Paper 1: Key Skills

Learn how to use latitude and longitude to locate positions on Earth using the Equator and Prime Meridian as key reference lines.

Learn how to recognise key asterisms and use pointer stars to locate important stars, constellations and deep-sky objects.

Learn how to read and plot Right Ascension and Declination to locate objects on the celestial sphere.

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Learn how to use altitude and azimuth to describe the position of an object in the sky from a particular location.

Learn how to use Right Ascension, Local Sidereal Time and Hour Angle to determine the position and timing of celestial objects.

Learn how to link a star’s Hour Angle to its approximate azimuth and position relative to the observer’s meridian.

Learn how to use Polaris and the celestial poles to determine latitude, altitude, declination and polar distance.

Learn how to determine whether a star is circumpolar and calculate its altitude at upper and lower transit.

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Learn how to use rising, setting and culmination times to determine the best time to observe an object and compare locations.

Learn how to use the rate of precession to calculate changes in the orientation of Earth’s axis over long periods of time.

Learn how shadow measurements and angular differences can be used to calculate the circumference of the Earth.

Learn how timings from a lunar eclipse can be used to estimate the diameter of the Moon relative to the Earth.

Learn how ratios and apparent sizes can be used to estimate the distances to the Moon and the Sun.

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Learn how to use Kepler’s Third Law to calculate orbital periods, orbital radii and compare the masses of astronomical objects.

Learn how the inverse-square relationship can be used to compare gravitational forces at different distances.

Learn how to convert between kilometres, Astronomical Units and other measures of astronomical distance.

Learn how planetary positions such as conjunction and opposition can be used to calculate distances between planets and the Earth.

Learn how to use the Equation of Time to convert between apparent solar time and mean solar time.

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Learn how to use an analemma to determine the Sun’s declination and the Equation of Time throughout the year.

Learn how to use time-zone information, longitude and local mean time to compare times at locations around the world.

Learn how local noon, Greenwich Mean Time and the Equation of Time can be used to calculate longitude.

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