| Unlike most of the nebulas that populate the universe, these clouds are limned by arcs or tings and bathed in the blue light emitted by helium ions. |
| We have missions that include active nebulas, swirling dust clouds, moving asteroids and asteroid fields. |
| For nebulas there are emission nebula, reflection nebulas, planetary nebulas, dark nebulas and supernova remnants. |
| There are different forms of nebulas, dark nebulas, emission nebulas and celestial nebulas. |
| Astronomers suspect that the distant emissions may emanate from the same type of nebulas. |
| Both dark nebulas and luminous nebulas are considered likely sites for the processes of dust-cloud condensation and the formation of new stars. |
