What is S/2015 (136472) 1?
S/2015 (136472) 1 is the only known moon of Makemake, a dwarf planet in the Kuiper belt. It is also nicknamed MK 2 by the team that discovered it.
Questions about S/2015 (136472) 1
Short answers, pulled from the story.
When was S/2015 (136472) 1 discovered?
Observations that led to the discovery of S/2015 (136472) 1 took place in April 2015 using the Hubble Space Telescope's Wide Field Camera 3. The discovery was announced on the 26th of April 2016.
How big is S/2015 (136472) 1?
S/2015 (136472) 1 is estimated to be between 175 and 250 km in diameter, with 175 km the most likely figure at a geometric albedo of 4%. If it shares Makemake's density, it would contribute less than 0.2% of the total system mass.
Why is S/2015 (136472) 1 so dark?
S/2015 (136472) 1 has a geometric albedo of only between 2 and 4 percent, as dark as charcoal, compared to Makemake's albedo of 82%. One explanation is that its gravity is too weak to hold onto bright volatile ices as they sublimate off its surface.
How long does S/2015 (136472) 1 take to orbit Makemake?
S/2015 (136472) 1 orbits Makemake once every 18 days at a distance of 22250 km, following a likely circular, edge-on orbit.
Does S/2015 (136472) 1 have an official name?
S/2015 (136472) 1 has no official name; it is currently known only by its provisional designation. A permanent name may eventually be drawn from a figure in the mythology of Easter Island.