Sign In Request Beta Access
← Back to Physics

GCSE Physics 10 — Space Physics

Public

Topics include Structure of the Universe & The Solar System, Gravity & Gravitational Field Strength, Orbital Mechanics: Forces & Motion, Orbital Mechanics: Mathematics & Energy, Stellar Formation & The Main Sequence, Stellar Death: Low Mass Stars, Stellar Death: High Mass Stars, and Stellar Classification & HR Diagrams.

Physics EN
150 cards
Study this deck on Deckloop

Preview Cards

A sample of cards from this deck.

Example explainer

A sample of the AI explainer you can generate for cards in this deck.

Structure of the Universe & The Solar System

The hierarchical scale of the cosmos, from our local Solar System to the vastness of the Universe, including the specific bodies that orbit our Sun.

Key points

  • Hierarchy: Planet → Star System → Galaxy (billions of stars) → Universe (billions of galaxies).
  • Our Solar System: Consists of the Sun (a star), eight planets, dwarf planets (e.g., Pluto), moons, asteroids, and comets.
  • Order of Planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. (Mnemonic: My Very Easy Method Just Speeds Up Naming).
  • Formation: The Solar System formed from a nebula (cloud of gas and dust) about 4.6 billion years ago. Gravity pulled mass to the center (Sun), and the remaining disc accreted into planets.
  • Light Year: A unit of distance (not time), equal to the distance light travels in one year (≈ 9.5×10159.5 \times 10^{15} m).

Worked example

Question

Explain the difference between a planet and a moon, and describe the difference between an asteroid and a comet.

Solution

1. Planet vs Moon: A planet orbits a star (the Sun), whereas a moon is a natural satellite that orbits a planet.
2. Asteroid vs Comet: An asteroid is a rocky/metallic object found mainly in the Asteroid Belt (between Mars and Jupiter) with a roughly circular orbit. A comet is made of ice and dust, usually has a highly elliptical orbit, and develops a tail when near the Sun due to melting ice.

Common pitfalls

  • Thinking a light year is a measure of time (it is distance).
  • Confusing the rotation of Earth (day) with its orbit (year).
  • Believing the Sun is at the exact center of a planet's orbit (it is at one focus of an ellipse, though often approximated as the center).
  • Thinking the Universe and Galaxy are the same thing.

Prerequisites

  • Basic gravity (attraction between masses)
  • Definitions of star vs planet
Further resources