M81

M81 and M82 are perhaps the most famous pair of galaxies in the sky and both can be seen in the same low magnification field of view. Both are spiral galaxies but M81 is nearly face on, while M82 is edge on. The contrast offered by these two galaxies is one of the visual delights of the night sky. M81 is one of the brightest galaxies in the Messier catalog and can be seen with most binoculars. Long exposure photographs display two prominent spiral arms, which may also be observed with larger telescopes. M81 and M82 are separated by only 150 000 light years. Tens of millions of years ago, the larger (and ten times as massive) M81 passed close by its smaller neighbour, inducing a round of starburst formation in M82.