Simeis 147: Supernova Remnant . ... Credit Copyright: Nobuhiko Miki Explanation: It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147. ... That corresponds to a width of 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. ... This supernova remnant has an estimated age of about 40,000 years - meaning light from the massive stellar explosion first reached Earth 40,000 years ago. ...