Rosetta's last image before suicide mission

The Rosetta spacecraft ended its historic £1.2bn mission by smashing into the comet it has been chasing for 12 years.

Scientists at the European Space Agency cheered and hugged one another at the point of impact with the duck-shaped Comet 67P at 12.19pm.

"Thank you Rosetta," ESA director general Jan Woerner said on Twitter.

Rosetta's British project scientist, Dr Matt Taylor, described it as a "bittersweet" moment.

Speaking from the ESA's control centre in Darmstadt, Germany, he said: "There is something about the attachment, there's something about that spacecraft being there. I will feel a sense of loss, surely."

Minutes later, the ESA tweeted the last image Rosetta took of the comet's surface before its crash-landing.

The spacecraft has observed the comet across more than 6 billion km (3.7 billion miles) of space, collecting a treasure trove of information which will keep scientists busy for decades.

The practical mission may have ended, said Dr Taylor, but the wealth of information provided by Rosetta means "the science will continue".

He said: "Rosetta's blown it all open, it's made us have to change our ideas of what comets are, where they came from, and the implications of how the solar system formed and how we got to where we are today.

"We have only just scratched the surface. We have decades of work to do on this data.

"The spacecraft may end, but the science will continue."

Rosetta completed its free-fall descent at the speed of a sedate walk, joining the probe Philae, which landed on the comet in November 2014.

Europe's most ambitious space mission marks the first time a spacecraft has orbited and landed on a comet.

Rosetta has detected complex forms of carbon not found on Earth, a building block of proteins called glycine, and for the first time phosphorus which is a key component of DNA.

Scientists say the chemical make-up supports the theory that comets smashing into the Earth billions of years ago brought the ingredients for life.

But contrary to expectations, the chemical signature of water on the comet differs to that of our oceans, suggesting comets like 67P did not fill our seas.

Flight operations director Andrea Accomazzo, working on Rosetta for nearly 20 years, confessed "of course there is a bit of sadness" after a "long, long" professional investment.

"Scientists are like children: they dream without limits. There is nothing better than making dreams of children become a reality," he said.

"This is the feeling we have. For me today is mission accomplished."

The mission in numbers:
:: 12 years, six months, 28 days: mission duration, from launch to end
:: 7.9 billion km (4.9 billion miles): distance travelled since 2004
:: 786 days: time Rosetta spent circling the comet
:: 720 million km (450 million miles): current distance of Comet 67P from Earth
:: 14 hours: the duration of Rosetta's freefall
:: €1.4bn (£1.2bn): the cost of the mission
:: 500: scientists and engineers involved in the project