Earth and Space Science Flashcards

Vocabulary flashcards for Earth and Space Science review.

Age of Earth

The estimated age of Earth, approximately 4.6 billion years ago.

Determining Age of Earth

Scientists use landforms, fossils, and radiometric dating as major types of evidence.

Formation of Sedimentary Rock

The process where sediment settles and becomes compacted into layers, with the youngest layers on top and the oldest at the bottom.

Fossils

Remains or evidence of dead organisms, commonly found in sedimentary rock.

Relative Age

Determining the age of objects by comparing rock layers and fossils.

Radiometric Dating

Provides the exact age of objects by using radioactive isotopes.

Radioactive Isotopes

Versions of elements that turn into another element by losing a proton.

Half-life

The amount of time it takes for half of an isotope's atoms to change into another element.

Solar System

Made up of the sun and all objects that orbit the sun.

Sun

The largest object in the solar system; its gravity keeps all other objects orbiting around it.

Terrestrial Planets

Planets closest to the sun with rocky surfaces.

Gas Giants

Larger planets farther from the sun with gaseous surfaces.

Moon

Natural object in space that orbits a planet.

Asteroid

A large, irregularly shaped chunk of rock, mostly found in a band between the terrestrial planets and gas giants.

Comets

Made up of frozen gases and dust particles, usually smaller than asteroids.

Revolution

The act of the Earth completing one revolution around the sun every 365 days.

Rotation

The act of Earth spinning on its axis, completing on rotation every 24 hours.

Eclipse

Caused by the positions of the sun and moon in relation to Earth.

Solar Eclipse

The moon blocks sunlight from reaching Earth.

Lunar Eclipse

Earth blocks sunlight from reaching the moon.

Tides

Daily rises and falls of ocean levels.

High Tide

When the ocean reaches its highest point on the shore.

Low Tide

When the ocean reaches its lowest point on the shore.

Spring Tides

Extra high and extra low tides when the sun is in line with the moon.

Neap Tides

Only minor differences in high and low tides when the sun and moon are perpendicular to each other.

Universe

The total of all matter and energy that exists.

Star

A ball of gas that produces its own light and heat.

Constellation

A recognized pattern of stars in the night sky.

Galaxy

A massive group of stars, gas, dust, and dark matter held together by gravity.

Big Bang Theory

The theory that all matter and energy was once in an area the size of an atom, which exploded, causing the universe to rapidly expand outward.

Nebula

Cloud of gas and dust where a star forms.

Protostar

A forming star.

Main Sequence Star

A star that spends most of its life fusing hydrogen atoms into helium atoms, releasing heat and light.

White Dwarfs

Stars that are close to dying out.

Supergiant Stars

Massive protostars that die in a sudden explosion.

Black Hole

A possible result of the death of a supergiant.

Crust

Earth's outermost layer of rock consisting of oceanic crust and continental crust.

Basalt

Dense, dark finely textured rock that mostly consists of oceanic crust.

Continental Crust

Forms the continents, mainly consists of granite, which is a lighter, less dense rock with larger crystals than those found in basalt.

Mantle

The boundary of hot rock underneath the crust largely made of silicate rocks that contain lots of iron, nickel, and magnesium.

Lithosphere

Formed by the uppermost part of the mantle and the crust in a rigid layer.

Asthenosphere

A soft layer of the mantle where material can flow freely.

Core

Consists of a molten, liquid outer core and a solid, dense inner core, made of metals like iron and nickel.

Tectonic Plates

Earth's crust comes together in sections, floats on the mantle by means of convection currents.

Convection Currents

Hot currents of molten rock that cause the tectonic plates above them to move one or two centimeters each year.

Continental Shelves

Gently sloping, shallow sections of the ocean floor that extend outward from the edge of a continent.

Ocean Basins

Vast geologic regions below sea level that cover nearly 75% of Earth's surface containing features such as deep-sea trenches and mountain-like ocean ridges.

Transform Boundary

Boundary where one plate is sliding past another.

Divergent Boundary

Boundary where two plates are pulling apart.

Convergent Boundary

Boundary where two plates are colliding with each other.

Fold Mountains

Created when the collision of two plates squeezes the two plates together.

Trenches

Created when one plate is forced down into the mantle beneath a second plate.

Volcano

A weak spot in the crust where molten rock is sent to the surface.

Lava

Molten rock sent to Earth's surface.

Earthquakes

Formed by the shifting and breaking of the surface rocks.

Fault

The break in the crust where earthquakes can occur.

Earth's Atmosphere

The envelope of gases that surrounds the planet.

Troposphere

The lowest region of the atmosphere, sustains life and where all weather occurs.

Stratosphere

Temperatures increase with height and ozone, a form of oxygen, is concentrated here.

Mesosphere

Rapid fall in temperature with height and temperature very low.

Thermosphere

Rapid increase in temperature with height due to influx of solar energy.

Ionosphere

Electrified region that contains large concentrations of ions and free electrons and important for radio wave propagation.

Exosphere

Merges into the regions of Earth's magnetic field, radiation belt, and outer space.

Greenhouse Effect

The process by which gases in the atmosphere trap solar energy.

Greenhouse Gases

Greenhouse gases including water vapor, carbon dioxide, and methane.

Global Warming

A gradual increase in the temperature of Earth's atmosphere that can lead to climate change.

Ozone

Works as a protective blanket in the stratosphere, filtering harmful ultraviolet rays from the sun before they reach Earth.

Chlorofluorocarbons (CFCs)

A group of chlorine compounds that are the main culprit for the thinning ozone layer.

Weathering

The process of breaking down or dissolving minerals and rocks on Earth's surface.

Erosion

The process by which water, wind, and gravity transport bits of rocks and minerals away.

Chemical Weathering

Materials that make up rocks and soil are changed by chemical means.

Mechanical Weathering

Causes rocks to crumble.

Freeze-thaw

Water enters cracks in the rock and expands as it freezes, placing pressure on the rocks around it, causing the rocks to crack and split over time.

Wind Abrasion

The wind carries dust, sand, and other small grit particles that repeatedly strike the surface of rocks, resulting in a gradual wearing away of the rock.

Wind

The movement and flow of gases on Earth's surface due to the uneven heating of the surface by the sun.

Low Pressure System

Warm equatorial air that rises higher into the atmosphere and then flows toward the poles.

High Pressure System

Dense, cooler air that flows toward the equator to replace the heated air.

Front

The boundary between a high pressure area and a low pressure area.

Prevailing winds

Winds that regularly blow from a single direction over a specific area of Earth.

Convergence Zones

Areas where prevailing winds meet.

Coriolis Effect

Earth's rotation generates a circulation pattern that makes wind systems twist counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Ocean Currents

Streams of water running through a larger body of water set in motion by a variety of factors.

Upwelling

When winds push surface water away from the shore, deep currents of cold water rise to take its place.

Gulf Stream

Origins in the tropical Caribbean Sea and influences weather patterns all over the globe.

El Nino

A phenomena, warm-water currents sometimes displace the cold Humboldt Current along the west coast of South America.

Coral Reefs

Created by colonies of tiny coral animals that produce a hard structure around their soft bodies.

Zooxanthellae

Llive in the bodies of coral animals and provide them with food produced by photosynthesis.

Carbon Cycle

System involving living things and the nonliving matter in Earth's crust, oceans, and atmosphere where carbon is transferred from one part of the environment to another.

Nitrogen Cycle

Dependent upon bacteria, nitrogen moves from the air to the soil, into living things, and back into the air.

Oxygen Cycle

Describes the movement of oxygen within the atmosphere, organisms, and nonliving matter on Earth's crust. The driving force is photosynthesis.

Water cycle

Describes the continuous process of transporting water from the oceans to the atmosphere, then to the land, and then returning it to the oceans.

Natural Hazard

The threat of a natural event that can have a negative effect on organisms and the environment.

Mitigation

An effort to reduce the loss of property and life by lessening the impact of the disaster.

Renewable Resources

Those that will never run out, either naturally or through proper management.

Nonrenewable resources

Those that will eventually run out because they have a finite supply.

Fossil Fuels

Formed slowly, over millions of years, from the decomposition of plants and animals.

Sustainable

Able to be maintained over time at an acceptable level.