Rosetta is "the sexiest space mission there's ever been," according to one of the European Space Agency's scientists.
"The science is shaping up wonderfully," Rosetta project scientist Matt Taylor said.
More top news
President Barack Obama recorded a video urging for more to be done to protect the landscape from the effects of climate change.
David Cameron is facing growing pressure for the UK to take in more of the many thousands of migrants fleeing to Europe.
China has put on its biggest display of military might in a parade to commemorate victory over Japan in World War Two.