The year of the dwarf planet is drawing toward its climax as NASA spacecraft approach Ceres and Pluto.
Ceres is almost ready for its closeup. In photos released from its first science orbit, the Queen of the Asteroid Belt shows its cratered face and, in a few of those craters, the mysterious white spots NASA scientists have been puzzling over for months.
A photo taken May 4 by NASA’s Dawn spacecraft shows the largest to be a number of differentiated white spots that some interpret to be water ice.
Mark Sykes doesn’t think so. Sykes, director and CEO of Tucson-based Planetary Science Institute, says if Ceres held that much ice it would have registered a much stronger signal with NASA’s Herschel Space Telescope.
The spots might be minerals left over from evaporated ice, said Sykes, who is a co-investigator on Dawn’s science team.
He said science team members had plenty of conjectures about Ceres when they met in Santa Monica, California, a couple of weeks ago. He’s not willing to draw any conclusions from images that represent 1.2 kilometers per pixel.
In June, the spacecraft will be three times closer and the science a little clearer, he said. “We’re still at the stage where we can let our imaginations run amok.”
Sykes, a crusader for the restoration of Pluto’s planetary status, is also excited about its July visit by NASA’s New Horizons spacecraft.
NASA released photos in the last week that show Pluto and its five known moons — Charon, Styx, Nix, Kerberos and Hydra. The tiny moons are barely visible points of light.
They were photographed by New Horizons’ long-range camera, partly as a test of its ability to see potential hazards in its path — more moons, for instance.
“I would not be at all surprised” if more moons are found, Sykes said.
New Horizons was 55 million miles from its target when the images were taken. It will close that distance in the next two months, with its closest flyby scheduled for July 14.
Pluto and its moons will come into clearer focus as the spacecraft nears.
