What specific observation concerning galactic rotation curves provided early evidence for dark matter?

Answer

Outer stars orbit at the same speed as inner stars.

Observations showed that stars in the outer regions of spiral galaxies maintain a consistent high orbital speed, implying that an unseen massive halo provides the necessary extra gravitational pull.

What specific observation concerning galactic rotation curves provided early evidence for dark matter?

#Videos

Dark Matter Explained | Cosmology 101 Episode 7 - YouTube

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