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Why do galaxies have similar appearances when we see them in many of the NASA images?
Pictures of far away galaxies like the latest images taken 25 million light years away by NASA’s Hubble Telescope show that galaxies like our own Milky Way are shaped like pancakes: flat and wide.
There are four different galaxy shapes in the universe that are known to science including spiral, elliptical, lenticular, and irregular.
The reason behind these galactic shapes is that each of the known galaxies started as a ball of gas, slowly rotating in space.
Gravitational forces caused by the rotating gas collapsing on itself pulled other matter into its orbit, creating the flat circular pancake shaped galaxies that we see in satellite images from space.
By taking this shape, angular momentum is conserved and the galaxy becomes the most physically adept shape for cosmic motion, similar to pizza dough being spun and tossed into the air to make a disc shape.
One way of testing this physics lesson is by spinning around in your office chair.
If you pull your arms and legs closer to your body, the chair should spin faster because there is less resistance to the force of the turn.
Try it and tell us what you think about the shape of galaxies in the universe.