Understand Your Galaxy
New research reveals a bigger, faster, more massive Milky Way
The Milky Way galaxy contains the sun, Earth, and a collection of more than 200 billion stars. A new study released on Monday estimates that all of those heavenly bodies together equal the weight of 3 trillion suns. (The sun is 332,950 times the Earth's weight.)
According to the study, the Milky Way is also much wider and is spinning faster than astronomers once thought.
Mark Reid, of the Harvard-Smithsonian Center for Astrophysics, is the author of the study that produced a lot of new information about the Milky Way. Reid presented his findings at the American Astronomical Society's convention in Long Beach, California. Part of his presentation included a new, more-detailed three-dimensional map of the Milky Way.
For many years, scientists believed our galaxy wasn’t the biggest one in the cosmic neighborhood. That honor went to our closest galactic neighbor, Andromeda.
Based on Reid’s findings, however, astronomers now believe the Milky Way is roughly the same size as Andromeda.
|The Andromeda spiral galaxy as seen through an optical telescope. (Photo: NASA)|
"Previously we thought Andromeda was dominant, and that we were the little sister of Andromeda," Reid told fellow astronomers at his presentation. "But now it's more like we're fraternal twins."
To remap the Milky Way, Reid and his team used a system of 10 radio-telescope antennas that stretch from Hawaii to the New England region of the U.S. and to the Caribbean. This system is called the Very Long Baseline Array, or VLBA.
The VLBA can produce images hundreds of times more detailed than the Hubble Space Telescope. These highly detailed images allowed Reid and his team to make much more precise calculations about the size of the Milky Way.
These new size and speed calculations give us a view into the future of our galaxy.
The gravitational forces (strong pulls) of the Milky Way and Andromeda are pulling the galaxies toward one another. If Andromeda and the Milky Way collide, the two could explosively merge into one new galaxy.
But a galaxy collision isn’t something to worry about right now. Reid believes a meeting between the Milky Way and Andromeda is about 2 billion to 3 billion years away.
The Hubble Telescope has captured images of galaxies that are currently in the act of merging. See some of these far away galaxies spin, slide, and collide in this slide show!
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