The image on the right was taken in 1999 with the Chandra X-ray Observatory's 0.3-10.0 keV Advanced Imaging Spectrometer, and covers an area of 7.5 x 7.2 arc minutes. It shows a colossal cosmic "weather system" produced by the collision of two giant clusters of galaxies. For the first time, the pressure fronts in the system have been traced in detai. They show a bright, but relatively cool 50 million degree Celsius central region (white) embedded in large elongated cloud of 70 million degree Celsius gas (magenta), all of which is boiling in a faint "atmosphere" of 100 million degree Celsius gas (faint magenta and dark blue). The bright source in the upper left is an active galaxy in the cluster.