LMR-066 · Galaxies
Andromeda
Our nearest big neighbor. Will collide with us in 4.5 billion years.
§ A first look
§ Depths
Six ways into the same idea — from bedtime story to chalkboard. No order required.
L1 · Crayon
Told like a bedtime story.
For a curious 10-year-old. No jargon. Just a picture in your head.
On a very dark night, far from city lights, you can sometimes spot a faint fuzzy little smudge in the sky. With your bare eyes it looks like nothing much — like the lens of your eye got smudged. But that smudge is actually another entire galaxy — about a trillion stars together — called Andromeda. It's the closest big galaxy to our own Milky Way. Its light has been flying through space for about two and a half million years to reach your eyeball tonight. It's also slowly drifting toward us, and in about four and a half billion years it will crash into our galaxy and merge with it. Save the date.
§ Strange but true
- 01It's the only galaxy you can see with the naked eye from a dark sky — a faint smudge that is 2.5 million light-years away.
- 02The light hitting your eye left Andromeda before Homo sapiens existed.
- 03It's heading toward us at 110 km/s. Merger inbound — but the night sky will mostly look the same. Galaxies are mostly empty.
§ From the field journal
Andromeda
"Our nearest big neighbor. Will collide with us in 4.5 billion years."
— observed, sketched, not yet fully understood.
§ Nearby
Constellations near Andromeda
→
Galaxy
A herd of a hundred billion stars, held together by gravity and dark matter.
→
Cosmic Web
Galaxies don't drift randomly. They live on filaments around vast empty voids.
→
Dark Matter
Most of the universe is invisible. We only see its footprints.
→
Black Hole
A place in the sky where the door only opens one way.