Spiral Galaxies NGC 2207 and IC 2163

Two spiral galaxies are seen passing by each other like majestic ships in the night in this Hubble Space Telescope image. The larger and more massive galaxy on the left is cataloged as NGC 2207 and the smaller one on the right is IC 2163. Strong tidal forces from NGC 2207 have distorted the shape of IC 2163, flinging out stars and gas into long streamers stretching out a hundred thousand light-years toward the right-hand edge of the image. Calculations indicate that IC 2163 is swinging past NGC 2207, having made its closest approach 40 million years ago. However, IC 2163 does not have sufficient energy to escape from the gravitational pull of NGC 2207, and is destined to be pulled back and swing past the larger galaxy again in the future. Trapped in their shrinking, mutual orbit, these two galaxies will continue to distort and disrupt each other. Eventually, billions of years from now, they will merge into a single, more massive galaxy. It is believed that many present-day galaxies, including the Milky Way, were assembled from a similar process. For more information, visit: hubblesite.org/news_release/news/1999-41 For a multiwavelength view of these galaxies, see: hubblesite.org/video/1021