The Rosetta space mission and its dramatic landing on a comet 300 million miles from Earth tops this year's list of breakthrough achievements selected by the prestigious American journal Science.
Marking the high point of the European Space Agency's Rosetta mission, the Philae probe bounced onto the surface of comet 67P/Churyumov-Gerasimenko last month.
Data from both the mothership orbiter and Philae are already starting to shed new light on the formation and evolution of comets.
Science news editor Tim Appenzeller said: "Philae's landing was an amazing feat and got the world's attention. But the whole Rosetta mission is the breakthrough. It's giving scientists a ringside seat as a comet warms up, breathes and evolves."
Rosetta has already detected water, methane and hydrogen in the gas surrounding the comet.
The journal also lists nine other 2014 breakthroughs such as details of the dinosaur to bird transition, indications that young blood can help older people, new software that gets robots to cooperate and the development of Beta Cellas that allow the study of diabetes.