What is a SNR one may ask? A star’s gravity tries to squeeze the star into the smallest, tightest ball possible, while the nuclear fuel burning in the star’s core creates strong outward pressure, resisting the inward squeeze of gravity. But when a massive star runs out of fuel, it cools off causing the pressure to drop. Gravity wins and the star suddenly collapses creating an enormous shock wave that cause the outer part of the star to explode. The star is now said to have gone Supernova. The Vela supernova exploded approximately 11,000–12,300 years ago and what we see in the image is the leftovers of that giant explosion….the Vela SNR, or supernova remnant.