The third-largest object known beyond Neptune, 2007 OR10, has a moon. The discovery was reported in a poster by Gábor Marton, Csaba Kiss, and Thomas Mueller at the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society (DPS/EPSC) on Monday.
January 24 was the 30th anniversary of the Voyager flyby of Uranus. Uranian moons have been on my mind ever since New Horizons sent us close-up images of Charon. On the occasion of the anniversary, Ted Stryk produced latest-and-greatest versions of the Voyager views of these worlds.
It's looking likelier that there is an undiscovered planet orbiting beyond the Kuiper belt. If it's there, it's roughly 10 times the mass of Earth (or about half the mass of Neptune), likely never gets closer to the Sun than about 100 AU, and takes more than 10,000 years to orbit the Sun.
Pluto is reluctant to give up its secrets. Last week at the American Geophysical Union meeting I attended sessions featuring results from the New Horizons mission, and most of the presentations could be summed up thusly: the data sets are terrific, but there are still a lot of Pluto features that have scientists scratching their heads.
Last week, the pile of New Horizons LORRI camera raw image releases included nine frames from a high-resolution mosaic on Charon. Together with the color MVIC view, they make a 3D global photo of Pluto's moon. Other recently released goodies include a global backlit color image of Pluto and the first image that resolves the tiny moon Styx.
Now that New Horizons is regularly sending back data, the mission is settling into a routine of releasing a set of captioned images on Thursdays, followed by raw LORRI images on Friday. The Thursday releases give us the opportunity to see lovely color data from the spacecraft's Ralph MVIC instrument. This week, the newly available color data set covered Charon.