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Comet Lander's Big Bounce Caught On Camera

The Rosetta spacecraft, which orbits the comet, captured this series of images of the Philae lander bounding off the surface. The present whereabouts of the lander remain unknown.

It was the first ever landing on a comet, and it was perfect.

Unfortunately, that wasn't the end of the journey for the European Space Agency's unmanned Philae lander. After touching down on Comet 67P/Churyumov–Gerasimenko, the lander bounced off the surface and flew high into space.

Newly released photos taken by the Rosetta spacecraft clearly show the lander on the rebound. Scientists know that first bounce took nearly two hours, and that the probe eventually bounded into a cliff. The enormous bounce was the result of the comet's tiny gravitational pull: Philae weighs more than 200 pounds on Earth, but on the comet, it weighs as much as a sheet of paper.


The lander's final resting spot on the comet remains a mystery, but scientists were able to get in touch and transmit data back from Philae. It had enough battery power to run its scientific instruments for approximately 60 hours after touchdown. The results were received here on Earth late on Friday night East Coast time.

Most of the teams that ran Philae's tools are are still analyzing data (and preparing it for publication). But the group running a sensor known as MUPUS has shared some early thoughts via Twitter.

MUPUS is a multipurpose sensor designed to understand the the physical properties of the comet's surface. It was equipped with a hammer designed to try and crack through the comet's crust. Those efforts appear to have failed, even after the team turned the hammer up to "desperate mode" and then broke the tool.

But even this taught them something about the comet's bizarre surface. Although the ground seems fluffy like cigar ash, it also appears to be quite hard.

In a perfect world, the lander would have fired harpoons at touchdown, securing it to the right landing site. Solar power would have allowed the lander's tools to operate for months, as the comet approached the sun. MUPUS would have cracked the surface, and scientists would have learned loads more.


That didn't happen, but most see the landing mission as a spectacular success.

"This was such a risky thing and a brave thing to do," says Jessica Sunshine, a researcher at the University of Maryland who has worked on several NASA comet missions. "The fact that they've gotten as much data that they have, you know it really is amazing."

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