A comparison of the before and after images of the comet 67P/Churyumov-Gerasimenko's surface provides clue on the location of the lost Philae lander that went missing since November 12 last year. The lander was dropped by the Rosetta orbiter and fell on the shady side of the comet, where it couldn't get enough sunlight to power its battery.
The European Space Agency (ESA) hasn't had contact of Philae since November and has been working hard to find it. The mission team knew that Philae landed inside a patch of terrain but was unable to pinpoint its exact position. The scientists started comparing images of that spot in December to look for minor changes in hopes of finding the lost lander.
ESA officials released some processed images on Thursday of what could be Philae.
"In the best images we have after the landing, with the correct illumination and taken from an altitude of 20km - the lander would be in the range of two-times-three or three-times-three pixels. And this is exactly the problem: it's not very distinct. We have to assume there is some shadowing effect on the lander that will camouflage it," Stephan Ulamec, the lander manager with the German space agency, told BBC News.
The scientists found a bright spot on the comet's surface that matches the size and shape of Philae.
"This bright spot is visible on two different images taken in December 2014, clearly indicating that it is a real feature on the surface of the comet, not a detector artefact or moving foreground dust speck," Philippe Lamy, a member of the OSIRIS imager team, who worked on the images with scientists at France's Marseille Observatory (LAM) and at the Research Institute in Astrophysics and Planetology (IRAP) in Toulouse, told Nature.com.
However, ESA is playing it safe, clarifying that they are still uncertain whether that white spot is indeed Philae, even if it is sitting near the landing area. A final confirmation is expected to happen as soon as Philae wakes up when the comet passes the Sun in August.
