A strange, starless cloud on the edge of a nearby galaxy is forcing astronomers to confront one of the biggest unknowns in physics. The object, nicknamed Cloud‑9, looks like a wisp of hydrogen gas, ...

Add Yahoo as a preferred source to see more of our stories on Google. An artist's impression of the accretion disk around the compact object in the X-ray binary system Cygnus X-3, showing the X-rays ...

We preselected all newsletters you had before unsubscribing.