Up until now, we've only seen images of Comet 67P/Churyumov-Gerasimenko in grayscale. So we've all assumed that the comet is actually gray. However, a new photo taken by Rosetta shows the comet in its true colors: a reddish brown.
This surprised scientists because Rosetta's Alice instrument previously told us that the comet was actually black, "darker than coal."
So why have previous images shown us a grayish piece of rock? Most of the photos we've seen so far were from Rosetta's Navcam, which is working with decades-old technology. That means that the camera only takes monochrome images.
However, this new image was created using photos taken by Rosetta's OSIRIS camera, which takes images beyond visible light range. Although it can't sense color, it uses filters in front of its sensors. These images are combined and create a "true color" photo.
The image is blurry because it is a composite of images taken as OSIRIS shot the comet from different angles as Rosetta orbited it.
A Reddit user, however, used Photoshop to clean up the image, giving us this:
Of course, there is some controversy as to what "true color" really means. The color filters OSIRIS uses are not for capturing color, but for capturing scientific data. OSIRIS is mapping out the surface of the comet, so different color filters will outline specific features, as well as tell us about the comet's composition.
But we do know that Rosetta is capable of capturing color photos, and shot some beautiful color images of Mars when it flew by the planet on its journey to its target comet.
The creators of the original color Comet 67P image state that they will release higher-resolution images later this month.
The Rosetta spacecraft made history in August by becoming the first craft to orbit a comet. Last month, Rosetta's Philae Lander made history by touching down on the surface of a comet. Unfortunately, all did not go as expected, and Philae bounced several times, placing it away from its intended landing spot and in the shadow of a cliff. The shadow prevents its solar panels from receiving enough sunlight to power the lander.
However, Philae sent back scientific data before going dark, and there's hope that after a successful repositioning of its solar panels, it will wake again in the spring and continue its mission, which includes collecting samples of Comet 67P in the search for the basic building blocks and chemicals necessary for life, perhaps proving, or disproving, the theory that comets seeded life on Earth.
[Photo Credit: ESA/Rosetta]