Atom & Cosmos

Huge halo may hold missing matter
The Milky Way galaxy is cocooned inside an enormous cloud of hot gas, a finding that could solve a persistent astrophysical conundrum. Heated to more than 1 million degrees Celsius, the halo extends more than 300,000 light-years from the galactic center and contains at least as much mass as 10 billion suns, scientists report in the Sept.