One of the gems of the night sky, the galaxy M51 is easily found with a small telescope in Canes Venatici. Known as the Whirlpool for obvious reasons, we are actually seeing two galaxies - M51 and its smaller companion NGC5195. M51 was the first galaxy to be observed to have spiral structure, by Lord Rosse using the 72 inch diameter Parsonstown telescope in 1845 - the first link in the chain ending in proof that galaxies exist beyond our own. For a long time it was thought that the two galaxies were interacting, but although they are both about 15 million light years away high resolution photography has proved quite conclusively that M51's outermost arm passes in front of NGC5195. The images were taken with different sizes of telescope.