Why is the solar system flat?
Show answer & explanation
Answer: Angular momentum from rotation
Angular momentum from rotation ✓ — Correct! The planets formed in a rotating disk of gas and dust. As the original cloud contracted, its spin helped support material against falling straight toward the rotation axis, while contraction along that axis could continue. Collisions and cooling then helped the material settle into a disk perpendicular to the axis, and the planets inherited nearly aligned orbital planes from that disk.
Magnetic fields align planets — Wrong. Magnetic fields exist in the early solar system, but they do not flatten it. The disk comes from angular momentum being conserved as the rotating cloud collapsed.
Planets push each other flat — Wrong. Planets do not push each other flat. The disk formed before the planets did; they condensed out of an already flattened protoplanetary disk.
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