When the star Cassiopeia A exploded, nearly all the iron from the core was expelled to the outer regions of the supernova. John Matson reports

Supernova Turned Star Inside-Out

Leading science journalists provide a daily minute commentary on some of the most interesting developments in the world of astronomy and space exploration

Science

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

Bacteria Got an Early Fix on Nitrogen

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

Stars Reveal Hidden Galaxy

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

Space Science Budget Gets Small Lift

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

5 Rocky Planets Found in Ancient, Distant Solar System

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

Supernova Turned Star Inside-Out

Download our free app to listen on your phone