A New Moon

A moon was discovered around the dwarf planet 2007 OR10 in these archival Hubble images. They were taken a year apart and reveal a moon orbiting the dwarf planet. Each image, taken by the Hubble Space Telescope‘s Wide Field Camera 3, shows the companion in a different position around the planet. 2007 OR10 is the third-largest known dwarf planet, after Pluto and Eris, and the largest unnamed body in the solar system. It’s located in the Kuiper Belt, a realm of icy debris left over from the solar system’s formation.

Image Credits: NASA / ESA / C. Kiss (Konkoly Observatory) / J. Stansberry (STScI)

Mk 2

MK2This Hubble image reveals the first moon discovered around the dwarf planet Makemake. The tiny moon is barely visible because it is almost lost in the glare of the brighter dwarf planet. The moon, nicknamed MK 2, is roughly 160 km across and orbits about 21,000 km from Makemake. Makemake is 1,300 times brighter than its moon. It’s also much larger at 1400 km across.

The Makemake system is more than 50 times farther than the Earth is from the Sun on the outskirts of our solar system in the Kuiper Belt.

Image Credits: NASA, ESA, A. Parker and M. Buie (Southwest Research Institute), W. Grundy (Lowell Observatory), and K. Noll (NASA GSFC)