Finding your way in the sky

Two pieces of information are enough to say where something is in the sky: its direction along the horizon (north, east, south, west) and its altitude, how high it is above the horizon, from 0° (on the horizon) to 90° (the zenith, straight overhead).

Finding the cardinal points

• The Sun rises roughly in the east and sets roughly in the west; exactly so only at the equinoxes.
• In the northern hemisphere the Sun is towards the south at midday.
• At night, in the northern hemisphere, Polaris marks north to within one degree.
• A phone compass works, but keep it away from metal objects.

Measuring the sky with your hand

With your arm fully stretched, your hand becomes a protractor: the ratio between arm and hand is similar for almost everyone.

• Your little finger covers about 1° (twice the width of the full Moon).
• Three fingers together cover about 5°.
• A closed fist covers about 10°.
• An open hand, thumb to little finger, covers about 20–25°.

When GAIA says "low in the east, 10° above the horizon", it means one fist above the horizon towards the east.