Welcome to practical physicsPracticle physics - practical activities designed for use in the classroom with 11 to 19 year olds

Observing the night sky

Class practical

Observations of the stars, planets and the Moon for students to make.

Apparatus and materials

Camera with B (open shutter) setting

Health & Safety and Technical notes

Caution students about where and when (and with whom) they make their observations of the night sky, so that they do not put themselves at risk. If appropriate, inform parents/guardians.

See the guidance note Teaching Aids for information on where to look for the stars and planets.



a Ask students to observe the sky at least twice in one evening, with an interval of about two hours between observations.
b Ask students to watch the Moon and to note its position relative to the stars. Then, one or two hours later, look again and note the new position of the Moon relative to the stars.
c Extend the previous experiment to a month. Note the position of the Moon at the same hour on each possible night for a month. The observations should relate to the stars, and also to the position in the sky relative to the horizon. Ask students to draw the phases of the Moon throughout the monthly cycle.
d Show students the brightest planets - Venus, Jupiter and, possibly, Saturn.


Teaching notes

1 Students will need to be prepared for this observation in anticipation that a clear starry night appears. Normally the best times are during winter when the skies are predicted to be clear and a frost is forecast. Viewing the sky away from the city lights is recommended. These observations will probably have to be done at home for many students.

A compass is helpful so that students know in which direction they are looking.
A record of observations should be made.

2 For a it will help if pictures of a few easy-to-identify constellations are available before the observing time, so that students will recognize them and can direct their observations towards them.
In b the Moon appears to travel across the star pattern. See guidance note Observing the night sky.

For c there will be times when the Moon is invisible during the night and will only be seen during the day. The rising and setting of the Moon can often be found from diaries or the newspapers.

This experiment was safety-checked in April 2007


Related guidance

Teaching aids   

Observing the night sky