Spiral Galaxies in Collision
From NASA’s Astronomy
Picture of the Day
Billions of years from now, only one
of these two galaxies will remain. Until then, spiral galaxies NGC
2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked
gas, lanes of dark dust, bursts of star
formation, and streams of cast-away
stars.
Astronomers predict that NGC 2207, the
larger galaxy on the left, will eventually incorporate IC 2163, the
smaller galaxy on the right.
In the most recent encounter that about peaked 40
million years ago, the smaller galaxy is swinging around counter-clockwise, and
is now slightly behind the larger galaxy. The space between stars is so vast
that when galaxies collide, the stars in them usually do not collide.
Image Credit: Debra Meloy Elmegreen (Vassar College) et al.,
& the Hubble Heritage Team (AURA/STScI/NASA)
