Draconid meteor shower: NASA is assessing the risk to spacecraft posed by the upcoming 2011 Draconid meteor shower, a seven-hour storm of tiny space rocks.
US and European researchers have named the Nebulae system at the National Supercomputing Centre in Shenzhen in southern China the world's second-fastest machine, clocking in behind the US Department of Energy's Jaguar in Oak Ridge, Tennessee.
North Korea said Tuesday that it has reprocessed 8,000 nuclear fuel rods – perhaps enough to build another nuclear bomb. US officials say this was a violation of North Korea's commitments to nuclear disarmament talks.
New process could replace centrifuges but renew threat of nuclear proliferation.
Destruction of its nuclear cooling tower was important but largely symbolic.
Chinese espionage has become one of the most pervasive US counterintelligence problems, officials say.