Earth Science 11 – Review: Formation of Universe and Earth Concepts (Vocabulary Flashcards)

Vocabulary flashcards covering formation of the universe, solar system, geologic time, Earth’s early history, planetary habitability, Earth’s subsystems and layers, and rock types with key processes.

Big Bang Theory

The widely accepted theory that the universe began ~13.8 billion years ago from a hot, dense singularity and has since expanded; evidence includes CMBR, redshift, and light-element abundances.

singularity

A hot, dense point from which the universe originated in the Big Bang model.

Cosmic Microwave Background Radiation (CMBR)

Faint radiation leftover from the early universe; key evidence for the Big Bang.

Redshift

The apparent increase in wavelength of light from distant galaxies, indicating they are moving away and the universe is expanding.

Abundance of light elements

Predominance of hydrogen and helium produced in the early universe, supporting Big Bang nucleosynthesis.

Steady State Theory

Alternative to the Big Bang proposing the universe has no beginning or end, with continuous creation of matter to keep density constant.

Inflation Theory

Extension of the Big Bang that explains a rapid, exponential expansion of the universe in a fraction of a second after its origin.

Nebular Hypothesis

Kant and Laplace proposal that the Solar System formed from a collapsing nebula ~4.6 billion years ago, with the Sun at the center and planets forming from the disk.

Sun

The central star of the Solar System around which the planets orbit.

Mercury

Terrestrial planet; smallest; has little to no atmosphere.

Venus

Terrestrial planet; hottest; thick atmosphere.

Earth

Terrestrial planet; habitable; contains liquid water and life.

Mars

Terrestrial planet; the Red Planet; thin atmosphere.

Jupiter

Gas giant; largest planet; features the Great Red Spot.

Saturn

Gas giant with a prominent ring system.

Uranus

Ice giant with an extreme axial tilt; blue-green color from methane.

Neptune

Ice giant with strong winds; farthest recognized planet in the notes.

Asteroids

Rocky or metallic bodies mostly found in the asteroid belt.

Meteoroids

Small space rocks that originate from comets or asteroids or other planets.

Comets

Bodies composed of ice, rocks, and dust that develop tails when near the Sun.

Kuiper Belt

Region beyond Neptune; source of short-period comets.

Asteroid Belt

Region between Mars and Jupiter; source of asteroids.

Oort Cloud

Distant region beyond the Kuiper Belt; source of long-period comets.

Geologic Time Scale

Hierarchical system of time units used in geology: eon, era, period, epoch.

Eon

Largest subdivision of geologic time; lasts hundreds of millions to billions of years.

Era

Subdivision of an eon; lasts tens to hundreds of millions of years.

Period

Subdivision of an era; lasts tens of millions of years.

Epoch

Subdivision of a period; lasts millions of years.

Hadean Eon

4.6–3.8 billion years ago; intense meteorite bombardment; formation of oceans and atmosphere; Theia impact forming the Moon.

Archean Eon

3.8–2.5 billion years ago; methane-rich atmosphere with little oxygen; oceans; formation of continents; oldest rocks like stromatolites and apex chert.

Proterozoic Eon

2.5 billion years ago to 542 million years ago; atmospheric oxygenation; origin and diversification of eukaryotic life; appearance of multicellular life.

Phanerozoic Eon

Eon characterized by visible life; includes Paleozoic, Mesozoic, and Cenozoic.

Paleozoic Era

Early life with marine shells, amphibians; reptiles appear; trilobites common.

Mesozoic Era

Continents drifted; dinosaurs; major plant and animal changes; ends with mass extinctions.

Cenozoic Era

Mountains uplifted; mammals rise; development of modern fauna and flora; Ice Ages; Homo genus appears.

Goldilocks Zone

Habitable zone around a star where conditions may allow liquid water on a planet’s surface.

Liquid water

Essential requirement for life as we know it; presence on a planet helps define habitability.

Right distance to the Sun

Optimal solar distance to maintain liquid water and stable climate.

Plate tectonics

Movement of Earth's lithospheric plates that recycles materials and shapes the crust.

Right size

Sufficient planetary size to retain an atmosphere and sustain geologic activity.

Right gravity

Gravity strong enough to hold an atmosphere and support life processes.

Atmosphere

Layer of gases surrounding Earth; protects and sustains life.

Moon (Luna)

Earth’s natural satellite influencing tides and climate stability.

Magnetosphere

Magnetic field that shields the planet from harmful solar radiation.

Energy

Sustaining energy input from the Sun to drive climate and life processes.

Time

Sufficient time for chemical evolution and complex life to develop.

Geosphere

The solid Earth: rocks, magma, and soil.

Atmosphere (Earth layer)

Layer of gases surrounding the planet.

Hydrosphere

All of Earth’s water: oceans, rivers, groundwater, etc.

Biosphere

All living organisms on Earth.

Crust

Outermost Earth layer; oceanic crust (5–10 km, basalt) is thinner; continental crust (30–70 km, granite) is thicker.

Mantle

Largest Earth layer (up to ~2900 km); molten rock and convection currents; includes upper and lower mantle.

Core

Earth’s center: outer core is liquid; inner core is solid.

Mohorovičić discontinuity

Boundary between crust and upper mantle.

Gutenberg discontinuity

Boundary between lower mantle and outer core.

Lehmann discontinuity

Boundary between outer and inner core.

Weathering

Natural breakdown of rocks and minerals on Earth’s surface into smaller pieces.

Erosion

Movement of rock, soil, or sediment by wind, water, or ice after weathering.

Magmatism

Movement or activity of magma; molten rock formed by melting existing rocks under high temperature/pressure.

Igneous rocks

Rocks formed from cooling and solidification of molten material; extrusive (volcanic) or intrusive (plutonic).

Sedimentary rocks

Rocks formed from accumulation and compression of sediments; often contain fossils.

Lithification

Process by which sediments become sedimentary rocks via compaction and cementation.

Metamorphic rocks

Rocks formed from pre-existing rocks transformed by heat or pressure.

Metamorphism

Transformation of a parent rock into a new mineralogically/structurally different rock due to heat/pressure.