From YouTube, produced by Jim Keller and Michelle Thaller
This short video is part of the series "Ask the Astronomer." The question proposed is the title isn't as simple to answer as you might think! The Andromeda Spiral Galaxy is one possible answer (it's about 2,000,000 light years away from us). However, there are also several dwarf galaxies which are much closer (as close as 25,000 light years away). Watch this short video for the details. Run time 02:34.