IC 443: The Jellyfish Nebula

Explanation: Why is this jellyfish swimming in a sea of stars? Drifting near bright star Eta Geminorum , seen at the right, the Jellyfish Nebula extends its tentacles from the bright arcing ridge of emission left of center. In fact, the cosmic jellyfish is part of bubble-shaped supernova remnant IC 443, the expanding debris cloud from a massive star that exploded . Light from the explosion first reached planet Earth over 30,000 years ago . Like its cousin in astronomical waters, the Crab Nebula supernova remnant IC 443 is known to harbor a neutron star -- the remnant of the collapsed stellar core. The Jellyfish Nebula is about 5,000 light-years away. At that distance, the featured image would span about 140 light-years across.

Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)