A file photo released by the European Space Agency (ESA) shows an artist's impression of the Rosetta orbiter at comet 67P/Churyumov-Gerasimenko. AFP PHOTO / ESA MEDIALAB / C. CARREAU
Darmstadt, Germany: Europe was poised to send its Rosetta spacecraft on Thursday toward a crash landing on the comet it has stalked for the last two years, joining robot lander Philae on the icy dustball's surface for eternity.
The mission will conclude with a last-gasp spurt of science-gathering as Rosetta quits the orbit of comet 67P/Churyumov-Gerasimenko at about 2050 GMT to start a 14-hour, 19-kilometre (12-mile) descent.
This will all happen more than 700 million kilometres from Earth, with the comet and Rosetta zipping through space at a speed of over 14 kilometres (nine miles) per second.
"Rosetta will collect science data until the very end of its descent," said the European Space Agency's Rosetta blog.
"The opportunity to study a comet at such close proximity makes the descent phase one of the most exciting of the entire mission."
A "controlled impact" is scheduled for about 1040 GMT on Friday, with confirmation of the end of the mission expected some 40 minutes later, which is how long it takes for a signal from Rosetta to reach Earth.
After 12 years in space, Rosetta's signal will simply vanish from computer screens at mission control in Darmstadt, Germany.
The first-ever mission to orbit and land on a comet was approved in 1993 to explore the origins and evolution of our Solar System -- of which comets are thought to contain prehistoric elements preserved in a dark space deep freeze.
Rosetta and lander probe Philae blasted off in March 2004, and travelled more than six billion kilometres (3.7 billion miles) to reach 67P in August 2014.
Rosetta placed Philae on the comet's surface in November that year.
