Junk Diet Rewires Rat Brains

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

Choosing a user name starting with a letter appearing earlier in the alphabet is just one scientifically vetted way to increase the odds of turning an online encounter into a first date. Christopher Intagliata reports

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

High-calorie and exceedingly pleasurable foods appear to change rat brain rewards circuitry, causing the rodents to continue to seek such fare. Erika Beras 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

Parkinson’s patients derived more benefits from a salt solution they were told was an expensive drug than from the same solution when it was described as being cheap medication. Karen Hopkin 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