A skyscraper-size asteroid flew closer to Earth than the moon — and scientists didn’t notice until 2 days later

A stealthy asteroid the size of a 20-story building hid in the sun’s glare before zooming uncomfortably close to Earth on July 13. Scientists didn’t notice until July 15. An … Read More

Gargantuan Black Hole ‘Switches On,’ Becoming One Of The Brightest Objects Ever Seen.

A black hole 10 billion light-years away suddenly ‘switched on’, becoming one of the brightest transient objects ever detected. Scientists scouring the cosmos for signs of a rare explosion may … Read More