This was
your sky.

Supernova Remnant Cassiopeia A

Cassiopeia A is an expanding debris cloud from a massive star's supernova explosion. This remnant is a prime example of the final phase of a star's life, where enriched material is blasted back into space. Light from the supernova reached Earth around 1680, though it was not widely observed at the time. It is about 11,000 light-years away in the constellation Cassiopeia.