A new study reveals an odd peculiarity of a massive shock wave traveling through a cloud of gas left behind by the stormy death of a star. Research suggests that part of it is traveling in the wrong direction.

Cassiopeia A is a gas cloud, or nebula, left behind by a supernova in the constellation Cassiopeia. The constellation lies approximately

Source: Hot Hardware – A Spectacular Galactic Explosion Has Sent Reverse Shock Waves That Defy Supernova Models