"What Keeps Galaxies from Falling Apart?"

🌌 Why Do Galaxies Spin?

Galaxies spin due to the conservation of angular momentum. During the early stages of the universe, clouds of gas and dust began to collapse under gravity. As they collapsed, they started spinning — just like an ice skater spins faster when they pull in their arms. Over billions of years, this spin formed spiral galaxies.

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🔁 How Fast Do Galaxies Spin?

Milky Way Galaxy (our galaxy):

Spins at about 828,000 km/h (514,000 mph) at the Sun's location.

Takes about 225–250 million years to complete one rotation (called a galactic year).

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🌠 Interesting Facts:

Spiral galaxies (like the Milky Way) show flat rotation curves, meaning stars near the edges move almost as fast as those near the center. This is one of the key pieces of evidence for dark matter.

The rotation is not like a solid disk; stars orbit at different speeds based on their distance from the center, but in unexpected ways due to unseen mass (dark matter)