Earth and Space Science
The Earth and Space Science domain tests Earth’s structure and history, plate tectonics, rocks and the rock cycle, weathering and erosion, the water cycle, atmosphere and weather, climate, oceans, the solar system, seasons, moon phases, tides, and stars. Items often ask you to distinguish long-term cycles from short-term events and to reject common misconceptions.
Core rules and concepts
Earth has a layered interior: crust, mantle, outer core, and inner core. Plate tectonics explains earthquakes, volcanoes, mountain building, and seafloor spreading. Divergent boundaries create new crust; convergent boundaries produce subduction, trenches, and mountains; transform boundaries cause faulting. The rock cycle links igneous, sedimentary, and metamorphic rocks through melting, cooling, weathering, deposition, and heat/pressure.
Weathering breaks rock in place; erosion transports sediment; deposition lays it down. The water cycle includes evaporation, condensation, precipitation, infiltration, runoff, and transpiration. The atmosphere is mostly nitrogen and oxygen; weather is short-term atmospheric conditions, while climate is long-term averages and patterns. Earth’s rotation causes day/night; revolution and axial tilt cause seasons. Moon phases result from changing angles of sunlight on the Moon as it orbits Earth; tides are mainly caused by the Moon’s gravity.
The solar system has eight planets; inner planets are rocky, outer planets are gas/ice giants. Stars produce energy by nuclear fusion; the Sun is a medium-sized star. Gravity governs orbits and galaxy structure.
Worked example
A student claims summer occurs because Earth is closest to the Sun. Evaluate this. Earth’s orbit is slightly elliptical, but closest approach does not explain opposite seasons in the two hemispheres. The cause is Earth’s 23.5° axial tilt: when the Northern Hemisphere tilts toward the Sun, sunlight strikes more directly and days are longer, producing summer there while the Southern Hemisphere has winter. The claim fails because both hemispheres would otherwise have the same season.
Traps that cost marks
Do not confuse weathering with erosion, weather with climate, or moon phases with eclipses. Seasons are not caused by distance from the Sun. In plate tectonics, recognize boundary types rather than memorizing locations. Relative dating orders events; radiometric dating gives absolute ages.