Dwarf Planets
Among the dwarf planets, it is 90 percent certain that Ceres has no moons larger than 1 km in size, assuming that they would have the same albedo as Ceres itself.
Pluto has five known moons. Its largest moon Charon is more than half as large as Pluto itself, and large enough to orbit a point outside Pluto's surface. In effect, each orbits the other, forming a binary system informally referred to as a double dwarf planet. Pluto's four other moons, Nix, Hydra, S/2011 P 1, and S/2012 P 1, are far smaller and orbit the Pluto–Charon system.
Makemake has no known moons. A satellite having 1% Makemake's brightness would have been detected if it had been located at an angular distance from Makemake farther than 0.4 arcseconds (0.0001 degrees; 2 microradians).
Eris has one known moon, Dysnomia. Its radius, based on its brightness, is estimated to be 50 to 125 km.
Haumea has two moons with radii estimated around 155 km (Hiʻiaka) and 85 km (Namaka).
Read more about this topic: Minor-planet Moon
Famous quotes containing the words dwarf and/or planets:
“A dwarf who brings a standard along with him to measure his own size—take my word, is a dwarf in more articles than one.”
—Laurence Sterne (1713–1768)
“Why are all these dolls falling out of the sky?
Was there a father?
Or have the planets cut holes in their nets
and let our childhood out,
or are we the dolls themselves,
born but never fed?”
—Anne Sexton (1928–1974)