Earth and Space Science (Grades 9–12)
What the test targets
Earth and Space Science (9–12) tests geology, plate tectonics, rocks and minerals, weathering/erosion, atmosphere and climate, oceans, astronomy, and Earth history. Items emphasize systems, evidence, and scale.
Core rules
- Plate tectonics explains earthquakes, volcanoes, mountain belts, and seafloor spreading; evidence includes magnetic stripes, seismic patterns, and fossil/rock matching.
- The rock cycle is a web, not a linear sequence; rocks change by melting, cooling, weathering, compaction, and metamorphism.
- Climate vs weather: climate is long-term patterns; weather is short-term state. Seasons result from axial tilt, not distance from the Sun.
- Earth's layers are inferred from seismic waves: P waves travel through solids and liquids; S waves cannot pass through liquids, creating a shadow zone.
- Astronomy: solar system formation from a nebula; stellar life cycles depend on mass; universe expansion evidenced by redshift.
- Use deep time and systems thinking (feedback, reservoirs, fluxes).
Worked example
A question asks why S waves are not recorded on the opposite side of Earth from an earthquake. Reasoning: S waves are transverse and cannot travel through liquid; the outer core is liquid, so S waves are blocked and a shadow zone appears. P waves refract through the core and are recorded in some far regions. The answer should name wave type, material state, and shadow zone-not just 'the core stops them.'
Traps
- Explaining seasons by Earth's distance from the Sun.
- Treating the rock cycle as one-way.
- Confusing climate and weather.
- Reversing the order of geologic time or ignoring scale.