M81 and M82 are perhaps the most famous pair of galaxies in the sky. Both can be seen in the same low magnification field of view and both are spiral galaxies. However, M81 is viewed nearly face-on, while M82 is edge-on.

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.

This could have been the scene of a colossal cosmic collision. It's astounding to realize that what you're actually seeing is the result of a very near miss. Tens of millions of years ago, the larger (and ten times as massive) M81 passed close by its smaller neighbor. As a result of the rising star tides during that encounter, M82 now glows with the fireworks of starburst formation.

Click here to see if this object is visible in your sky tonight.