In September 2015, a new study provided an important missing piece to the intriguing puzzle of how our Moon came to be the lovely object that we see today.
Jupiter is circled by a bewitching duo of moons that are potentially capable of nurturing delicate tidbits of life as we know it. Like its more famous sister-moon, Europa, Ganymede might harbor a life-loving subsurface ocean of liquid water in contact with a rocky seafloor. This special arrangement would make possible a bubbling cauldron of fascinating chemical reactions--and these reactions could potentially include the same kind that allowed life to evolve on our own planet!
Earlier infrared data did not have sufficient resolution to separate MK 2 from Makemake's veiling glare. The astronomers' reanalysis, however, based on the more recent HST observations, indicates that much of the warmer surface spotted earlier in infrared light may simply be the dark surface of the companion MK 2.