Picture shows bumpy surface of 67P where Philae touched down after anxious overnight wait following gaps in communications
Philae lander ‘stable’: follow the latest developments
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 two 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.
Philae space lander sends back first image of comet landing – video
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.
“We are definitely not in the open,” said Fred Jansen, ESA Rosetta mission manager.
This presents a danger to the mission which has an initial battery life of about 60 hours. After that it must switch to rechargeable batteries and rely on solar illumination to keep it powered, so if it is stuck in a trench it may not be able to receive sunlight.
Discussions are already taking place about whether deploying the lander’s drills and other moveable parts could move it into a better position.
Four other pictures from CIVA have been downlinked. These will be released at 13:00 GMT on Thursday. They will form the first 360° panorama of the surface. The Guardian has been told by an ESA official that there may be no horizon visible in those either.
Engineers are currently investigating the best way to pinpoint the location of Philae. They are planning to use the radar instrument Consert (Comet Nucleus Sounding Experiment by Radiowave Transmission), on both Rosetta and Philae, to triangulate the position.
During the decent, Concert showed that the lander was just 50 metres adrift from the targeted landing spot. ESA had planned for an error of up to 500 metres.
Science data is flowing in, although the communications link between Philae and Rosetta remains intermittent at times.
“We have telemetry and massive data already. This is a success,” said Jansen.
The safe, if precarious, touchdown of the lander gives scientists a unique chance to ride on board a comet and study from the surface what happens as its activity ramps up as it gets closer to the sun. The £1bn ($1.58bn) Rosetta mission aims to unlock the mysteries of comets, made from ancient material that pre-dates the birth of the solar system. In the data Rosetta and Philae collect, researchers hope to learn more of how the solar system formed and how comets carried water and complex organics to the planets, preparing the stage for life on Earth.
Space agencies have sent probes to comets before, but not like this. In 1986, Nasa’s Ice mission flew through the tail of Halley’s comet. In 2005, the agency’s Deep Impact spacecraft fired a massive copper block at comet Temple 1. But none before now has landed.
The feat marks a profound success for Esa, which launched the Rosetta spacecraft more than 10 years ago from its Kourou spaceport in French Guiana. Since blasting off in March 2004, Rosetta and Philae have travelled more than 6bn kilometres to catch up with the comet, which orbits the sun at speeds up to 135,000km/h.
“We are the first to do this, and that will stay forever,” said Jean Jacques Dordain, director general of Esa.
A picture acquired by the ROLIS (ROsetta Lander Imaging System) instrument on the Philae lander, showing the comet 67P/Churyumov-Gerasimenko during Philae’s descent from a distance of approximately 3 km from the surface.
A picture acquired by the ROLIS (ROsetta Lander Imaging System) instrument on the Philae lander, showing the comet 67P/Churyumov-Gerasimenko during Philae’s descent from a distance of approximately 3 km from the surface. Photograph: European Space Agency//AFP/Getty Images