The outer edges of the Milky Way's appear to be orbited by innumerable invisible galaxies, one of which appears to be crashing into our own. In 2005 astronomers discovered the first evidence of mysterious dark galaxies with no starlight -.
Carina Nebula Dust Pillar looks like a small speck of dust in our infinite universe, but it is actually almost 2 light-years wide. For reference, 1 light-year is almost 6 trillion miles! Source: NASA, ESA, and the Hubble ERO Team