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.
For my first post on results from the Division for Planetary Sciences meeting, I'm going to tell you about Pluto's small moons: Styx, Nix, Kerberos, and Hydra, their bright colors and wacky rotation states.
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.
The New Horizons mission has formally selected its next target after Pluto: a tiny, dim, frozen world currently named 2014 MU69. The spacecraft will perform a series of four rocket firings in October and November to angle its trajectory to pass close by 2014 MU69 in early January 2019. In so doing, New Horizons will become the first flyby craft to pass by a target that was not discovered before the spacecraft launched.
It has been a difficult wait for new New Horizons images, but the wait is almost over; Alan Stern announced at today's Outer Planets Advisory Group meeting that image downlink will resume September 5. In the meantime, a few space fans are making the most of the small amount of data that has been returned to date.
The New Horizons team released one more picture from Tuesday's encounter, one of three high-resolution images from a mosaic that crossed the center of Charon's disk, and it took me a while to figure out what it reminded me of.
Today's press briefing at the Applied Physics Laboratory in California was preceded by hours of New Horizons team members cryptically dropping hints on Twitter at astonishing details in the seven images downlinked since the flyby. The images are, in fact, astonishing, as well as beautiful, surprising, and puzzling.
After a wait of more than 22 hours with no communication, New Horizons "phoned home" precisely on schedule after its flyby of Pluto. The signal was received at 00:52:37 UT | 20:52:37 ET | 17:52:37 PT. As planned, New Horizons returned no images with the Phone Home downlink. But every bit of telemetry indicated that the flyby executed successfully.
Now that I have a reasonable-resolution global color view of Pluto, I can drop it into one of my trademark scale image montages, to show you how it fits in with the rest of the similar-sized worlds in the solar system: the major moons and the biggest asteroids.