Interstellar Dust

During this past week, I have been pretty busy getting ready for a competition with my robotics team at Sacramento, so I didn't have as much time to read and further my project.

However, I did some light reading on interstellar dust, which are tiny particles that absorb or scatter light from stars. When absorption and scattering of light is combined, it is called extinction. The term "reddening" comes from the fact that the effect is much stronger in blue light than red light.

Effects of interstellar dust can lead to very pretty pictures because large clouds of dust can actually reflect the light of nearby stars which creates reflecting nebulae (like the Witch Head nebulae associated with Rigel part of the Orion constellation).

The difference between absorption and scattering of the photon or light is how the energy from the light is used. In absorption, the dust particle takes in the energy and is heated, while in scattering, the photon "bounces off" and is redirected to another direction. In the diagram, the red line shows the effect of absorption, while the blue line shows the effect of scattering.