Why are there seasons on Earth?
Show answer & explanation
Answer: Axial tilt changes sunlight angle
Axial tilt changes sunlight angle ✓ — Correct! Earth's axis tilts 23.5° relative to its orbital plane. When the Northern Hemisphere tilts toward the sun, it receives more direct sunlight (longer days, warmer—summer). When tilted away, sunlight hits at oblique angles (shorter days, colder—winter). Southern Hemisphere experiences opposite seasons. Solstices = maximum tilt; equinoxes = neutral. Distance from sun isn't the cause!
Earth's orbit speed varies — Wrong. Orbital speed varies slightly (Kepler's laws), but seasons result from axial tilt changing how directly sunlight hits different hemispheres.
Sun's brightness fluctuates — Wrong. The sun's output is remarkably stable. Seasons occur because Earth's tilted axis causes varying sunlight angles throughout the year.
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