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.
GRAIL's main and extended science missions generated the highest resolution gravity field map of any celestial body. The map will provide a better scientific understanding of how our planet and other rocky planets in our Sun's family were born and later evolved.
"Impact simulations indicate that impacts into a hot, thin crust representative of the early Moon's near-side hemisphere would have produced basins with as much as twice the diameter as similar impacts into cooler crust, which is indicative of early conditions on the Moon's far-side hemisphere," noted lead study author Dr. Katarina Milijkovic in the November 7, 2013 JPL Press Release. Dr. Milijkovic is of the Institut de Physique du Globe de Paris.