Monday, June 30, 2008

When Galaxies Collide!

A pair of galaxies imaged by the Gemini Observatory in Hawaii are on a collision course, a powerful gravitational phenomenon when two galaxies pull each other closer so that they eventually either merge or pass through one and other, creating severe and, to us, beautiful disruptions, mostly by exciting star formation.

The image is fascinating, almost unrealistic in its clarity and beauty. Both are spiral galaxies and both are showing all or most of their face to us; a marvelous image that inspires the imagination to the great wonders of the universe. Not only is the size scale immense, but the timeframe over which this process (collision) is talking place is millions of years; a ballet of cosmic leviathans.

This is similar to what the Milky Way (our home galaxy) and Andromeda will look like when they eventually collide, a forgone conclusion according to scientists.

The Gemini Observatory website says this:

Once thought to be unusual and rare, gravitational interactions between galaxies are now known to be quite common (especially in densely populated galaxy clusters) and are considered to play an important role in galaxy evolution. Most galaxies have probably had at least one major, if not many minor, interactions with other galaxies since the advent of the Big Bang some 13 billion years ago. Our own Milky Way, a spiral galaxy like those in this image, is, in fact, performing its own stately dance. Both with the nearby dwarf galaxy, called the Large Magellanic Cloud and a future interaction with the large spiral galaxy M-31 or the Great Andromeda Galaxy, which is now located about 2.6 million light years away from the Milky Way. This new Gemini image is possibly a preview of things to come for our own galaxy. Ultimately the end result of these types of collisions will be a large elliptical galaxy.

Read all about it either at the Astronomy Magazine website or in the Gemini Observatory press release.

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