Thursday, November 13, 2014

Philae lander sends back first ever image from comet surface

The European Space Agency’s Philae lander has sent back the first ever image from the surface of a comet.

The picture shows the cracked, bumpy surface in monochrome, with one of Philae’s three legs in the bottom left of the frame. It is not yet clear whether the leg in the image is actually touching the surface. What is certain is that Philae is not level, and may be wedged into a pit.

“We’re either looking into a ditch or we are against a wall,” said ESA Rosetta project scientist Matt Taylor.

Comets are often described as “dirty snowballs”, irregular blocks of ice covered with dust and rocks, but no human craft has ever reached the surface of one before.

Scientists re-established communications with Philae on Thursday after an anxious overnight wait while its mothership Rosetta, which relays the signals to Earth, dipped below the comet’s horizon.

Magnetic field data from Philae’s ROMAP instrument analysed overnight revealed three ‘landings’. The first was almost exactly on the expected arrival time of 15:33 GMT. But the anchoring harpoons did not fire and Philae rebounded.

In the weak gravity of the comet it took about 2 hours for the lander to return to the surface. It touched down for a second time at 17:26 GMT, then bounced again before finally coming to rest at 17:33.

ESA scientists described the lander as “stable” on Thursday morning despite concerns following the touchdown on Wednesday afternoon. It emerged that a harpoon which was meant to tether it to the surface of the 2.5 mile-wide comet had failed to deploy.

The first image from the surface is in fact a mosaic of two images taken by the lander’s CIVA (the Comet Infrared and Visible Analyser) camera. It shows one of Philae’s landing legs and the craggy surface. ESA had been expecting a view of the horizon so the scientists believe the craft is not on a flat surface.

Full article: … -from-comet-surface/

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