The spiral galaxy ESO 137-001 looks like a dandelion caught in a breeze in this stunning space wallpaper from Hubble Space Telescope. The galaxy is zooming toward the upper right of this image, in between other galaxies in the Norma cluster located over 200 million light-years away. The road is harsh: intergalactic gas in the Norma cluster is sparse, but so hot at 180 million degrees Fahrenheit that it glows in X-rays. The spiral plows through the seething intra-cluster gas so rapidly — at nearly 4.5 million miles per hour — much of its own gas is caught and torn away. Astronomers call this "ram pressure stripping." The galaxy's stars remain intact due to the binding force of their gravity.
(Image: © NASA, ESA, and the Hubble Heritage Team (STScI/AURA); Acknowledgment: M. Sun (University of Alabama, Huntsville))