3.5 million km/h Galaxy Collision

Galaxy Abell 2667. NASA, ESA, and J. -P. Kneib (Laboratorie d’Astrophysique de Marseille)

A Macrch 2007 press release from the HubbleSite details new Hubble observations, made by an international team of astronomers led by Luca Cortese of Cardiff University, United Kingdom:

While looking at galaxy cluster Abell 2667, astronomers found an odd- looking spiral galaxy (shown in the upper left hand corner of the image) that plows through the cluster after being accelerated to at least 3.5 million km/h by the enormous combined gravity of the cluster’s dark matter, hot gas and hundreds of galaxies. As it speeds through, it rams into the hot gas that permeates the cluster. Its gas and stars are pulled away by the gravitational tidal forces exerted by the cluster, just as the forces exerted by our moon and sun pull the Earth’s oceans..[HubbleSite]

[From HubbleSite]