Rosetta, the comet-chasing spacecraft of the European Space Agency, has captured another self-portrait with its target comet on the background.
On Oct. 7, the CIVA (Comet Infrared and Visible Analyser) imaging system of the Philae lander onboard Rosetta captured images of the orbiter as it hovers only 10 miles from the surface of comet 67P/Churyumov-Gerasimenko.
The CIVA, which will be among the ten instruments that the Philae lander will use to closely examine 67P/C-G after it touches down on its surface, captured a similar photograph in September but it was while Rosetta was more than 30 miles away from the comet. Rosetta is nearer 67P/C-G in the latest shot so the photograph reveals more of the comet's surface features.
The European space agency said that this latest Rosetta selfie will be the last image to be taken by Philae before its scheduled descent for the surface of the comet on Nov. 12. CIVA will take the next image shortly after the lander separates from Rosetta.
"While the lander's ROLIS instrument will take images during the descent phase, CIVA will be tasked with making a 360 degree panoramic image of the landing site, including a section in stereo, once safely on the surface of 67P/C-G," ESA said in a statement.
Rosetta has also sent home other images which show a pyramid-shaped boulder protruding in the surface of the comet. Mission team members named the boulder as "Cheops" after the Great Pyramid of Giza, the largest and oldest of the three pyramids in Egypt's Giza Necropolis.
Also known as the Pyramid of Cheops, the pyramid was built around 2550 BC to be Pharaoh Cheops's tomb. The Cheops boulder in the comet, which was first seen in images taken in August, stood out among other boulders on the lower side of the comet's larger lobe but at a height of about 82 feet, it is far smaller than its namesake that rises 456 feet into the sky.
Rosetta's Optical, Spectroscopic and Infrared Remote Imaging System (OSIRIS) principal investigator Holger Sierks described Cheop's surface as "very craggy and irregular."
"Especially intriguing are small patches on the boulder's surface displaying the same brightness and texture as the underground," Sierks said. "It looks almost as if loose dust covering the surface of the comet has settled in the boulder's cracks."
Besides the size distribution of the boulders on 67P/C-G, ESA said that much of the other properties of these rocks still remain a mystery. The space agency said that scientists will look for clues on what these rocks are made of, how they were formed and how dense they are, among others, as Rosetta continues to survey its target comet.
