Artwork of the system M51 formed by the spiral galaxy NGC 5194 and its companion, the irregular galaxy NGC 5195, based on the high resolution imagery of the Hubble Space Telescope (HST). HST was designed to improve the resolution of ground based astronomical observations, limited by atmospheric turbulences. It improved the resolution by a factor of ten and it expanded the volume of the observable universe 350 times. M51 lies some 13 million light years from the Earth in the constellation of Canes Venatici. The inner parts of NGC 5194 are populated by old yellow stars whereas much bluer and younger stars are present in the spiral arms.