Key concepts: Earth and space science

The following are key concepts/big ideas in earth and space science:

The Earth is a single system with four dynamically interconnected 'spheres'

These are the geosphere (rock of the crust, mantle, and core), the hydrosphere (solid, liquid, and gaseous water), the atmosphere (gases of the air) and the biosphere (living organisms).

The Earth works in cycles

The tectonic, rock and water cycles constantly reshape the surface of the Earth. Bio-geochemical cycles move the elements essential for life. These cycles also balance and regulate the Earth’s climate.

All parts of the Earth system are constantly changing

Earth systems interact with themselves, and with the Sun, Moon and the rest of the solar system and universe.

Critical thresholds can be reached through natural variations in cycles and by human activity.

Earth is dynamically part of the solar system and beyond

The solar system comprises of objects that are gravitationally bound to the Sun. The solar system and all other planetary systems are formed during the life cycle of stars which have been born, lived and died in giant cycles since the Big Bang.

Distance/time scales in Earth and space systems vary greatly

In all Earth and space system processes and cycles, time scales can range from micro-seconds to billions of years, and distance scales range from microns to thousands of light years.

• Key concepts: Science | Biology | Physics | Chemistry
• Achievement objectives: Earth and space science

Last updated December 3, 2010

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