FOR KIDS: How the outer sun gets so hot
The solar corona is a superhot envelope that surrounds the sun, just as Earth’s atmosphere surrounds our planet. The only way to see the corona from Earth is during a solar eclipse — and even then, observers have to wear sunglasses or risk permanent eye damage. The corona is also a source of mystery: Scientists have known for decades that this layer can be millions of degrees hotter than more inner layers of the sun.
If that doesn’t seem unusual, consider this: If the same thing were true of a campfire, you’d be more likely to burn your finger if you held it far away than up close. And if you wanted to roast a marshmallow, you’d be able to do so far from the flames.
Scientists know a lot about the sun. It’s the nearest star, it shines all the time and it provides the energy needed for life on Earth. But what’s heating the corona? Scientists have been scratching their heads and brainstorming ideas about why the outer layer is so blazing hot, especially when there are cooler layers below. Some have long wondered if magnetic waves help to heat the corona.
In a new study of solar observations, scientists indeed discovered waves in the corona that could add oomph to the heating process.