Focus on the BIG Ideas
Chemistry and physics describe the laws governing matter, energy, and their interactions. Earth and space science explores how these rules play out on Earth and beyond—in the solar system, the Milky Way galaxy, and the universe.
Earth is in constant motion, not only in relation to the sun and the Milky Way, but internally as well. Vigorous convection occurs at all levels within the planet, including the mantle, the oceans, and the atmosphere. Earth's high level of geologic activity is the result of two energy sources: the sun and the decay of underground radioactive elements. Sunlight powers the water cycle, and in turn the weathering and erosion processes that tear down land. Radioactivity drives the convection currents in Earth's mantle that control plate motions and create new land. These two processes are in constant battle over control of Earth's surface.
The universe began with the big bang 13.7 billion years ago. Since then, the universe has expanded at the speed of light or faster, and is now tens of billions of light years across. The universe contains hundreds of billions of galaxies, each of which can contain hundreds of billions of stars.
Stars Over Arches National Park, Utah ▸ Both Earth science and space science are represented in this time exposure photo, taken at night. Stars appear as long curved trails of light circling the north celestial pole. The apparent motion of the stars is due to Earth's rotation on its axis.
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