A gigantic cosmic cold front in the Perseus galaxy cluster spans ~2 million light years! The front has been hurtling through the cluster at roughly 300,000 mph for more than 5 billion years — that's longer than the existence of our Solar System! #News: https://t.co/FJ4X4YbiP3 pic.twitter.com/iREN07uJtm

— Chandra Observatory (@chandraxray) April 3, 2018