A rare full-color picture of the comet that's being shadowed by the European Space Agency's Rosetta spacecraft reveals that 67P/Churyumov-Gerasimenko looks ... um ... pretty much the way it looks in black-and-white photos.
"As it turns out, 67P/C-G looks dark gray, in reality almost as black as coal," Holger Sierks of the Max Planck Institute for Solar System Research said in a blog post unveiling the color image.
Sierks is the principal investigator for Rosetta's OSIRIS camera. OSIRIS can take color pictures by snapping exposures sequentially through red, green and blue filters. However, because the comet is moving with respect to the spacecraft as the pictures are taken, it's not a trivial task to align the images correctly and adjust the colors.
ESA says the picture released Friday, taken on Aug. 6 from a distance of 75 miles (120 kilometers), represents "the first meaningful color image of 67P/C-G."
Even though the comet is almost as black as coal, the color intensity has been adjusted to span the full range of shades from black to white. Scientists say the fact that there are no bluish patches shows that Churyumov-Gerasimenko is uniformly covered by dark dust, with none of its ice shining through.
As Rosetta's mission continues, scientists will continue to study the comet's surface composition — and as Churyumov-Gerasimenko nears the sun, the chances should improve for reviving the Philae lander that bounced onto the comet last month. That would widen Rosetta's scientific spectrum even further.