Behold: M101, aka The Pinwheel Galaxy – 25 million light years away within the boundaries of the Ursa Minor constellation. One of the last entries in Charles Messier’s catalogue of astronomical objects but by no means the least. To wit:
About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy. M101 was also one of the original spiral nebulae observed with Lord Rosse’s large 19th century telescope, the Leviathan of Parsonstown (Birr, county Offaly). In contrast, this multiwavelength view of the large island universe is a composite of images recorded by space-based telescopes in the 21st century. Colour coded from X-rays to infrared wavelengths (high to low energies), the image data was taken from the Chandra X-ray Observatory (purple), the Galaxy Evolution Explorer (blue), Hubble Space Telescope (yellow), and the Spitzer Space Telescope(red). While the X-ray data trace the location of multimillion degree gas around M101’s exploded stars and neutron star and black hole binary star systems, the lower energy data follow the stars and dust that define M101’s grand spiral arms.