When it first reached the ground after that, the sensors on its feet picked up and recorded its landing sound. Apparently, that short, seemingly insignificant two-second recording, which you can listen to below, is enough for the scientists to be able to deduce that the comet's surface is probably covered in centimeters of dust, hiding a hardened layer of ice dust. As you might recall, though, the lander's harpoons failed to deploy, and it bounced twice before getting to its rather unfortunate resting spot, where it collected samples and data. Some of the samples it "sniffed" from the comet turned out to be organic molecules, which contain carbon: the basis of life on Earth.
The Philae team is still hard at work trying to find its exact location using Rosetta's cameras and its radio transmitter equipment called CONSERT. Thanks to the transmitter, ESA has narrowed down Philae's location to two small patches of land, making the search a lot easier. Once the agency finds the lander, the scientists will finally be able to fully analyze the data it beamed back. They'll also be able to figure out whether they can do anything to move it farther from the shadows, so it can harness more sunlight.
[Image credit: ESA/ATG medialab (Philae lander), ESA/Rosetta/Philae/ROLIS/DLR (3D image of the comet), ESA/Rosetta/Philae/CONSERT (landing site)]