The robots that will sweep Earth’s skies

After six years in space, China's first orbital station, the Tiangong-1 (aka the "Heavenly Palace") has finally outlived its operational limits and begun its descent back to Earth. It's expected to re-enter the atmosphere in a few months, whereupon a...

Astronomers just measured a whole lot more than gravitational waves

A couple of weeks ago, the LIGO (Laser Interferometer Gravitational-Wave Observatory) and Virgo teams announced the detection of another set of gravitational waves -- the fourth since LIGO's first detection in September of 2015. The observations of t...