Galaxies are the gems of the universe. They form in clumps that dot the seemingly empty vacuum of space. Within these clusters, galactic collisions are common. The average galaxy, including ours, has collided or merged with another galaxy at least once it its lifetime.
Milky Way: Gobbling Up Its Neighbors for Millennia
The Milky Way has a rich past, present, and future of galactic merging. According to Amelie Saintonge of Cornell University's Ask an Astronomer, we are currently in the process of merging with a small dwarf galaxy and will eventually merge with at least eight more nearby dwarf galaxies. Though it’s a hefty two billion years away, the future event that really has astronomers buzzing is the expected merging of the Milky Way and the majestic spiral Andomeda Galaxy, which will merge to form an entirely new shape.
Milky Way + Andromeda = Milk-meda Galaxy?
What will happen to us when this cataclysmic event occurs? According to science writer Ken Thar's analysis of theorists T.J. Cox and Avi Loeb's 2007 paper The Collision Between the Milky Way and Andromeda, (Harvard-Smithsonian Center for Astrophysics) the Sun and its planets will be sent to the outer halo of the newly merged galaxy. The two galaxies will fall into eachother’s orbit for a bit, swapping dust and stars as massive gravitational forces begin destabilize their structures.
In an interview to ScienceDaily in May 2007 (When Galaxies Collide, the Solar Will Go For a Ride), Cox and Loeb explain to Thar that about 5 billion years from now Andromeda and the Milky Way will completely combine to form a single, football-shaped elliptical galaxy. Their calculations show it and the solar system will probably be sent about four times further from the center of the galaxy than we are now.
Hubbles Reveals Mergers Here, There, Everywhere
The Milky Way isn’t the only galaxy to get all the excitement. Recently, NASA released 59 tantalizing Hubble images of galaxies in mid-merge. According to Roger Lynds and Earl O’Neil Jr of the Hubble Heritage Project, in a100 million years or so, future astronomers will classify galaxy NGC 6745 as a triple system-- three galaxies in a nearly straight line! This group of galaxies is located in the constellation Lyra, about 206 million light-years from Earth.
Merging galaxies display the Universe’s dynamic side. Fantastic images and an interesting evolution make galaxy mergers exciting action scenes in a grand Universe play.
