Clues left at a galactic hit-and-run
Unusual gas ripples offer signs of a dwarf galaxy speeding away
GALACTOSEISMIC ACTIVITY The Milky Way’s gas (left image) and stars (right) might have been disturbed by a close run-in with a dwarf galaxy (blob at bottom left of both images), as seen in this computer simulation.
Sukanya Chakrabarti/Rochester Institute of Technology