Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light.
Using data from the Herschel Space Observatory, astronomers have detected for the first time cold water vapor enveloping a dusty disk around a young star. The findings suggest that this disk, which is poised to develop into a solar system, contains great quantities of water, suggesting that water-covered planets like Earth may be common in the universe. Herschel is a European Space Agency mission with important NASA contributions.