Why Is Andromeda Coming Towards Us?

Rendering of how the collision might look from an Earth-like planet (Credit: NASA, ESA, Z. Levay, R. Van Der Marel (STSci), T. Hallas, A Mellinger)
Rendering of how the collision might look from an Earth-like planet (Credit: NASA, ESA, Z. Levay, R. Van Der Marel (STSci), T. Hallas, A Mellinger)

As you may have heard, here in about 5 billion years, the Milky Way won’t exist as a singular entity anymore. Rather, as we speak, the Andromeda Galaxy — the Milky Way’s largest neighbor, which currently lurks more than 1,500,000 light-years away from Earth — is slowly inching its way toward us, and the two will eventually become one

Once that day arrives, Earth will probably be a smoldering pile of ash — having been gobbled up by the Sun a billion years (or so) before — but if humanity manages to survive by relocating elsewhere, the view will be rather fantastic.

On the surface, Andromeda’s current flight path toward our home galaxy poses a bit of a conundrum: if the universe is expanding as astronomers say, surely Andromeda, like everything else (the Moon included) would be moving away from us. Why is the opposite true?

WATCH: “Why Is Andromeda Coming Towards Us?”

Why Is Andromeda Coming Towards Us? If Everything is Expanding Away From Each Other thumbnail
Why Is Andromeda Coming Towards Us? If Everything is Expanding Away From Each Other
Jaime is a freelance writer, who finds great joy in sharing the wonders of universe with others. She used this passion to launch "From Quarks to Quasars" in 2012.