LAUREL, Md. — Pluto is the star of the show for NASA's New Horizons mission — but its biggest moon, Charon, is a close second. The two icy worlds are sometimes characterized as the first known double dwarf planets because they orbit a common center of gravity in a complex gravitational dance.
So it's fitting that Charon is getting its day in the sun, in the form of a freshly processed picture that shows off its dark northern pole as well as what appear to be impact craters and chasms. The picture was acquired on Saturday by the piano-sized spacecraft's Long Range Reconnaissance Imager, from a distance of about 2.4 million miles (3.9 million kilometers).
One of the chasms indicated in the annotated version could be longer and deeper than the Grand Canyon, according to William McKinnon, a planetary scientist from Washington University in St. Louis.
"This is the first clear evidence of faulting and surface disruption on Charon," McKinnon, who's on New Horizons' geology and geophysics investigation team, said in a NASA news release.
The most prominent crater lies near Charon's south pole and is thought to be about 60 miles (96 kilometers) wide. Light-colored rays appear to extend outward, suggesting that the crater is the result of a relatively recent impact. The material in the crater's dark floor is less reflective than the ice that covers Charon's surface — except, of course, for that 200-mile-wide (320-kilometer-wide) dark area at the top.
The view should get even sharper by Tuesday, when New Horizons passes within 7,800 miles of Pluto and within 18,000 miles of Charon (12,500 and 29,000 kilometers, respectively). If these features are what they appear to be, and if the International Astronomical Union gives the OK to the New Horizons team's naming system, that dark crater could be named after Darth Vader, the Dark Lord of the Sith from the "Star Wars" saga.
Vader Crater? That's got to be the best name in the solar system. Search your feelings: You know it to be true.