ScienceShot: Cosmic Collision Is Just a Trick of the Eye

Is this what our Milky Way and the Andromeda galaxy will look like 4 billion years from now, when they slam into each other? Not quite. It may seem as if these two spiral galaxies are colliding—the eventual fate of our galaxy and Andromeda—but they're really separated by over 20 million light-years. This trick of perspective—one is closer to us than the other, but we see them in the same direction—caught by the Hubble Space Telescope and released today by the Space Telescope Science Institute in Baltimore, Maryland, is not just another nice cosmic image. It also provides astronomers with an opportunity to study the star-spawning dark dust lanes in the smaller foreground galaxy (NGC 3314A), because they are clearly silhouetted against the bright stellar background of the second galaxy (NGC 3314B). The slight asymmetry of NGC 3314A may be due to a past encounter with another, smaller galaxy outside the picture. Look closely, and you will also see dozens of tiny, faint background galaxies in the image, located at distances of billions of light-years from Earth.

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*This item has been corrected. The two galaxies in the Hubble photograph were erroneously referred to as NGC 1334A and NGC 1334B. Their real catalogue numbers are NGC 3314A and NGC 3314B.