Comprehensive Study Notes on Earth Science and the Universe ((FLASHCARDS)

Definitions and Fundamental Disciplines of Earth Science

Earth Science: The comprehensive study of our Earth.
Geology: The specific study of the materials and processes that operate beneath and upon the surface of the Earth.
Astronomy: The study of the universe, the origin of planets, and the various members of the solar system.
Oceanography: The study of the composition and movements of seawater, coastal processes, topography, and marine life.
Meteorology: The study of the atmosphere and the elements that produce weather.
Cosmology: The study of the universe as a whole, including its properties, structure, and evolution.

Origin and Evolution of the Universe

The Big Bang: Between $10$ and $15$ billion years ago, the universe began with a primordial explosion known as the Big Bang.
Initial State: All energy and matter in the universe were originally compressed into an extremely hot and dense state.
Timeline of Development:
- Birth: Approximately $13.7$ billion years ago, the universe began with a cataclysmic explosion and has continued to expand, cool, and evolve into its current state.
- 3 Minutes Post-Explosion: Great quantities of helium and hydrogen were created.
- 3 Million Years Post-Explosion: Huge clouds of matter began to condense as temperatures decreased sufficiently to allow clumps of matter to collect.
- 200 Million Years Post-Explosion: Formation of the first galaxies.
Etymology of "Universe": Derived from the French and Latin word universum, meaning space and time (spacetime).
Synonym: The universe is also referred to as the cosmos.
Galactic Examples:
- Milky Way
- Large Magellanic Cloud
- Andromeda
- Cigar Galaxy
- Tadpole Galaxy

Theories on the Origin of the Universe

Big Bang Theory: Asserts that all energy and matter were compressed into a hot, dense state. Around $13.7$ billion years ago, it expanded and cooled from a cataclysmic explosion.
Creationist Theory: States that God, the Supreme Being, created the entire universe out of nothing.
Oscillating Theory: Proposed by Russian-born U.S. cosmologist George Gamow. It suggests that the expansion of the universe will eventually halt and then collapse back to its original form.
Steady State Theory: Claims the universe has always been the same since the beginning and will remain in its present state for eternity. It posits that new galaxies appear as a result of other galaxies drifting away.
Our Expanding Universe: Evidence shows the universe is still expanding based on the Doppler red shift in the light received from distant sources. This indicates an increasing distance between Earth and other galaxies and suggests the expansion is occurring slowly.

The Solar System and Its Members

Solar System Composition: Made up of various celestial bodies, which are natural objects in the sky. These include:
- The Sun: A star located at the center of the Solar System that produces its own light and heat.
- Planets
- Satellites
- Comets: Described as "cosmic snowballs" or frozen gases, rock, and dust. When frozen, they are approximately the size of a small town. As they approach the Sun, they heat up and spew dust.
- Asteroids
- Meteoroids, Meteors, and Meteorites

Characteristics of the Planets

Mercury:
- Nearest planet to the Sun.
- Has no moons.
- Rotation: $58$ days.
- Revolution: $88$ days.
- Temperature range: $445^\circ C$ to $-184^\circ C$ .
Venus:
- Hottest planet, reaching temperatures of $449^\circ C$ .
- Known as the "Morning Star" or "Evening Star."
- Has no moons.
- Rotation: $243$ days.
- Orbit (Revolution): $224$ days.
Earth:
- The third planet from the Sun and the only known planet to support life.
- Has $1$ moon.
- Rotation: $24$ hours.
- Orbit (Revolution): $365$ days.
- Life-supporting factors: Sufficient oxygen in the atmosphere and water on the surface.
Mars:
- Most Earth-like planet in the Solar System.
- Has $2$ moons.
- Atmosphere: Mainly Carbon Dioxide ( $CO_2$ ).
- Features: Contains the biggest volcano in the Solar System; ice exists on both the north and south poles.
- Rotation: More than $24$ hours.
- Revolution: $686$ days.
Jupiter:
- A gas giant and the largest planet; all other planets could fit inside it.
- Has $63$ moons.
- Rotation: $10$ hours.
- Orbit (Revolution): Almost $12$ years.
Saturn:
- A gas giant famous for its rings made of ice and rocks.
- Has $33$ moons.
- Rotation: $10$ hours.
- Revolution: More than $29$ years.
Uranus:
- A light blue gas giant.
- Color: Methane gas absorbs red light, giving the planet its blue hue.
- Axis: Extremely tilted.
- Has $27$ moons.
- Rotation: $18$ hours.
- Revolution: $84$ years.
Neptune:
- A blue gas giant with an atmosphere composed of methane.
- The farthest planet from the Sun.
- Has $13$ moons.
- Rotation: $16$ hours (listed as $14$ in planet summary table).
- Orbit (Revolution): More than $164$ years.

The Earth and the Moon

The Moon: Earth's only natural satellite. Its rotation is synchronized with Earth's, taking $24$ hours to rotate on its axis.
Phases of the Moon: Includes First Quarter, Crescent Moon, Full Moon, and Third Quarter.
Earth's Location:
- Position: Third planet.
- Distance from Sun: $93$ million miles (Light takes $500$ seconds to travel this distance).
- Goldilocks Zone: The habitable zone where temperature ranges from $-15^\circ C$ to $115^\circ C$ . Planets too close (Mercury/Venus) are dry and lifeless; those too far (Uranus/Neptune) are cold and dark.
- Asteroid Belt: Located between Mars and Jupiter; it helps prevent planetary collisions.

Earth's Vital Systems and Characteristics

Atmosphere: A gaseous layer that regulates surface temperature.
- Composition: $78\%$ Nitrogen ( $N_2$ ).
- Photo-dissociation: A decomposition reaction in the stratosphere where solar radiation breaks down ozone ( $O_3$ ) into elemental oxygen ( $O$ ) and diatomic oxygen ( $O_2$ ). This process absorbs high-energy radiation and converts it to low-energy radiation.
- Greenhouse Gases: Without them, the Earth would be more than $60^\circ F$ colder.
- Atmospheric Layers:
  - Troposphere: $20\,km$
  - Stratosphere: $50\,km$
  - Mesosphere: $85\,km$
  - Thermosphere: $690\,km$
  - Exosphere: $10,000\,km$
Size and Mass: Earth's mass provides the gravitational pull necessary to sustain a gaseous atmosphere and keep the Moon in its orbit.
Earth's Magnetic Field: Acts like a big ball magnet.
- Mechanism: Movement of liquid iron and nickel in the outer core (caused by Earth's rotation) creates an electric current that produces the magnetic field.
- Function: Deflects harmful solar winds and radiation that could destroy the ozone layer.
- Magnetosphere: Extends about $65,000\,km$ into space.
- Orientation: Geographic North is Magnetic South; Geographic South is Magnetic North.
Presence of Water: $71\%$ of the surface is covered with water ( $H_2O$ ).
- Forms: Exists as gas (forming clouds) and liquid (oceans and lakes).
- Benefits: Right amount of water provides a cooling effect and acts as a solvent to transport materials in and out of cells.
Nutrients: Essential for building and maintaining organisms. The inner planets and moons share general chemical components, including Carbon ( $C$ ), Hydrogen ( $H$ ), Nitrogen ( $N$ ), Oxygen ( $O$ ), Phosphorus ( $P$ ), and Sulfur ( $S$ ) (CHNOPS).

Earth Surface and Geography

Philippines Position: $12.8797^\circ N, 121.7740^\circ E$ .
Coordinate Systems:
- Latitude: Horizontal lines measuring distance North or South from the Equator ( $0^\circ$ ).
- Longitude: Vertical lines measuring distance East or West from the Prime Meridian.
Climatic Zones:
- Polar Zone: Cold ( $66.5^\circ$ to the poles).
- Temperate Zone: Warm/Cold ( $23.5^\circ$ to $66.5^\circ$ ).
- Tropics: Hot (between the Tropic of Cancer at $23.5^\circ N$ and Tropic of Capricorn at $23.5^\circ S$ ).

Geological Activity and Faults

Fault: A break or fracture in the Earth's crust along which significant movement has taken place, often causing a crack in the surface.
Seismic Energy: The energy released during an earthquake.
Stress and Strain:
- Stress: The force exerted per unit area.
- Strain: The physical change resulting from that force.
Types of Stress:
- Tensional: Crust lengthens (thins); plates pull away from each other.
- Compressional: Crust shortens.
- Shear: Crust slides past another piece of crust.
Fault Categories:
- Normal Fault: A dip-slip fault where the block above moves downward relative to the block below (caused by tensional stress).
- Strike-slip Fault: Rocks on either side slip past each other sideways with little vertical motion (caused by shear stress).
- Sinistral: Left-lateral strike-slip fault.
- Dextral: Right-lateral strike-slip fault.
5 Main Parts of a Fault:
1. Fault plane
2. Fault trace
3. Fault scarp
4. Hanging wall
5. Footwall
Focus (Hypocenter): The underground point of origin where rocks break and move.
Epicenter: The point on the Earth's surface directly above the focus; the site of the most violent shaking.
Earthquake Damage: Includes landslides, building damage, and liquefaction.
Pacific Ring of Fire: A horseshoe-shaped belt of volcanoes and seismic activity. It is a major area of subduction zones where convergent plate boundaries force one tectonic plate beneath another, creating magma and volcanoes.

Earth's Origin: History and Scientific Development

Ancient Beliefs: Civilization used myths to explain Earth (e.g., Greek mythology, Egyptian stories, Filipino indigenous beliefs, Biblical creation).
Scientific Revolution (1600s–1700s): Shifted focus toward observation, mathematics, and experiments. Astronomers discovered planets move by natural laws rather than supernatural forces.
Nebular Hypothesis Development:
- Immanuel Kant (1755): Proposed the Solar System formed from a huge cloud of gas and dust (Nebula).
- Pierre-Simon Laplace (1796): Improved the idea, suggesting the cloud rotated, gravity pulled material inward, the spinning cloud flattened into a disk, and the Sun formed at the center while remaining materials became planets.
Nebular Hypothesis Process: Approximately $4.6$ billion years ago, the Solar System formed from a giant rotating cloud (solar nebula). Steps include:
1. Self-gravity contracts gas cloud.
2. Conservation of angular momentum pulls cloud into a disk.
3. Disk rotates and a central mass (proto-Sun) forms.
4. Centrifugal force balances gravitational forces, forming rings.
5. Rings form into planets.
Planetesimal Formation (Accretion Process):
- Stage 1: Tiny dust particles in the nebula collide and stick together (accretion).
- Stage 2: Dust grains become larger rocks.
- Stage 3: Gravity strengthens, attracting more materials to form planetesimals.
- Stage 4: Planetesimals collide frequently, mostly merging into larger bodies.
- Stage 5: Over millions of years, protoplanets evolve into the current planets, including Earth.
Timeline summary:
- 4.6 billion years ago: Giant nebula existed; gravity caused collapse; solar disk formed.
- Around 4.5 billion years ago: Sun began forming; dust orbited; small particles stuck together; Protoplanets and Earth formed.
Scientific Evidence:
- Meteorites: Contain ancient materials from the solar system's birth.
- Radioactive Dating: Determines Earth's age to be approximately $4.54$ billion years.
- Telescopes: Observation of young stars surrounded by dust disks.
- Space Missions: Study of asteroids and comets that preserve early solar system clues.

Highest vs. Tallest Mountains

Highest Mountain: The peak furthest away from sea level.
Tallest Mountain: The peak furthest away from the base of the mountain.

Comparison: Nebular vs. Planetesimal

Nebular Hypothesis: Explains the start of the whole Solar System; starts with a giant nebula and a rotating disk where the Sun forms first.
Planetesimal Formation: Explains how individual planets formed; starts with dust particles sticking together through accretion.