Neutron stars are some of the weirdest cosmic objects, and the greatest mysteries lie deep in their hearts.

Is your green my green? Probably not. What appears as pure green to me will likely look a bit yellowish or blueish to you.

A distant flicker of light from a star can reveal more than you might expect. In fact, a brief, subtle brightening in the sky ...

The school-bus-sized observatory launched on April 24, 1990 and overcame early setbacks to become one of the most ...