Milky Way flipped in collision with dwarf galaxy 10bn years ago, astronomers say

Durham University researchers find cataclysmic direct hit with Gaia Sausage sent Milky Way into its current position

Published 21 July 2026 110 words
SCIENCE A1
Milky Way flipped in collision with dwarf galaxy 10bn years ago, astronomers say

Our galaxy, the Milky Way, was flipped over a long time ago. This happened when it crashed into another small galaxy.

The big crash was about 10 billion years ago. A small galaxy called the Gaia Sausage hit the Milky Way. The Milky Way broke the Gaia Sausage apart and took its stars. This big event probably turned the Milky Way over.

Scientists at Durham University used computers to study this. They saw that when galaxies like ours hit a galaxy like the Gaia Sausage, the galaxy's flat part can flip. It takes a very long time, maybe more than 100 million years.

The scientists looked at how stars move. They saw that stars in the outer part of the Milky Way move much slower than stars closer to the centre. This helped them understand the big crash.

Vocabulary

galaxy — A very large group of stars, gas, and dust in space.
collision — When two things crash into each other.
dwarf galaxy — A small galaxy.
researchers — People who study something to learn new things.
simulations — Computer programs that show how something might happen.

Discussion Questions

  1. What is the name of the small galaxy that hit the Milky Way?
  2. How long ago did this big collision happen?
  3. What did the scientists use to study the galaxy collision?

Based on an article from The Guardian.

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