Dark galaxy crashing into the Milky Way
Radio telescopes detect a large cloud of hydrogen gas (contour lines) where no stars can be found (Image: R Minchin/Arecibo Observatory/Cardiff U/Isaac Newton Telescope/WSRT) Neutral hydrogen gas streams between NGC 4254 (top left) and the dark galaxy VIRGOH121 (centre right) in this radio image. The new study suggests VIRGOHI21’s gravity is responsible for NGC …