This artist's illustration shows spiral galaxy ESO 137-001 in 3D. The galaxy is undergoing a process known as ram pressure stripping, where streaks of bright gas are being dragged out into space by the cluster it is moving through.
More information and download options: http://www.spacetelescope.org/videos/heic1404d/
Credit: NASA, ESA, and M. Kornmesser
Acknowledgements: Ming Sun (UAH) and Serge Meunier