A big hole has opened up in the sun’s outer layer, and it’s sending a strong breeze of solar wind our way. NASA’s Solar Dynamics Observatory took a picture of this gap, which is almost 800,000 km long.
It’s known as a coronal hole, and right now, it’s turning away from Earth. But a few days ago, when it was on the sun’s equator, it was pointing directly at us, sending a stream of particles in our direction.
Think of a coronal hole as a gap in the sun’s outer layer where magnetic fields have opened up, allowing solar wind to escape.
The hole looks dark because the usually glowing hot gas is no longer there—it’s headed our way.
Image credit NASA/SDO