Top Science Breakthroughs of 2014: Rosetta Tops Science Magazine's List

Science magazine and the American Association for the Advancement of Science (AAAS) named the European Space Agency's Rosetta mission as the scientific breakthrough of the year on Thursday.

"It was a genuine first in planetary science, and that doesn't happen very often," says Science's deputy news editor Robert Coontz, who is responsible for putting together the breakthroughs of the year feature. "This is the first time anybody's landed on a comet."

Coontz looked for one of two kinds of discoveries as the news team at Science and their colleagues who edit the AAAS's research journals evaluated the previous year's breakthroughs to come up with their end-of-year list: "The breakthrough should either be something that solves a problem or answers a question that scientists have been wrestling with, or something that opens the door to a lot of new research," he says. "It either brings closure or starts something big and new."

This year, the top spot went to a member of the latter group. The Rosetta mission garnered a huge amount of attention and excitement last month when the spacecraft released the lander Philae onto Comet 67P/Churyumov-Gerasimenko.

The landing didn't go quite as planned, as Philae bounced twice before settling sideways in the shadow of a cliff, where it would not get enough sun to recharge its batteries. The probe shut down 57 hours later, after gathering as much data as possible in the short period.

Nevertheless, the Rosetta mission goes far beyond the headline-grabbing Philae.

"Philae got all the spotlight, but the Rosetta mothership is going to do all the real scientific work, or most of it," says Coontz, who explains that the breakthrough was awarded to the overall mission rather than just the comet landing.

Rosetta is making the longest comet rendezvous ever, says Coontz. Having arrived in the comet's orbit in August, Rosetta will stick with it for the next year, capturing images and analyzing the materials around the comet. The work Rosetta has begun to do could help scientists understand the formation of the Earth and the origins of life on our planet.

"Comet impacts are thought to have been one of the principal means by which water was delivered to the early Earth, around 3.6 billion years ago, possibly contributing half the water in our oceans," Stanley Cowley, a professor at the University of Leicester's Department of Physics and Astronomy who has studied comets, including 67P, said in a press release issued by the British university last month. "Furthermore, the comet material is also known to contain simple organic molecules which may also have seeded Earth with the material from which life emerged."

Science has been naming a breakthrough of the year since 1996, when it chose new weapons to fight HIV as its first winner. Since then, among others, it has selected Dolly the cloned sheep (1997), the sequencing of the human genome (2000), the mathematical proof of the Poincaré conjecture (2006) and the discovery of the Higgs Boson (2012), "the last missing piece in physicists' standard model of fundamental particles and forces." Last year, the editors picked cancer immunotherapy as the year's top breakthrough.

This year's runners-up, which are not ranked in any particular order, include:

• New insight into the dinosaur-bird transition
• Research that showed blood from a young mouse could rejuvenate the muscles and brain of an old mouse
• Groups of cooperative robots that can work together without human supervision
• A new kind of computer chip that mimics the structure of the human brain
• The discovery of symbolic Indonesian cave art between 35,000 and 40,000 years old
• Expansion of the genetic alphabet by adding two new nucleotides into the DNA of bacteria in a laboratory setting

For the first time, Science also let its readers vote for their own top breakthrough out of 19 candidates selected by the editors earlier this fall. That list was whittled down to five finalists, which were then put up for a second round of voting. Rosetta came in third in the readers' poll with 17 percent of the votes, while the research that introduced another pair of letters into the genetic alphabet took first place with 34 percent, followed by research that showed blood from a young mouse could rejuvenate an older one, which took 32 percent of the vote.

"We realize that science is a continuous process and sometimes it can be a little artificial to single out achievements the way we do for Breakthrough," says Coontz. "But at the same time, recognizing scientific achievements is important.… [It's] worth taking a step back and looking back at what happened this year: What were the landmarks?"

Meanwhile, on the opposite end of the spectrum, the magazine also named the response to the Ebola epidemic as the "Breakdown of the Year."

"This Ebola epidemic was the worst one ever and could have been contained more effectively than it was," Coontz says. "It took us too long to realize what was going on. Well into spring, people thought it was a routine outbreak," he adds, explaining that it remains to be seen whether the world has dodged a bullet—or if we still have a long way to go before the Ebola threat dissipates. Either way, "a lot more people died than would have if we had a truly rapid response."

Finally, on a more optimistic note, the editors of Science pinpointed some exciting areas of research to watch in 2015, including combined immunotherapy to fight cancer, which builds on the breakthrough of 2013; solar system encounters like NASA's New Horizons mission, scheduled for a flyby of Pluto in July; research on the impact of shrinking Arctic sea ice on weather thousands of miles away; and the rebooting of the Large Hadron Collider at the European Organization for Nuclear Research, in Switzerland.