On a sunny day, stand with the Sun on your back and look at the ground, the shadow of your head coincides with the antisolar point.
- The anti-solar point is the position on the rainbow axis around which the arcs of a rainbow appear.
- An imaginary straight line can always be drawn that passes through the Sun, the eyes of an observer and the anti-solar point – the geometric centre of a rainbow.
- The idea that a rainbow has a centre corresponds with what an observer sees in real-life.
- As seen in side elevation, the centre-point of a rainbow is called the anti-solar point.
- ‘Anti’, because it is opposite the Sun with respect to the location of an observer.
- Unless seen from the air, the anti-solar point is always below the horizon.
- The centre of a secondary rainbow is always on the same axis as the primary bow and shares the same anti-solar point.
- First, second, fifth and sixth-order bows all share the same anti-solar point.