Astronomy GCSE : Week 11
2016–17 course delivered by Think Physics and the Centre for Life
This week we’re looking at the interactions between the Sun, Moon and Earth.
Although you’re probably familiar with the phases of the moon, eclipses and why they occur, it’s worth making sure that you have got this clear in your mind. A lot of people make mistakes.
Always remember that the diagrams you see in books/online are not to scale, and that can lead to some misunderstandings about celestial movements.
Web links for Week 11
Veritasium has a number of films relevant to this week’s topic:
Other useful links for this week:
- An explanation of sidereal time
- Some information about the mean and apparent Sun.
- One reason why knowing the Sunrise and sunset times used to be very important was that it was one of the main ways of navigating. This webpage has information about how to navigate using the Sun.
Specification statements for week 11
- demonstrate an understanding that the Moon and Sun appear to be the same size when viewed from Earth
- recall the period of the lunar phase cycle (29.5 days)
- demonstrate an understanding of lunar phases and deduce the lunar phase cycle from given data
- use diagrams to explain why the lunar phase cycle is (2.2 days) longer than the orbit period of the Moon
- describe the appearance of partial and total solar and lunar eclipses f describe, using diagrams, the mechanisms causing solar and lunar eclipses
- demonstrate an understanding that the duration of total solar and lunar eclipses are different and that they do not occur every new and full Moon
- describe the terms ‘solar day’ and ‘sidereal day’
- explain why a solar day is longer than a sidereal day.
- demonstrate an understanding of the terms ‘apparent Sun’ and ‘mean Sun’
- demonstrate an understanding of the term ‘equation of time’ (apparent solar time — mean solar time) and perform simple calculations
