Most of the NASA images are the result of inputs received ... the atmosphere of planets orbiting stars. The Cassiopeia A supernova remnant captured in this image looks like a giant blue donut.

A large cluster galaxy (center of the box) has split the light from an exploding supernova in a magnified background galaxy into four yellow images (arrows) to form an Einstein Cross. This ...

A supernova is a cataclysmic stellar death that ... Credit: Alan Dyer / VWPics / Universal Images Group via Getty Images Using models that estimate how stars evolve and emit light at different ...