18 
In four billion years, Andromeda will collide with the Milky Way. That will be an amazing view—but until then we have to look at it from a distance. This new photo by the European Space Agency’s Herschel Space Observatory shows a beautiful sight. From NASA:
The glow seen here comes from the longer-wavelength, or far, end of the infrared spectrum, giving astronomers the chance to identify the very coldest dust in our galactic neighbor. These light wavelengths span from 250 to 500 microns, which are a quarter to half of a millimeter in size. Herschel’s ability to detect the light allows astronomers to see clouds of dust at temperatures of only a few tens of degrees above absolute zero. These clouds are dark and opaque at shorter wavelengths. The Herschel view also highlights spokes of dust between the concentric rings.
I just can look at these space images all day long. [NASA]
Spectacular View of Two Seemingly Colliding Galaxies Captured By Hubble
US Army's Pixellated Camo Uniform Is a £3 Billion Failure
If There Are 17 Billion Earth-Sized Worlds In Our Galaxy, the Universe Is Bubbling With Life
Well we all gotta go sometime.
I may be wrong, but during a galaxy collision, no actual stars collide. The 2 galaxies appear to crash into each other and affect each other through gravitational pull, but due to the massive amounts of empty space, the chances of 2 stars colliding is fairly small and it is by no means the end of either galaxy.
Yeah I know, I was being sarcastic.
By then, we will colonise most of the star systems