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Astronomy

The Role of Cosmic Dust in Extragalactic Observations

Quick fact

Cosmic dust can dim a distant galaxy's light by a factor of several tens in the ultraviolet, while barely affecting the infrared—so a galaxy that looks faint and red may actually be brilliant and blue behind the dust screen.

Why this is interesting

When we look at distant galaxies, we see through a haze of tiny particles that alter what we observe. How does cosmic dust trick us into misjudging galaxy brightness and distance?