Earth & Space Science

Crust

The rocky outer layer of the Earth, very thin compared to the layers beneath it.

Mantle

A thick layer of hot, solid rock located under the Earth's crust.

Core

A large sphere of metal that forms the center of the Earth.

Plate Tectonics

The theory that pieces of the Earth's crust's outermost layer, called plates, move slowly on top of denser material.

Divergent plate boundaries

Occur when oceanic plates move apart, resulting in magma rising and forming new rock.

Convergent plate boundaries

Form when plates move toward each other and collide, creating mountains.

Transform fault boundaries

Occur when plates move sideways past each other.

Igneous rock

Forms when magma from inside the Earth cools and solidifies.

Sedimentary rock

Forms over time as sediment is layered, squeezed, and solidified.

Metamorphic rock

Forms when a rock is transformed by heat, pressure, or chemical reactions.

Water Cycle

The continuous movement of water among the oceans, atmosphere, and land.

Evaporation

The process where water converts from a liquid to a gas due to energy from the sun.

Condensation

When water vapor cools and turns back into a liquid, forming clouds.

Precipitation

Water particles falling from clouds, including rain, snow, and hail.

Earth’s Atmosphere

A mixture of gases including nitrogen, oxygen, and carbon dioxide.

Troposphere

The lowest layer of the atmosphere where weather occurs.

Stratosphere

The layer of the atmosphere where the ozone layer is found.

Mesosphere

The layer where most meteors burn up.

Thermosphere

The layer where the International Space Station orbits.

Exosphere

The layer that contains most satellites orbiting Earth.

Inner planets

Mercury, Venus, Earth, and Mars, characterized as small, dense, and rocky.

Outer planets

Jupiter, Saturn, Uranus, and Neptune, larger and more massive than inner planets.

Comets

Cosmic snowballs made up of frozen gases, rocks, and dust that orbit the Sun.

Outgassing

The process when a comet warms up and releases gases, producing a glowing head and sometimes a tail.

Mercury

The closest planet to the Sun, known for its extreme temperature fluctuations.

Venus

The second planet from the Sun, similar in size to Earth but with a thick, toxic atmosphere.

Earth

The third planet from the Sun, the only known planet to support life, with vast oceans and a diverse environment.

Mars

The fourth planet, known as the Red Planet due to iron oxide on its surface, and has the largest dust storms in the solar system.

Jupiter

The fifth planet and the largest in the solar system, known for its Great Red Spot and many moons.

Saturn

The sixth planet, famous for its stunning rings made primarily of ice particles.

Uranus

The seventh planet, known for its bluish color due to methane in its atmosphere and its unique tilt.

Neptune

The eighth and farthest planet from the Sun, known for its strong winds and deep