2008 was a year of sweeping change, as China reinvented itself for its Olympic close-up and relative newcomer Barack Obama fought his way to victory in an election that carried hefty implications for the future of science policy in the U.S. But it was also a time of frustrating stasis: The Large Hadron Collider (LHC) ground to a halt shortly after its heralded start-up and sits dormant as the year draws to a close, and the 25th anniversary of the identification of the virus that causes AIDS passed without a cure in sight.

It was a year when scientists looked out into the heavens, unraveling the secrets of planets both near and far. Others turned their gaze inward, tracing the importance of our genes in defining who we are and what our future holds or sounding the alarm on the risks a common chemical might pose to our bodies. Human tragedies, too, had their place: Soaring food prices took their toll worldwide and the investigation of the deadly 2001 anthrax attacks came to an abrupt end with the apparent suicide of a scientist believed to be behind them.

As we look toward 2009, revisit the 10 biggest science stories of 2008 in a photo slide show.