Cosmos

Learning path · Beginner

The Restless Planet

Earth never sits still. Follow the forces that move continents, raise volcanoes, stir the oceans and drive the weather.

7 lessons About 28 minutesPlanet Earth

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Lessons

  1. 1

    Planet Earth

    Inside the Earth

    Beneath your feet lie 6,370 kilometres of rock and metal, hotter than the surface of the Sun at the centre. No one has drilled even one percent of the way down.

    4 min read 4-question quiz

  2. 2

    Planet Earth

    Plate Tectonics and Earthquakes

    The continents are moving at the speed your fingernails grow. Where they collide, mountains rise; where they grind past each other, the ground shakes.

    4 min read 4-question quiz

  3. 3

    Planet Earth

    Volcanoes

    There are about 1,350 potentially active volcanoes on land, and far more under the sea. They built the continents, made the air breathable and can bury cities in hours.

    4 min read 4-question quiz

  4. 4

    Planet Earth

    Rocks, Minerals and Fossils

    Every pebble is a page in a 4.5-billion-year story. Learn to read the three kinds of rock, the crystals they are made of, and the dead things trapped inside them.

    4 min read 4-question quiz

  5. 5

    Planet Earth

    The Oceans

    Water covers 71 percent of the planet, mostly in darkness and under crushing pressure. We have mapped the surface of Mars in more detail than our own seafloor.

    4 min read 4-question quiz

  6. 6

    Planet Earth

    The Atmosphere

    The air is a thin shell of gas, mostly nitrogen, that keeps us warm, shields us from radiation and burns up the rocks that fall from space. Here is how it is built.

    4 min read 4-question quiz

  7. 7

    Planet Earth

    Weather and Climate

    Weather is what the sky does today; climate is what it tends to do over decades. Both are driven by one thing: the Sun heating a spinning, watery planet unevenly.

    4 min read 4-question quiz