Learning objective

Understand that the Sun is the nearest star to Earth and that astronomical distances are measured in light-years, defined as the distance light travels in one year in a vacuum.

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Cambridge IGCSE Combined ScienceSpace physicsCore content

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Understand that the Sun is the nearest star to Earth and that astronomical distances are measured in light-years, defined as the distance light travels in one year in a vacuum

This point belongs to Stars and the Universe, especially Stars and the Universe outcomes.
You need to be able to understand that the Sun is the nearest star to Earth and that astronomical distances are measured in light-years, defined as the distance light travels in one year in a vacuum.
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DefineState

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Paper 3 structured question: Stars and the Universe

Paper 3Theory (Core)2 marks

Description

Astronomical Distances

Astronomers often use light-years to measure distances in space. A light-year is defined as the distance light travels in one year in a vacuum, which is about 9.46 trillion kilometers.

a
Define What is a light-year?
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[2]

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Calculate the duration it takes for light to cover significant distances, such as between celestial bodies in the Solar System.
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Recognize that the Sun holds the majority of the Solar System's mass, which accounts for the planets' orbits around it.
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Define orbital speed using the formula 2 r π v = T, where r represents the orbit's radius and T is the orbital period, and be able to recall and apply this equation.
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Understand that the gravitational pull of the Sun is the force that keeps objects in orbit around it.
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Know that the Sun is a medium-sized star primarily composed of hydrogen and helium, emitting most of its energy in the infrared, visible, and ultraviolet parts of the electromagnetic spectrum.
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