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Astronomy

Galactic Rotation Curves: Evidence for Dark Matter

Quick fact

The first clear evidence for dark matter from rotation curves was presented by Vera Rubin and Kent Ford in the 1970s, using the Andromeda Galaxy. The observed rotation speeds indicated that over 90% of the galaxy's mass must be invisible.

Why this is interesting

When astronomers measure how fast stars orbit the center of their own galaxy, they find something astonishing: outer stars are moving just as fast as inner ones, even though there seems to be hardly any visible matter out there. What is keeping them from flying off into space?

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Galactic Rotation Curves: Evidence for Dark Matter

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