A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the ...

For years, astronomers have been puzzled by the presence of two gigantic, high-energy “bubbles” towering over and beneath the Milky Way’s center, extending 50,000 light-years into space. First ...

Conflicting distance measurements have added to the uncertainty. One data source places one object at 6,500 light years away, ...

The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty Images ...

In the heart of our Milky Way galaxy, two gigantic "bubbles" extend roughly 50,000 light-years above and below the galactic ...