Interstellar dust clouds make the dark skies blue

Interstellar dust clouds make the dark skies blue

[CLICK ON IMAGE FOR HIGH RESOLUTION.] This lovely blue cosmic cloud begins the van den Bergh Catalog (vdB) of stars surrounded by reflection nebulae. Interstellar dust clouds reflecting the light of the nearby stars, the nebulae usually appear blue because scattering by the dust grains is more effective at shorter (bluer) wavelengths. The same type […]