Look up on a hazy day and you might catch something magical: a soft ring of color glowing around the Sun. That is exactly what caught Eon's eye in this clip. "The sunlight actually hits the Earth's atmosphere and makes a rainbow color," he explains — and a friend agrees: "It's like a halo around the Sun!"
Let's unpack the two big ideas Eon is exploring here: the Sun and the atmosphere.
The Sun is a star
The Sun looks special because it is so close and so bright, but it is really a star — just like the tiny twinkling points you see at night. It is simply the nearest star to Earth, which is why it looks huge and warm instead of like a faraway dot. All of its light has to travel a long way through space before it ever reaches us.
The atmosphere is our blanket of air
When that sunlight finally arrives, the first thing it touches is the atmosphere — the layer of air wrapped all the way around our planet. The atmosphere is the air we breathe, and it also acts like a protective blanket. Eon noticed something clever in the clip too, pointing out a gap in the clouds: "Here's a little hole in the atmosphere," he says, where the Sun peeks through.
Why a rainbow halo appears
Here is the part Eon got exactly right. As sunlight passes through the air (and tiny droplets or ice in it), the light gets bent — scientists call this refraction. "The atmosphere refracts the light," Eon's friend says. White sunlight is secretly made of many colors mixed together, so when it bends, those colors can spread out into a glowing ring or halo. "A bit blue, I think," Eon adds — and he's onto something, because the way air scatters light is also why our sky looks blue.
So the next time the Sun wears a colorful ring, you'll know the story: starlight from our nearest star, bending as it slips through Earth's atmosphere.
Try it
On a sunny day, stand in the shade of a building so the bright Sun is blocked (never look straight at the Sun — it can hurt your eyes). Hold up a glass of water near a window and look for the little rainbow it casts on the floor or wall. The water is bending the light into colors, just like the atmosphere does to make a halo around the Sun. Can you spot every color in your tiny rainbow?