New evidence points to the evolution of the ability for bacteria to grab nitrogen from the atmosphere some 3.2 billion years ago, about 1.2 billion years earlier than thought—with implications for finding extraterrestrial life. Lee Billings reports

A dwarf galaxy near the Milky Way may consist of more dark matter than regular matter.* Clara Moskowitz reports

NASA has to deal with the unexpected financial consequences of robotic missions that just keep going. Lee Billings reports

The oldest group of terrestrial worlds now known formed some 11.2 billion years ago, more than six billion years before our sun and planets. Clara Moskowitz reports

New images from a NASA orbiter reveal Beagle 2’s final resting place. Lee Billings reports

Australian amateur astronomer Terry Lovejoy’s latest comet find is naked-eye visible in the southeast sky until January 24. Clara Moskowitz reports

The company hopes to send up a Falcon 9 rocket and then safely land the discarded first stage for reuse. Lee Billings reports

John Grunsfeld, the former astronaut who now heads NASA’s Science Mission Directorate, thinks that traveling light could get people to Mars by the 2040s

Jupiter's Great Red Spot is its particular crimson shade because of the interaction of ultraviolet light and specific chemical compounds in the gas giant's atmosphere. Lee Billings reports

Over the summer researchers identified seven specks of dust returned to Earth by the Stardust spacecraft. But determining their true origin has been difficult. Clara Moskowitz reports