Accidents in the Universe
The universe in some places can be a very violent place to live in, especially where galaxies get too close to each other… When they get too close, their strong gravity will pull them together and they will eventually collide.
Like this:
or like this:
or like this:
When galaxies collide, they trigger bursts of star formation and sometime merged to become new larger galaxies. And this will happen “soon” in our neighbourhood, to our own galaxy, in about two billion years from now.
Our Milky Way Galaxy in the past had encountered and consumed numerous smaller galaxies, growing bigger and stronger. And now it is heading towards its giant neighbour, the Andromeda galaxy, at approximately 500,000 km/hour. They will eventually collide and merged to become an elliptical galaxy, named “Milkomeda” or “AndroMilway”, you decide.
Although galaxies collide, the stars in the galaxies themselves do not collide. There are still a lot of spaces between the stars for them to actually bump into each other.
If you like the pictures above, then you must have this poster featuring all the 59 colliding galaxies that Hubble had just released (small 255 kB, large 1.36 MB). The Hubble Space Telescope has released this series of 59 colliding galaxies, the largest collection ever published simultaneously, to celebrate its 18th birthday. Hubble was launch on 24 April, 1990, and has since returning fabulous images of our universe.
If still picture is not enough for you, the HubbleSite even has videos on colliding galaxies! Go and see how violent our universe can be.
My Dark Sky 
[…] Halton Arp is an American astronomer who had catalogues quite a numbers of unusual or peculiar galaxies titled Atlas of Peculiar Galaxies, which almost all of them later turned out to be interacting and merging galaxies, which is quite common in our universe. […]
Two Galaxies Holding Hands « My Dark Sky said this on June 27, 2008 at 4:04 pm |