These images of the galaxy cluster Abell 1775 show X-rays from Chandra, optical data from the Pan-STARRS telescope in Hawaii, and radio data from the LOw Frequency ARray (LOFAR) in the Netherlands. A tail from the merged cluster is seen, along with a region of gas with a curved edge, called a "cold front", that is denser and cooler than the gas it is plowing into (see labeled version). The tail and the cold front all curve in the same direction, creating a spiral appearance. These features are the result of two galaxy clusters — the largest structures held together by gravity — crashing into one another, one of the most energetic events in the Universe..