The Universe may be brighter than thought: perhaps twice as bright as seen from Earth.
Interstellar cosmic dust absorbs some starlight, but quantifying this has proved difficult. Researchers from the United Kingdom, Germany and Australia looked closely at how dust obscures light in some nearby galaxies, depending on various factors including the size, shape and inclination of the galaxy. They used these data to make a better model of how dust absorbs light, and applied the model to a catalogue of 10,000 galaxies.
The result suggests that dust is blocking nearly half of this light from our view, making the true brightness of the nearby Universe nearly twice that seen from Earth (S. P. Driver et al. Astrophys. J. Lett. 678, L101–L104; 2008). The researchers say that their findings could force a revision in mass estimates for dust-shrouded galaxies, and a reconsideration of models of galaxy formation in the early Universe.