Cosmic Collisions - Galaxies Gone Wild

Fifty-nine images of colliding galaxies make up the largest collection of Hubble images ever released together. As this astonishing Hubble atlas of interacting galaxies illustrates, galaxy collisions produce a remarkable variety of intricate structures.

Interacting galaxies are found throughout the Universe, sometimes as dramatic collisions that trigger bursts of star formation, on other occasions as stealthy mergers that result in new galaxies. A series of 59 new images of colliding galaxies has been released from the several terabytes of archived raw images from the NASA/ESA Hubble Space Telescope to mark the 18th anniversary of the telescope's launch. This is the largest collection of Hubble images ever released to the public simultaneously.

Galaxy mergers, which were more common in the early Universe than they are today, are thought to be one of the main driving forces for cosmic evolution, turning on quasars, sparking frenetic star births and explosive stellar deaths. Even apparently isolated galaxies will show signs in their internal structure that they have experienced one or more mergers in their past. Each of the various merging galaxies in this series of images is a snapshot of a different instant in the long interaction process.

Our own Milky Way contains the debris of the many smaller galaxies it has encountered and devoured in the past, and it is currently absorbing the Sagittarius dwarf elliptical galaxy. In turn, it looks as if our Milky Way will be subsumed into its giant neighbour, the Andromeda galaxy, resulting in an elliptical galaxy, dubbed "Milkomeda", the new home for the Earth, the Sun and the rest of the Solar System in about two billion years time. The two galaxies are currently rushing towards each other at approximately 500,000 kilometres per hour.

• http://www.spacetelescope.org/news/ht...

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Hubblecast features news and Images from the Hubble Space Telescope (HST).

The space-based observatory is a collaboration between NASA and ESA. The observations are carried out in visible, infrared and ultraviolet light. In many ways Hubble has revolutionised modern astronomy.

The Hubble Space Telescope has made some of the most dramatic discoveries in the history of astronomy. From its vantage point 600 km above the Earth, Hubble can detect light with "eyes" five times sharper than the best ground-based telescopes and looks deep into space where some of the most profound mysteries are still buried in the mists of time.

• http://www.eso.org
• http://www.spacetelescope.org
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Dr. J is a German astronomer at the ESO. His scientific interests are in cosmology, particularly on galaxy evolution and quasars. Dr. J's real name is Joe Liske and he has a PhD in astronomy.

• http://www.eso.org/~jliske/