Mochi IsleWhy is the sun behind you when you see a rainbow?
In short: A rainbow forms when sunlight shines through countless raindrops floating in the air and is split into its colours. The light bends and bounces inside the drops, which is why the sun is always behind you and the rain in front.
How it works
Sunlight looks white, but it is really a mix of many colours: red, orange, yellow, green, blue, indigo and violet. When light passes from air into a water drop, it bends. Each colour bends by a slightly different amount, violet the most and red the least, so the white light fans out into a band of colours.
Inside the drop, the light bounces off the back and comes out of the front, bending again so the colours spread further apart. That is why the sun must shine from behind you onto raindrops in front of you, so the coloured light reflects back into your eyes. Rainbows are easiest to see in the morning or late afternoon, when the sun is low.
The colours of a rainbow really blend smoothly into each other, but we usually name seven. Sometimes a fainter second rainbow appears outside the first one. Its colours are in the opposite order, because the light has bounced twice inside each drop before reaching you.
Where to see it in New Zealand
New Zealand's weather often swings between showers and sunshine, so rainbows are common, especially in the morning or late afternoon when the sun is low. In Māori tradition, the rainbow is often linked with the atua (god) Uenuku.
Try it together
On a sunny morning or late afternoon, stand with your back to the sun and ask an adult to spray a fine mist from a hose or spray bottle in front of you. Look for a small rainbow in the mist. Never look straight at the sun.
Kids also ask
Can you reach the end of a rainbow?
No. A rainbow is not an object in one place; it depends on where the sun, the raindrops and your eyes are. When you move, the rainbow moves with you, so everyone sees their own rainbow.
When is the best time of day to see a rainbow?
Early morning or late afternoon, when the sun is low. Stand with the sun behind you and rain or spray in front. Around midday the sun is often too high, so the rainbow sits below the horizon.
In the game, “Rainbow” is a nature card from the Sky set, and it can turn up on any island.
Your child finds this card by reaching the right place or meeting the right weather on the island, and lights it up by answering the question on the back. Tap the button below and the game shows your child which island it is on and how to find it. Mochi Isle is a browser learning game for ages 5 to 18; the main island and the daily lesson are free.
Find “Rainbow” on the island ↗ All cards in the Sky set