Missing baryons found in far-out reaches of galactic halos

Researchers have channeled the universe's earliest light--a relic of the universe's formation known as the cosmic microwave background (CMB)--to solve a missing-matter mystery and learn new things about galaxy formation. Their work could also help us to better understand dark energy and test Einstein's theory of general relativity by providing new details about the rate at which galaxies are moving toward us or away from us.