Collision course
Ryan Hughes
Issue date: 11/9/09 Section: News
Experts have concluded that the Milky Way galaxy in which our solar system resides is on a collision course with the neighboring Andromeda galaxy, and although the countdown involves several billion years, the end result will be a new and separate entity of its own.
The gap between the two galaxies is closing at an estimated 600 kilometers per second (approximately 400 miles per second) and will finally close when the two galaxies come into contact with one another.
Though the galaxies will collide, the event does not imply explosive consequences. According to Dr. Michael Wood-Vasey, assistant professor of Physics and Astronomy at the University of Pittsburgh, the galaxies will combine rather peacefully.
"As the galaxies pass and interact with each other, clouds of gas and dust from both galaxies will compress and form new stars," Wood-Vasey told the Voice. "But the stars in the galaxies won't merge or collide since the gap between them is so large."
The galaxies will most likely not hit head-on. When the collision takes place, the edges of the two will not exactly hit but will get close enough for their individual gravities to affect each other.
The interfering gravities of star systems will pull on other systems, twisting the galaxies and throwing stars this way and that, causing a chain reaction all across both galaxies.
"It's not going to be stars crashing into stars," Eric Fischer, honorary member of the Amateur Astronomers Association of Pittsburgh, told the Voice. "Maybe a few will collide, but for the most part, they won't. Space is so big."
After around 10 billion years, the gravities all over the galaxies will settle at one point in which the Milky Way and Andromeda galaxies have combined, forming a new mass of stars in the universe.
"It's misleading when you hear 'crash' or 'collision,'" said Fischer. "'Merge' is more like it."
As the Milky Way and Andromeda move closer to each other, future inhabitants of Earth will look up into the night sky and see the entire elliptical Andromeda galaxy spanning a large portion of the sky.
"It would be a wonderful thing to see," said Wood-Vasey.
When the collision begins, many of the stars and constellations now visible in the night sky will disappear as stars are displaced to new locations in the new galaxy. A few stars may even break out of the new galaxy's gravity during the collision and drift out into space.
"The worst case scenario is our Sun might adopt another orbit," said Wood-Vasey.
The two galaxies will collide because they are both in the same local group comprised of about 20 galaxies all gravitationally bound together. In addition, the Milky Way and Andromeda galaxies are definitely bound toward the same place.
"The fundamental principal that the galaxies are moving toward one another remains pretty robust," said Wood-Vasey.
The gap between the two galaxies is closing at an estimated 600 kilometers per second (approximately 400 miles per second) and will finally close when the two galaxies come into contact with one another.
Though the galaxies will collide, the event does not imply explosive consequences. According to Dr. Michael Wood-Vasey, assistant professor of Physics and Astronomy at the University of Pittsburgh, the galaxies will combine rather peacefully.
"As the galaxies pass and interact with each other, clouds of gas and dust from both galaxies will compress and form new stars," Wood-Vasey told the Voice. "But the stars in the galaxies won't merge or collide since the gap between them is so large."
The galaxies will most likely not hit head-on. When the collision takes place, the edges of the two will not exactly hit but will get close enough for their individual gravities to affect each other.
The interfering gravities of star systems will pull on other systems, twisting the galaxies and throwing stars this way and that, causing a chain reaction all across both galaxies.
"It's not going to be stars crashing into stars," Eric Fischer, honorary member of the Amateur Astronomers Association of Pittsburgh, told the Voice. "Maybe a few will collide, but for the most part, they won't. Space is so big."
After around 10 billion years, the gravities all over the galaxies will settle at one point in which the Milky Way and Andromeda galaxies have combined, forming a new mass of stars in the universe.
"It's misleading when you hear 'crash' or 'collision,'" said Fischer. "'Merge' is more like it."
As the Milky Way and Andromeda move closer to each other, future inhabitants of Earth will look up into the night sky and see the entire elliptical Andromeda galaxy spanning a large portion of the sky.
"It would be a wonderful thing to see," said Wood-Vasey.
When the collision begins, many of the stars and constellations now visible in the night sky will disappear as stars are displaced to new locations in the new galaxy. A few stars may even break out of the new galaxy's gravity during the collision and drift out into space.
"The worst case scenario is our Sun might adopt another orbit," said Wood-Vasey.
The two galaxies will collide because they are both in the same local group comprised of about 20 galaxies all gravitationally bound together. In addition, the Milky Way and Andromeda galaxies are definitely bound toward the same place.
"The fundamental principal that the galaxies are moving toward one another remains pretty robust," said Wood-Vasey.