Galactic cannibalism…. Just the name must intrigue you!
If two galaxies traveling through outer space happen to pass close enough to each other they will interact. Often they will be "nice" and just push and tug on each other a little bit, distorting their shapes. But sometimes galaxies pass so close that they collide and consume one another! The system above is a real Hubble Space telescope image of the whirlpool galaxy system. The galaxy on the left, and what's left of the galaxy on the right collided a short time ago. The left galaxy was initially larger and has a larger black hole at it's center than the right one. Because of this, the left galaxy is slowly "eating" the right galaxy by stripping off all of the right galaxy's gas, dust, and stars. A true example of galactic cannibalism!
Did you know that our own galaxy, the Milky Way, expects the suffer the same fate? We are on a high speed collision course with our neighboring (and much larger) galaxy, Andromeda. When we finally collide, Andromeda is expected to cannibalize us! But don't get too worried, even though we are hurtling towards each other at 80 miles/second (yes, I mean per second!), we have about 3 billion years before the collision actually occurs. Phew!
Image Credit: NASA/HST
