"The surface of the Earth is the shore of the cosmic ocean... Recently, we've managed to wade a little way out, and the water seems inviting." - Carl Sagan
The Vela supernova remnant
About 11 000 years ago a star in the constellation of Vela (the sails) exploded. Today the Vela supernova remnant spans 100 light-years, appearing 20 times the diameter of the full Moon. As gas flies away from the exploded star it reacts with the interstellar medium, causing radiation emission at many different wavelengths.
Credit: Davide De Martin