'Amazing' Rosetta space probe ends its 12-year mission
Published 01/10/2016 | 02:30
Scientists will be sifting through the wealth of data and images sent back to Earth by Rosetta and its Philae lander for decades to come.
The €1.2bn mission was one of the most successful ever carried out by the European Space Agency.
The spacecraft ended its historic 12-year mission to intercept and investigate comet 67P/C-G by crashing into the rock's surface after 19km descent.
In its final few minutes the probe sent back images of dazzling detail from above the comet's surface, adding to the unprecedented store of data the endeavour has already accumulated.
Rosetta achieved what had never been attempted before - to catch up with a comet hurtling through space, circle the object as it flew towards the Sun, and land a probe on its surface. When the tiny lander Philae bounced on to comet 67P/Churyumov-Gerasimenko on November 12, 2014, before vanishing into a dark crevice, it won the mission millions of fans around the world. The aim was to shed light on the origins of the solar system and how life may have started on Earth and elsewhere. A comet is essentially a time capsule, composed of material that can be traced back to the creation of the Sun and its planets out of a cloud of dust and gas 4.6 billion years ago.
Rosetta delivered a number of surprises after finally reaching the comet on August 6, 2014, at the end of an epic 10-year journey through space.
Comets are often described as "dirty snowballs" - but 67P/C-G resembled a 4.5km-long rubber duck, consisting of two lobes joined by a thick neck. Scientists believe it acquired its odd shape after two smaller objects collided and stuck together.
Rather than being covered in ice, the comet turned out to be coated in a dark layer of dusty material.
One of the most unexpected finds was that the water ice within 67P was not the same as that in the Earth's oceans.
It was so-called "heavy" water, containing a high proportion of deuterium, a heavy isotope or atomic "strain" of hydrogen.
This was puzzling, since many experts had believed comets delivered most of the water found on Earth.
It raises the question, if water on Earth did not come from comets, how did it get there?
Rosetta also found evidence of abundant organic chemicals on the comet, lending weight to the theory that comets may have transported the raw ingredients of life to Earth.
Commenting on Rosetta's legacy, astronomer Dr Daniel Brown, from Nottingham Trent University, said: "Rosetta remains one of the most ambitious and inspiring space mission ever.
"Chasing a comet for 10 years, swinging into orbit around an object of then undefined shape, and then landing a probe on the comet can only be described in one word: amazing."