Philae, Europe's comet space lander that went missing nearly two years ago after its batteries ran down, has finally been found wedged into a dark crack on Comet 67P.
The discovery was made by the European Space Agency's craft Rosetta, which came within 2.7km of the surface of the comet and used a high-resolution camera to capture the main body of the lander along with two out of three of its legs.
Philae went missing after completing a soft-landing on icy dirt-ball 67P/Churyumov-Gerasimenko in November 2014.
On landing, the probe's harpoons did not fire to keep it anchored to the surface and it bounced a number of times, before settling in the shadow of a cliff where its solar panels could not pick up enough energy to keep it going.
Patrick Martin, ESA's Rosetta mission manager, said the team had been beginning to think the lander would be lost forever.
"This remarkable discovery comes at the end of a long, painstaking search," he said. "It is incredible we have captured this at the final hour."
Cecilia Tubiana, a member of the camera team, who was the first to see the images when they were downloaded on Monday, said it was "amazing" to see such good detail. "With only a month left of the Rosetta mission, we are so happy to have finally imaged Philae," she said.
Matt Taylor, a Rosetta project scientist, said: "This wonderful news means that we now have the missing 'ground-truth' information needed to put Philae's three days of science into proper context, now that we know where that ground actually is."
Philae accompanied the Rosetta spacecraft when it was launched by scientists on March 2, 2004. It was last seen after touching down on the comet a decade later.
The probe's batteries ran out within three days, forcing it to go into hibernation. It has effectively been out of touch since then, although was revived briefly in June and July 2015 as the comet moved closer to the sun. Its exact location has not been known until today.
Philae has completely run out of fuel and is too far away from the Sun to get any more solar power. Scientists will now hope to crash Rosetta nearby as part of a final one-way mission to investigate the comet.
What is it?
A landing craft released from mother ship Rosetta
What was its mission?
To land on comets, study them and send the data back to the mother ship
Why "Rosetta and Philae"?
Just as the Philae obelisk and Rosetta stone were used to unlock the secrets of Egyptian hieroglyphics, this project hopes to unlock the mysteries of the solar system
When did it launch?
March 2, 2004, taking 10 years to reach Comet 67P
Why did it take so long?
The comet is nearly 800 million km away and travels so fast it can only be reached by spacecrafts using the gravitational pull of Earth and Mars to act as a slingshot
Where is Philae now?
On Comet 67P, a 4km-wide mass of frozen dust and gas
Why did it "fall asleep"?
It landed in the shadow of a cliff, where its solar panels could not provide energy
Did scientists expect it to wake up?
They hoped it would, after the comet's southern hemisphere was exposed to the Sun again
Who is running the project?
The European Space Agency