Solar System

Planetary Order and Solar System Architecture

  • Sequential Order of the Planets:

    • Mercury

    • Venus

    • Earth

    • Mars

    • Jupiter

    • Saturn

    • Uranus

    • Neptune

  • Mnemonic Device:

    • "My very easy method just speeds up naming" (used to recall the correct order from Mercury through Neptune).

  • Structural Zones of the Solar System:

    • Inner Planets: The first 33 planets, classified as terrestrial bodies composed of rock.

    • Asteroid Belt: Located directly after the inner terrestrial planets.

    • Outer Planets: The next 44 planets, classified as gas planets.

    • Kuiper Belt: Located beyond the outer gas planets.

Astronomical Models of the Universe

  • Geocentric Model:

    • The belief and cosmological model stating that Earth is the centre of the universe.

  • Heliocentric Model:

    • The belief and astronomical model stating that Earth orbits the Sun.

Earth's Axial Tilt and Seasonal Variations

  • Earth's Axial Rotation:

    • Earth is continuously rotating on a 23.5∘23.5^\circ axis.

  • Mechanisms of Seasons:

    • Seasons are caused by Earth's tilt.

    • Hemispheric exposure:

      • More sunlight on a hemisphere results in warmer weather and a longer day.

      • The opposite hemisphere receives less sunlight, resulting in winter and an opposing season.

  • Equinoxes:

    • Periods characterized by equal day and equal night.

    • Occur during autumn and spring.

  • Solstices:

    • Summer Solstice: The longest day in summer.

    • Winter Solstice: The shortest day in winter.

Lunar Phases and Terminology

  • Sequential Progression of Moon Phases:

    • New Moon

    • Waxing Crescent

    • First Quarter

    • Waxing Gibbous

    • Full Moon

    • Waning Gibbous

    • Third Quarter

    • Waning Crescent

  • Definitions of Lunar Terminology:

    • Waxing: Getting bigger.

    • Waning: Getting smaller.

    • Crescent: Less than half of the Moon is lit.

    • Gibbous: More than half of the Moon is lit.

Solar and Lunar Eclipses

  • Solar Eclipses:

    • Occur when the Moon blocks the Sun's light from reaching Earth.

    • There are 44 types of solar eclipses:

      • Total

      • Partial

      • Annular

      • Hybrid

  • Lunar Eclipses:

    • Occur when the Earth blocks the light of the Sun from reaching the Moon.

    • There are 33 types of lunar eclipses:

      • Total

      • Partial

      • Penumbral

Oceanic Tides

  • Definition of Tides:

    • The periodic rise and fall of sea levels.

  • Spring Tides:

    • Frequency: Occur 22 times every lunar month.

    • Tidal Range: Feature higher high tides and lower low tides.

    • Lunar Alignment: Only happen during a full moon or a new moon.

  • Neap Tides:

    • Frequency: Happen every 22 lunar months.

    • Tidal Range: Feature higher low tides and lower high tides.

    • Lunar Alignment: Only happen during 1st1\text{st} quarter moons and 3rd3\text{rd} quarter moons.