January
Flu researchers announce a temporary halt on H5N1 bird flu experiments amid ongoing controversy over whether the benefits outweigh the potential risks.
stages a 24-hour blackout in protest against two copyright bills going through the US Congress.
February
Stem cells are discovered in human ovaries, suggesting that new eggs are created throughout a woman's life. The finding could one day enhance IVF treatments.
Last year's shocking result that neutrinos apparently travelled faster than the speed of light may actually have been due to a faulty fibre-optic cable, says CERN.
March
Sabu, the world's most notorious computer hacker and leader of LulzSec, is exposed as an FBI informant.
April
Synthetic biologists discover that six other molecules, not just DNA, can store and pass on genetic information.
May
Economic crisis leaves Greece on the brink of a humanitarian disaster as savage austerity measures spark violent street protests.
June
The Stuxnet computer worm that wrecked Iran's nuclear facilities is revealed to be a US cyberweapon, launched by the Bush administration and later endorsed by President Obama.
July
Particle physics makes headline news around the world as a team at CERN announces that the Higgs boson may have been discovered. The world's most sought-after particle, which gives all elementary particles mass, was spotted by sifting through the debris of trillions of collisions between protons within the ATLAS and CMS detectors at CERN's Large Hadron Collider (see photo). The discovery comes almost 50 years after Peter Higgs predicted the boson existed.
August
NASA's rover, Curiosity, arrives on Mars in the most ambitious and complicated space landing ever made.
September
Arctic sea ice shrinks to a record low. If the decline continues, by the 2050s Arctic summers could be ice-free for the first time in 3 million years.
October
Hurricane Sandy crashes into the east coast of the US, causing widespread devastation and power cuts, and leaving huge swathes of New York under water.
Felix Baumgartner leaps from a balloon 39km above the Earth and becomes the first skydiver to break the speed of sound in free fall.
November
President Obama is re-elected after a campaign that saw micro-targeting of voters using social media. The result was predicted by statistician Nate Silver.
Europe will face more floods and higher temperatures as the effects of climate change worsen, a new report warns.
December
The first ysis of soil on Mars by the Curiosity rover reveals a mysterious carbon compound.