The tiny moon--which for now has been designated S/2015 (136472) 1, and playfully nicknamed MK 2, for short--is more than 1,300 times dimmer than Makemake itself. MK 2 was first spotted when it was about 13,000 miles from its dwarf planet parent, and its diameter is estimated to be about 100 miles across. Makemake is 870 miles wide, and the dwarf planet, which was discovered over a decade ago, is named for the creation deity of the Rapa Nui people of Easter Island.
Dr. Soderblom further explained to the press that the gravity signatures of the larger craters especially may shed new light into the number of impacts Earth's Moon, and other bodies in our Solar System, suffered during the asteroid-rampage that characterized the Late Heavy Bombardment.
This gigantic "King of Planets" is considered by some astronomers to be a "failed star". It is about as large as a gas giant planet can be, and still be a planet. It is composed of approximately 90% hydrogen and 10% helium, with small amounts of water, methane, ammonia, and rocky grains mixed into the brew. If any more material were added on to this immense planet, gravity would hug it tightly--while its entire radius would barely increase. A baby star can grow to be much larger than Jupiter. However, a true star harbors its own sparkling internal source of heat--and Jupiter would have to grow at least 80 times more massive for its furnace to catch fire.