365 days: 2014 in science

Keith Vanderlinde/NSF

The BICEP2 telescope at the South Pole may have spied gravitational waves or dust.

This year may be best remembered for how quickly scientific triumph morphed into disappointment, and even tragedy: breakthroughs in stem-cell research and cosmology were quickly discredited; commercial spaceflight faced major setbacks. Yet landing a probe on a comet, tracing humanitys origins and a concerted push to understand the brain provided reasons to celebrate.

Asian nations soared into space this year. The Indian Space Research Organisation put a mission into orbit around Mars the first agency to do so on its first try. Japan launched the Hayabusa-2 probe, its second robotic voyage to bring back samples from an asteroid. And even as Chinas lunar rover Yutu (or Jade Rabbit) stopped gathering data on the Moons surface, mission controllers took the next step in the countrys lunar exploration programme by sending a test probe around the Moon and back to Earth.

But for commercial spaceflight, it was a bad year. Virgin Galactics proposed tourism vehicle SpaceShipTwo disintegrated during a test flight in California and killed one of its pilots. That came just three days after a launch-pad explosion in Virginia destroyed an uncrewed private rocket intended to take supplies to the International Space Station. The accident wiped out a number of research experiments destined for the station, whose managers are trying to step up its scientific output. Problems on the station also delayed the deployment of a flock of tiny Earth-watching satellites, nicknamed Doves, which are part of the general trend of using miniature CubeSats to collect space data.

On a bigger scale, the European Space Agency successfully launched the first in its long-awaited series of Sentinel Earth-observing satellites.

After a decade-long trip, the European Space Agencys Rosetta spacecraft arrived at comet 67P/ChuryumovGerasimenko in August and settled into orbit. Three months later, Rosetta dropped the Philae probe to 67Ps surface, in the first-ever landing on a comet. Philae relayed science data for 64hours before losing power in its shadowy, rocky landing site.

Meanwhile, a flotilla of Mars spacecraft probes from India, the United States and Europe had an unplanned close brush with comet Siding Spring, which zipped past the red planet in October at a distance of 139,500kilometres about one-third of the distance from Earth to the Moon. NASA rovers continued to trundle along on the Martian surface: Curiosity finally reached the mountain that it has been heading towards since landing in 2012, and Opportunity passed 40kilometres on its odometer, breaking a Soviet lunar rovers distance record for off-Earth driving.

The search for planets beyond the Solar System also got a huge boost. In February, the team behind the now mostly defunct Kepler spacecraft announced that it had confirmed the existence of 715extrasolar planets, the largest-ever single haul. Kepler data also revealed the first known Earth-sized exoplanet in the habitable zone of its star, a step closer to the long-sought Earth twin.

Considering that they have been dead for around 30,000 years, Neanderthals had a hell of a year. Their DNA survives in non-African human genomes, thanks to ancient interbreeding, and two teams this year catalogued humans Neanderthal heritage. Scientists learnt more about the sexual encounters between Homo neanderthalensis and early humans after analysing the two oldest Homo sapiens genomes on record from men who lived in southwest Siberia 45,000years ago and in western Russia more than 36,000years ago, respectively. The DNA revealed hitherto-unknown human groups and more precise dates for when H.sapiens coupled with Neanderthals, which probably occurred in the Middle East between 50,000 and 60,000 years ago. Radiocarbon dating of dozens of archaeological sites in Europe, meanwhile, showed that humans and Neanderthals coexisted there for much longer than was once thought up to several thousand years in some places.

More here:
365 days: 2014 in science