Junior Cycle 3rd-Year Science Notes: Strand Two — Earth and Space

Junior Cycle 3rd-Year Science Notes: Strand Two — Earth and Space

Water and Carbon Cycles

  • Water Cycle:

    • Processes: Evaporation, Condensation, Precipitation, Runoff, Infiltration.

    • Importance: Distributes water, supports ecosystems, and regulates Earth’s climate.

      Water Cycle

  • Carbon Cycle:

    • Processes:

      • Photosynthesis: Plants take in carbon dioxide (CO₂) and convert it into glucose using sunlight.

      • Respiration: Animals and plants release CO₂ back into the atmosphere by breaking down glucose for energy.

      • Decomposition: Dead organisms are broken down by decomposers, releasing CO₂ and methane into the atmosphere.

      • Combustion: Burning fossil fuels and biomass releases stored carbon as CO₂.

      • Ocean Uptake: Oceans absorb CO₂, where it can form carbonates used by marine organisms or remain dissolved.

    • Importance: Regulates Earth’s temperature, supports life through its role in ecosystems, and balances carbon between the atmosphere, oceans, and biosphere.

      The Carbon Cycle - Farm Carbon Toolkit

  • Nitrogen Cycle:

    • Processes:

      • Nitrogen Fixation: Atmospheric nitrogen (N₂) is converted into ammonia (NH₃) by bacteria or lightning.

      • Nitrification: Ammonia is converted into nitrites (NO₂⁻) and then nitrates (NO₃⁻) by soil bacteria.

      • Assimilation: Plants absorb nitrates and use them to build proteins and DNA.

      • Ammonification: Decomposers convert organic nitrogen from dead organisms back into ammonia.

      • Denitrification: Bacteria convert nitrates back into atmospheric nitrogen (N₂).

    • Importance: Provides essential nutrients for plants, supports food chains, and recycles nitrogen through ecosystems.

Nitrogen Cycle Explained - Definition, Stages and Importance

Energy and Energy Conservation

  • Types of Energy: Kinetic, Potential, Thermal, Chemical, Electrical, Nuclear.

  • Law of Conservation of Energy: Energy cannot be created or destroyed, only transferred or transformed.

    • Examples: Solar energy transforming into chemical energy in plants.

  • Renewable vs Non-renewable Energy:

    • Renewable: Solar, wind, hydropower.

    • Non-renewable: Fossil fuels (coal, oil, gas).

Climate Change

  • Causes:

    • Natural: Volcanic eruptions, solar variations.

    • Human: Burning fossil fuels, deforestation, industrial emissions.

  • Effects:

    • Rising global temperatures, melting ice caps, sea-level rise, extreme weather events.

  • Solutions:

    • Reducing emissions, renewable energy use, reforestation, sustainable practices.

Food Chains

  • Definition: A sequence showing how energy and nutrients flow through an ecosystem.

    • Example: Grass → Rabbit → Fox.

  • Trophic Levels:

    • Producers: Plants and algae that make their own food through photosynthesis.

    • Primary Consumers: Herbivores that eat producers.

    • Secondary Consumers: Carnivores that eat herbivores.

    • Tertiary Consumers: Top predators that eat other carnivores.

    • Decomposers: Break down dead material, returning nutrients to the soil.

  • Importance: Shows energy flow, maintains ecosystem balance, and highlights interdependence among organisms.

Galaxies, Stars, Solar System, and Celestial Objects

  • Galaxies:

    • Types: Spiral (e.g., Milky Way), Elliptical, Irregular.

  • Stars:

    • Life Cycle: Nebula → Protostar → Main Sequence → Red Giant/Supergiant → White Dwarf/Neutron Star/Black Hole.

  • Solar System:

    • Components: Sun, 8 planets, moons, asteroids, comets, meteoroids.

  • Celestial Objects: Includes planets, stars, asteroids, comets, and moons.

The Big Bang Theory

  • Definition: Theory that the universe began as a single, dense point around 13.8 billion years ago and has been expanding ever since.

  • Evidence:

    • Cosmic Microwave Background Radiation: Leftover heat from the Big Bang, detected as faint radiation in the universe.

    • Redshift of Galaxies: Light from distant galaxies shifts toward the red end of the spectrum, indicating they are moving away, consistent with an expanding universe.

    • Abundance of Light Elements: Predicted proportions of hydrogen and helium match observations.

  • Importance: Explains the origin of the universe and sets the foundation for understanding cosmic evolution.

Eclipses

  • Solar Eclipse: Moon blocks the Sun (occurs during a New Moon).

  • Lunar Eclipse: Earth blocks sunlight from reaching the Moon (occurs during a Full Moon).

Comparing Planetary Data

  • Key Characteristics:

    • Size, mass, distance from the Sun, composition (rocky or gaseous), number of moons, atmospheric conditions.

    • Example: Earth vs Mars (size, atmosphere, habitability).

Space Technology, Travel, and Hazards

  • Technology:

    • Satellites, telescopes, space probes, rovers.

  • Space Travel:

    • Achievements: Moon landings, Mars rovers, International Space Station.

    • Hazards: Microgravity effects, cosmic radiation, psychological challenges, spacecraft malfunctions.

Media-Based Arguments

  • Evaluating media claims about space and climate change:

    • Check sources, scientific evidence, and bias.

    • Example: Separating fact from misinformation in climate change debates or space exploration feasibility.

Earth-Sun-Moon System

  • Earth’s Rotation and Revolution:

    • Causes day/night and seasons.

  • Moon’s Orbit:

    • Takes ~27.3 days to orbit Earth.

The Moon and Lunar Phases

  • Phases:

    • New Moon, Crescent, First Quarter, Gibbous, Full Moon, Last Quarter.

    • Caused by the Moon’s position relative to Earth and Sun.

  • Tides:

    • Spring Tides: During Full and New Moons.

    • Neap Tides: During Quarter Moons.

mnemonics

Here are some mnemonics to help you remember key concepts in Earth and Space Science:

The Water Cycle

EPCR (Every Penguin Can Run)

  • Evaporation

  • Precipitation

  • Condensation

  • Runoff

The Carbon Cycle

PRO DOC (like a professional doctor)

  • Photosynthesis

  • Respiration

  • Ocean uptake

  • Decomposition

  • Organic matter

  • Combustion

The Nitrogen Cycle

FANAD (Fans of nitrogen!)

  • Fixation

  • Ammonification

  • Nitrification

  • Assimilation

  • Denitrification

Phases of the Moon

New Cows First Get Full Last, Then Wane

  • New Moon

  • Crescent

  • First Quarter

  • Gibbous

  • Full Moon

  • Last Quarter

  • Waning Moon

Order of the Planets in the Solar System

My Very Educated Mother Just Served Us Nachos

  • Mercury

  • Venus

  • Earth

  • Mars

  • Jupiter

  • Saturn

  • Uranus

  • Neptune

Life Cycle of a Star

Never Play Monopoly With Rich Winners

  • Nebula

  • Protostar

  • Main Sequence

  • Red Giant

  • White Dwarf (or Neutron Star/Black Hole)

Eclipses

Solar Starts with Sun, Lunar with Light

  • Solar Eclipse: Moon blocks the Sun.

  • Lunar Eclipse: Earth blocks the light to the Moon.

Let me know if you'd like more or if there are specific topics you need help with