We found our comet lander! Tipped over on its side and looking forlorn but still intact, Philae was discovered wedged into a dark crack on Comet 67P/Churyumov–Gerasimenko this weekend, less than a month before the end of the Rosetta mission.
The images were taken on Sept. 2 by the OSIRIS narrow-angle camera as the orbiter came within 1.7 miles (2.7 km) of the surface and clearly show the main body of the lander, along with two of its three legs tipped almost directly on its side. Now we can see why it was so difficult to reestablish communication with the doomed probe following the landing on Nov. 12, 2014. Not only that, but Philae rests in the shadow of an enormous sunlight-blocking boulder. Without enough sunshine for the solar panels to make electricity, there wasn’t enough power to recharge the craft’s batteries.
“With only a month left of the Rosetta mission, we are so happy to have finally imaged Philae, and to see it in such amazing detail,” says Cecilia Tubiana of the OSIRIS camera team, the first person to see the images when they were downlinked from Rosetta yesterday.
Philae was last seen when it first touched down at Agilkia, bounced and then flew for another two hours before ending up at a location later named Abydos, on the comet’s smaller lobe. Harpoons, designed to fire and anchor the craft to the comet’s surface, failed to fire, causing the probe to hit and bounce off the surface several times before setting down.
After three days, Philae’s primary battery was exhausted and the lander went into hibernation, only to wake up again and communicate briefly with Rosetta in June and July 2015 as the comet came closer to the Sun and more power was available.
Until today, mission control only known its general location. While most candidates could be discarded from analysis of the imagery and other techniques, evidence continued to build towards one particular target, which is now confirmed in images taken incredibly close to the surface of the comet.
“This remarkable discovery comes at the end of a long, painstaking search,” says
Patrick Martin, ESA’s Rosetta Mission Manager. “We were beginning to think that Philae would remain lost forever. It is incredible we have captured this at the final hour.”
Besides putting to rest questions of the lander’s whereabouts, scientists now have the missing ‘ground-truth’ information needed to put Philae’s three days of science into proper context.”We know where that ground actually is!” says Matt Taylor, ESA’s Rosetta project scientist.
The discovery comes less than a month before Rosetta descends to the comet’s surface. On 30 September, the orbiter will be sent on a final one-way mission to investigate the comet from close up, including the open pits in the Ma’at region, where it’s hoped that that photos will help to reveal secrets of the body’s interior structure. A controlled impact is set for September 30 around 10:30 UT (5:30 a.m. Central Daylight).
More information about the search for Philae along with additional images will be released soon. For now, it just feels great that Philae’s been found!
* Source: ESA