Collision with 67P, 720 million km away, marks final bid to gather closer than ever images of the ice-and-rock cluster.
The European Space Agency (ESA) has completed its Rosetta space probe mission with a landing on a comet 720 million km away, according to mission control.
Rosetta collided with the comet 67P/Churyumov-Gerasimenko after more than 12 years in space, in a final effort to gather closer-than-ever pictures of the cluster of ice and rock.
Mission controllers in the European Space Operations Centre in Darmstadt, Germany, fell silent shortly before Friday’s touchdown, before breaking into jubilant applause as the mission was confirmed over.
There were tears, hugs and cheers at mission control when Sylvain Lodiot, spacecraft operations manager, announced: "This is the end of the Rosetta mission."
Speaking to Al Jazeera from the command centre in Germany, Detlef Koschny, one of the scientists leading the mission, said: "When we touched the surface, I have to admit, I had tears in my eyes.
"I spent 22 years on this mission and it was a very special moment."
Comets are thought to contain primordial material from the planetary system’s birth, preserved in a dark-space deep freeze.
"The mission was to go to a comet, a comet that was formed during the formation of our solar system," Koschny said.
"So we went there to learn how our own solar system formed, how the Earth formed and how life came on Earth.
Rocky, cold surface
Rosetta had been programmed to touch down at a human walking pace of about 90cm per second, after a 14-hour free fall from an altitude of 19km.
It joined long-spent robot probe Philae on the galactic wanderer’s rocky, cold surface for long journey around the Sun.
Confirmation of the mission’s end came at 11:19 GMT, when the Rosetta’s signal - with a 40-minute delay - disappeared from ground controllers’ computer screens.
Mission scientists had expected Rosetta would bounce and tumble about before settling, but its final moments will forever remain a mystery as it was instructed to switch off on first impact.
In its final hours, Rosetta sent home data gathered from nearer the comet than ever before, tasting the comet’s gas, dust and plasma, and taking close-up pictures of the spot that is now its icy tomb.
Rosetta and lander probe Philae had travelled more than six billion km over 10 years to reach 67P in August 2014 .
A social media campaign and cartoon depicting the pair as intrepid space explorers, each with its "own" Twitter account, earned the mission a global following.
On Friday, the cartoon was updated with a dusty and bashed-up Rosetta lying eyes closed on the comet surface, as Earth held a placard proclaiming "Goodbye Rosetta".
"#Rosetta, is that you?" ESA said on Twitter on Philae’s behalf.
Philae was sent to the comet surface in November 2014 , bouncing several times, then gathering 60 hours of on-site data which it sent home before entering standby mode.
Rosetta stuck with the comet, hoping to spot Philae, which it finally did in September this year.
But the spaceship started running low on energy as the comet looped out on its near-seven-year orbit, further and further away from the Sun’s rays.
Instead of letting Rosetta fade away, scientists opted to end the mission on a high by taking comet measurements from up close - too close to risk under usual operating conditions.
Insights gleaned from the $1.5bn project have shown that comets crashing into an early Earth may well have brought amino acids, the building blocks of life.
Comets of 67P’s type, however, certainly did not bring water, scientists have concluded.
"Rosetta has blown it all open. It’s made us have to change our ideas of what comets are, where they came from and ... how the solar system formed and how we got to where we are today," said Matt Taylor, a scientist with the Rosetta mission.
"We have only just scratched the surface. We have decades of work to do. The spacecraft may end but the science will continue."
For flight operators, the separation was more difficult.
"They [scientists] still have the data to analyse but we don’t have the spacecraft any more," said Lodiot, who had been involved in the project for 12 years.
Comets are thought to contain the oldest, largely unchanged, matter from the birth of our solar system about 4.6 billion years ago.
Koschny, who is an expert in comets and astroids at the ESA, told Al Jazeera: "What we can say now is that the mission has been a big success.
"I mean science analysis is only starting now. We will be able to answer some of the question we have always been asking."