WEBVTT FILE 00:00:00.000,00:00:03.070 Astronomers using the Hubble Space Telescope just discovered 00:00:03.070.00:00:07.307 a moon orbiting dwarf planet Makemake. Makemake is in a 00:00:07.307.00:00:10.878 region beyond the orbit of Neptune called the Kuiper Belt. 00:00:10.878.00:00:13.347 Several of the largest Kuiper Belt Objects are known to have 00:00:13.347.00:00:17.751 moons, and as of April 2016, that now includes Makemake, the 00:00:17.751.00:00:19.987 second brightest and third largest known object past the 00:00:19.987.00:00:23.023 orbit of Neptune. Using observations taken in 2015 with 00:00:23.023.00:00:26.326 Hubble's Wide Field Camera 3, a team of astronomers from the 00:00:26.326.00:00:28.896 Southwest Research Institute, Lowell Observatory, and NASA's 00:00:28.896.00:00:30.931 Goddard Space Flight Center estimate this moon to be 00:00:30.931.00:00:34.768 approximately 100 miles in diameter. Hubble will need to 00:00:34.768.00:00:37.204 take further observations to see exactly how frequently this moon 00:00:37.204.00:00:40.941 orbits Makemake. Astronomers hope to use this orbiting moon 00:00:40.941.00:00:43.076 to better estimate Makemake's mass, which will give us a 00:00:43.076.00:00:46.146 better idea of the dwarf planet's overall density and 00:00:46.146.00:00:49.182 thus its bulk composition. The Hubble Space Telescope has been 00:00:49.182.00:00:51.818 instrumental in the study of objects in the outer solar 00:00:51.818.00:00:54.121 system. Hubble also discovered four of the five moons orbiting 00:00:54.121.00:00:57.424 Pluto, visited by NASA's New Horizons spacecraft last July. 00:00:57.424.00:00:00.000