Mysterious ‘Diamond Ring’ in space isn’t what it seems

Today's Image of the Day from NASA's Jet Propulsion Laboratory shows a striking feature in the star-forming region Cygnus X that astronomers call the “Diamond Ring.”  At first glance, it looks like a shimmering loop of light set against a busy background of stars. The Diamond Ring has been a familiar sight to infrared telescopes for years, but its unusual shape has puzzled researchers for just as long.  How the Diamond Ring is different  Many rings in space form as perfect spheres, yet...