every 12.4 days and is at least 21,000 kilometers (13,000 miles) from the dwarf planet. The moon is small (160 kilometers or 100 miles across) and 1,300 times fainter than Makemake.

With this discovery, reported in the Astrophysical Journal Letters, all four confirmed dwarf planets in the outer Solar System have moons orbiting them. Having a moon will allow for a better understanding of Makemake, like calculating its mass, its density, and even its history.

“We can compare Makemake and its moon to other systems, and broaden our understanding of the processes that shaped the evolution of our Solar System,” said Dr Alex Parker, lead author of the paper and the SwRI astronomer credited with discovering the satellite, in a statement.

“Makemake’s moon proves that there are still wild things waiting to be discovered, even in places people have already looked.”