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Galaxies and the universe

CONCEPTUAL
Science›Space Systems & Earth's History|Ages 12—13|ID: mt_v9uYnIY5-B

Describe the scale of the universe, including the structure of galaxies, the position of the Sun in the Milky Way, and the use of light years as a unit of distance, and appreciate why space exploration requires enormous timescales

Mastery Evidence

  • Defines a light year as the distance light travels in one year
  • Describes the structure of a galaxy and states that the Sun is a star in the Milky Way galaxy
  • Compares the distances within the solar system with the distances between stars and between galaxies, expressing them in appropriate units

Assessment Prompt

“If [child] heard that a star is 400 light years away, could they explain what a light year means, roughly how far that is, and why we will never be able to visit it with current spacecraft?”

Curriculum Standards2 alignments

MS-ESS1-2Next Generation Science Standards (NGSS) Middle Schoolcodes only
Standard code — full text not included in this dataset.
KS3.Sci.Phys.SpacePhysics.5The national curriculum in England
Astronomical Distances and Star Life Cycles

the light year as a unit of astronomical distance; using light years to describe distances to stars and galaxies; the life cycle of a star (qualitative)

Science · KS3

Prerequisites3

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  • Earth & Space Vocabulary soft

    Describing the scale of the universe using light years and galaxies draws on this vocabulary

  • Universal Gravitation soft

    Gravity as a universal force provides context for why galaxies hold together and for the orbital dynamics at galactic scale

    • The solar system (age 11+) hard

      Explaining orbital motion as gravity-driven centripetal force requires knowing what is in orbit (planets, moons) from the solar system topic

      • The solar system hard

        Detailed solar system structure (moons, asteroids, comets, orbital periods) extends KS2 overview of planets orbiting the Sun

        • Naming the Planets hard

          Describing sun, Earth, and moon as spherical bodies and planets orbiting the sun requires solar system vocabulary

        • Sun, Moon, and stars hard

          Must observe sun/moon patterns before learning about the solar system model

          • Naming the Planets hard

            Describing predictable patterns of sun, moon, and stars requires planet, star, moon, orbit vocabulary

          • Why seasons change hard

            Must observe sun/moon/star patterns before relating daylight to time of year

            • Naming the Planets soft

              Relating daylight length to time of year draws on orbit and solar system vocabulary

            • Seasonal changes soft

              Seasonal changes observation supports daylight pattern recognition

      • Naming the Planets hard

        Describing the detailed solar system structure including moons, asteroids, and comets requires all this vocabulary

    • Mass vs Weight hard

      Universal gravity and orbital mechanics build directly on mass vs weight and the concept that gravitational field strength varies between planets

      • Gravity & Falling Objects hard

        KS3 weight = mass × g extends KS2 introduction to gravity as the force pulling objects toward Earth

        • Balanced & Unbalanced Forces soft

          Balanced/unbalanced forces supports understanding gravity as an unbalanced force on unsupported objects

          • Pushes & Pulls hard

            Must understand pushes/pulls before investigating balanced vs unbalanced forces

            • Drawing Force Diagrams soft

              Understanding pushes and pulls as forces is supported by the arrow representation of magnitude and direction

          • Drawing Force Diagrams hard

            Investigating balanced and unbalanced forces requires drawing force diagrams to record and analyse experimental findings

          • Friction & Surfaces hard

            Must understand friction affects motion before investigating balanced/unbalanced forces

            • Pushes & Pulls hard

              Must understand forces change motion before comparing movement on different surfaces

              • Drawing Force Diagrams soft

                Understanding pushes and pulls as forces is supported by the arrow representation of magnitude and direction

            • Forces Vocabulary hard

              Comparing how things move on different surfaces requires friction vocabulary

        • Forces Vocabulary hard

          Explaining gravity requires the force vocabulary: gravity, weight, non-contact force

        • Drawing Force Diagrams hard

          Explaining gravity as a downward force requires representing it as a downward arrow in a force diagram

        • Contact & Non-Contact Forces hard

          Must know about non-contact forces before learning gravity as a non-contact force

          • Forces Vocabulary hard

            Distinguishing contact from non-contact forces requires these exact terms

          • Drawing Force Diagrams soft

            Distinguishing contact and non-contact forces is clarified by drawing force diagrams showing where arrows originate

          • Friction & Surfaces hard

            Must experience contact forces like friction before distinguishing contact vs non-contact forces

            • Pushes & Pulls hard

              Must understand forces change motion before comparing movement on different surfaces

              • Drawing Force Diagrams soft

                Understanding pushes and pulls as forces is supported by the arrow representation of magnitude and direction

            • Forces Vocabulary hard

              Comparing how things move on different surfaces requires friction vocabulary

  • Star Brightness & Distance hard

    Understanding the wider universe (galaxies, light years) extends the KS2 concept that the Sun is a nearby star and brightness varies with distance

    • The solar system hard

      Must know the sun is a star and planets orbit it before arguing about star brightness and distance

      • Naming the Planets hard

        Describing sun, Earth, and moon as spherical bodies and planets orbiting the sun requires solar system vocabulary

      • Sun, Moon, and stars hard

        Must observe sun/moon patterns before learning about the solar system model

        • Naming the Planets hard

          Describing predictable patterns of sun, moon, and stars requires planet, star, moon, orbit vocabulary

        • Why seasons change hard

          Must observe sun/moon/star patterns before relating daylight to time of year

          • Naming the Planets soft

            Relating daylight length to time of year draws on orbit and solar system vocabulary

          • Seasonal changes soft

            Seasonal changes observation supports daylight pattern recognition

    • Why the Sun Looks Brightest soft

      Enrichment knowledge of star brightness vs distance supports formal argument about apparent brightness

      • The Sun is a star hard

        Must know the Sun is a star before understanding why it appears brighter than other stars

        • Sun, Moon & Stars hard

          Must know the Sun is a sky object before learning it is a star

          • Why seasons change soft

            Curriculum daylight/seasons observation supports exploratory Sun/Moon/stars identification

            • Naming the Planets soft

              Relating daylight length to time of year draws on orbit and solar system vocabulary

            • Seasonal changes soft

              Seasonal changes observation supports daylight pattern recognition

        • Our Solar System hard

          Must know about the solar system before learning the Sun is at its centre

          • Sun, Moon & Stars hard

            Must know the Sun and stars before learning about planets and the solar system

            • Why seasons change soft

              Curriculum daylight/seasons observation supports exploratory Sun/Moon/stars identification

              • Naming the Planets soft

                Relating daylight length to time of year draws on orbit and solar system vocabulary

              • Seasonal changes soft

                Seasonal changes observation supports daylight pattern recognition

Unlocks2