Milky Way and the Dwarf Galaxies Collision

Our galaxy, the Milky Way, is surrounded by many other small galaxies. Some of these include dwarf galaxies which are very small as compared to the Milky Way. In the past, these dwarf galaxies have been colliding with the Milky Way but because of its huge size Milky Way showed no significant change in its shape or behavior, so in short our galaxy is not likely to be destroyed by these small galaxies. The previous thoughts of colliding galaxies involved rip and tear motion but this actually happens if a big galaxy like the Andromeda collides with the Milky Way, only then havoc will be created. In fact, scientists think many satellite galaxies have already rammed into the Milky Way, though so far it has endured.

Astronomers have known since 1994 that a small galaxy orbiting the Milky Way has actually entered Earth’s home galaxy. They realized that certain stars, which all had essentially the same velocity, were not moving in the proper manner to be in the center of the Milky Way.

Image shows that dwarf galaxy already entered the Milky Way. Credit: NASA/JPL

Milky Way presently is encircled by 20 to 25 dwarf galaxies which are smaller clumps of stars bound in orbit around the Milky Way by gravitational attraction. According to computer simulation collision with a dwarf galaxy produces a pancake-shaped galactic disk. Evidence of this galactic disk has been found in the form of rings and flares of stars around the edges of other galaxies’ disks. During the collision of such small galaxies the mingling which is created does not affect the stars because in the galaxies stars are so widely apart that even if mingling does occur they adjust themselves accordingly without colliding between one another. The merging of two galaxies produces firestorm of new star formation, adding to the richness of the two melded galaxies.

The bright central region corresponds roughly to the Milky Way's luminous matter of gas and stars, and the bright clumps outside indicate dark-matter satellites orbiting the Milky Way. Credit: Stelios Kazantzidis, Ohio State University

Though our galaxy might not be in danger from the dwarf galaxies, scientists do expect it to eventually collide with the nearest full-size mega galaxy, Andromeda. In a few billion years, the two spirals should smash into each other head-on, creating full devastation. Eventually both galaxies will merge together and our galaxy will be wiped off.

A simulation of what might happen when the Andromeda Galaxy hits ours shows tidal forces of gravity creating long plumes of material. The central regions will relatively quickly fall back together and merge into a single remnant galaxy.

Related posts:

1. Next Up On Andromeda’s Menu: Earth!
2. Infrared Image of Galactic Center
3. Andromeda: X-Ray View
4. Panorama View Of Our Night Sky
5. Viewing Andromeda Galaxy