Earth Science + Astronomy

Earth Science

Study of Earth, its materials, processes, history, and place in space

Geology

Study of Earth’s solid materials

Meteorology

Study of atmosphere, weather, and climate

Oceanography

Study of oceans

Astronomy

Study of space and celestial bodies

Landforms

Natural physical features of Earth’s surface

Mountain

High elevated land

Hill

Raised land lower than a mountain

Plateau

Elevated flat land

Plain

Broad flat area

Valley

Low area between hills or mountains

Internal / Endogenic Processes

Processes that come from inside Earth

External / Exogenic Processes

Processes that happen at Earth’s surface

Weathering

Breaking down of rocks into smaller pieces

Physical / Mechanical Weathering

Breaking rocks without changing composition

Chemical Weathering

Weathering that changes rock composition

Erosion

Movement of weathered materials from one place to another

Deposition

Dropping of sediments after transport

Crust

Outermost and thinnest layer of Earth

Continental Crust

Crust under land; thicker and less dense

Granite

What is Continental Crust mostly made up of?

Basalt

What is Oceanic Crust mostly made up of?

Oceanic Crust

Crust under oceans; thinner and denser

Mantle

Thickest layer beneath the crust

Convection currents in the mantle

What drives plate movement?

Core

Center of Earth; hottest and densest layer

Outer Core

Liquid layer of iron and nickel that generates Earth’s magnetic field

Inner Core

Solid center of Earth; hottest layer

Lithosphere

Rigid outer layer made of crust and uppermost mantle

Asthenosphere

Soft, plastic layer below lithosphere

Mesosphere

Lower mantle; denser and stronger than asthenosphere

Lithosphere

In which layer do plates move and interact

Asthenosphere

Which layer allows tectonic plates to move

Mineral

Naturally occurring inorganic solid with definite chemical composition and crystal structure

Color

Visible color of a mineral

Streak

Color of a mineral in powdered form

Hardness

Resistance of a mineral to scratching

Luster

How a mineral reflects light

Cleavage

Tendency of minerals to break along flat surfaces

Fracture

Irregular breakage of minerals

Density

Mass per unit volume

Mohs Scale

Scale used to measure mineral hardness from 1–10

Talc

Softest mineral on Mohs scale

Diamond

Hardest mineral on Mohs scale

Rock

Naturally occurring solid made of one or more minerals

Igneous Rock

Rock formed from cooled magma or lava

Intrusive Igneous Rock

Igneous rock cooled inside Earth

Extrusive Igneous Rock

Igneous rock cooled on Earth’s surface

Sedimentary Rock

Rock formed from accumulated sediments

Metamorphic Rock

Rock formed when existing rocks change due to heat and pressure

Rock Cycle

Continuous transformation of rocks from one type to another

Fossil

Preserved remains, traces, or impressions of ancient organisms

Body Fossil

Actual remains of organisms

Trace Fossil

Evidence of organism activity

Mold Fossil

Hollow impression left in rock

Cast Fossil

Fossil formed when a mold fills with minerals

Fossil Formation

Process of fossil creation through burial and mineral replacement

Plate Tectonics

Theory explaining movement of Earth’s lithospheric plates

Tectonic Plates

Large moving sections of the lithosphere

Convection Currents

Movement in mantle caused by heat that drives plate movement

Plate Boundaries

Edges where tectonic plates meet

Divergent Boundary

Boundary where plates move apart

Convergent Boundary

Boundary where plates move toward each other

Transform Boundary

Boundary where plates slide past each other

Rift Valley

Landform formed when tectonic plates move apart

Mid-Ocean Ridge

Underwater mountain chain formed at divergent boundaries

Trench

Deep depression in ocean floor formed at convergent boundaries

Atmosphere

Layer of gases surrounding Earth

78% Nitrogen, 21% Oxygen, 1% Other Gases

Mixture of Gases in the Atmosphere

Troposphere

Lowest atmospheric layer where weather occurs

Stratosphere

Atmospheric layer containing the ozone layer

Mesosphere

Coldest atmospheric layer where meteors burn up

Thermosphere

Very hot atmospheric layer where auroras occur

Exosphere

Outermost atmospheric layer

Weather

Short-term atmospheric conditions

Temperature

Measure of how hot or cold the air is

Humidity

Amount of water vapor in air

Air Pressure

Force exerted by air on Earth’s surface

Wind

Movement of air from high pressure to low pressure

Precipitation

Water falling from clouds

Climate

Long-term average weather of an area

Latitude

Distance north or south of the equator

Altitude

Height above sea level

Climate Zones

Regions with similar climate patterns

Greenhouse Effect

Natural warming of Earth caused by heat-trapping gases

Greenhouse Gases

Gases that trap heat in Earth’s atmosphere

71%

What percentage of the Earth’s surface is water?

Water Cycle

Continuous movement of water on Earth

Evaporation

Process where liquid water turns into water vapor

Condensation

Process where water vapor cools into droplets

Precipitation

Water falling from clouds as rain, snow, etc.

Collection

Water gathering in rivers, lakes, and oceans

Infiltration

Water entering the ground

Ocean

Large body of saltwater covering most of Earth’s surface

River

Large flowing body of freshwater

Lake

Large inland body of standing water surrounded by land

Stream

Small flowing body of water

Groundwater

Water stored beneath Earth’s surface

Water Pollution

Contamination of water by harmful substances