Comet C/2017 T2 (PANSTARRS) visits M81/M82

On May 21, 2020, comet C/2017 T2 (PANSTARRS), from our vantage point, passed alongside the galaxies M81, M82, and NGC 3077. While waiting for another target to rise, I trained my equipment on this area of the sky for a brief 36 minutes of data.

Despite the apparent proximity, in reality these objects provide an exercise in contemplating distances in the universe, as the comet is a denizen of our own solar system. On this night, the comet was approximately 249 million kilometers from earth (about 1.7 astronomical units), so it took the light from the comet approximately 14 minutes to reach my camera. M81 and M82 are 200,000,000,000,000,000,000 kilometers away, so the light from those galaxies took 12 million years.

For a more detailed image of M81 and M82, click here .