Two giant holes appeared on the sun's surface. They're called coronal holes, and they'll send solar winds toward Earth, revealing northern lights.

This phase will last for about half a billion years. The red giant phase ends when the Sun’s core gets hot enough (about 100 million kelvins) to support the fusion of helium into carbon.

When the Sun runs out of hydrogen fuel and expands into a red giant, it will eventually encompass the innermost planets of the solar system, out to about Earth’s orbit.