Oldest Spiral Galaxy in Universe Discovered -An artist's rendering of galaxy which is billion light-years from Earth, & its companion dwarf galaxy(upper left). (Dunlap Institute for Astronomy & Astrophysics/Joe Bergeron/Yahoo! news)
NGC 5426 and 5427 interacting. Each of these spiral galaxies contains several hundred billion stars; our own galaxy is estimated to contain anywhere from 200 billion to 400 billion. Some estimates suggest the Universe holds up to 500 billion galaxies.
The Spiral M100 is a large galaxy similar to our own Milky Way, containing over 100 billion stars. It is over 150 million light years away, so the light we see left when dinosaurs roamed the Earth. The picture was taken in 1993 with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope.
Marvel At The Sparkling, Spiraling Majesty Of The M100 Galaxy Messier 100, or M100, is a grand design spiral galaxy that contains over 100 billion stars. This Hubble Space Telescope image was made in 2009, but there's even more history here; look carefully for the "small spot that is a light echo from a bright supernova that was recorded years before the image was taken."
NGC 6240: An enormous cloud of hot gas is surrounding two merging spiral galaxies. This gas reservoir contains the mass of 10 billion Suns, spans 300,000 light years, and radiates at more 7 million degrees. A burst of star formation that lasted for at least 200 million years may be responsible for this extra large cloud of hot gas. - Credit: NASA et al