NGC 6782 Galactic Ring

NGC 6782

NGC 6782 is a relatively nearby galaxy, residing about 183 million light-years from Earth. The light from galaxies at much larger distances is stretched to longer, redder wavelengths ["redshifted"], due to the expansion of the universe. This means that if astronomers want to compare visible-light images of very distant galaxies with galaxies in our own neighborhood, they should use ultraviolet images of the nearby ones. Astronomers find that the distant galaxies tend to have different structures than nearby ones, even when they use the correct procedure of comparing visible light in distant galaxies with ultraviolet light from nearby ones. Since the distant galaxies are seen as they were billions of years ago, such observations are evidence that galaxies evolve with time.