... Wisps of dust fill the space between the stars. ... Sometimes this dust is thick and prominent as dark patches on otherwise bright emission nebulae. Other times this dust may show itself by reflecting the light of bright, nearby stars. ... Dark spots that might appear on the image are usually sunspots, dark magnetic depressions that are slightly cooler than the rest of the Sun's surface. ... Hyakutake: Comet Atmosphere . ... The atmosphere of a comet comes and goes. ... Return To Cydonia . ...