M82 is an extremely active 'starburst galaxy', where new stars are being formed at a furious pace. Due to a past interaction with M81, the galaxy is heavily disturbed, which has led to powerful gas currents being blown perpendicularly out of the center. These outflowing filaments are spectacularly visible in H-alpha and give M82 its characteristic reddish appearance in astrophotographs. The core is chaotic, bright, and rich in star-forming regions. M82 is one of the most photogenic and dynamic galaxies in the northern sky.