3. Recap: Earth & Space Science Essentials

Earth & Space Science is the smallest strand, but its cycles and patterns are very testable.

The must-knows:

• Rock cycle: igneous (cooled magma), sedimentary (compacted layers, often with fossils), and metamorphic (changed by heat and pressure) rocks transform into one another.
• Water cycle: evaporation → condensation → precipitation → collection, driven by the Sun.
• Plate tectonics: Earth's plates move, building mountains and causing earthquakes and volcanoes at their boundaries.
• Earth's layers: crust, mantle, outer core (liquid), inner core (solid).
• Day, seasons, Moon: day/night come from Earth's rotation; seasons come from Earth's tilt, not its distance from the Sun; Moon phases come from its orbit.

Common mix-up: seasons are caused by the Earth's tilt (which hemisphere leans toward the Sun), not by how close Earth is to the Sun.