Subatomic particles fly out from the sun constantly, in what we call the solar wind. Luckily for living beings, the Earth's magnetosphere deflects most of these particles away from us.
But at the planet's far polar regions, some of these particles enter our atmosphere and provide the sweeping light shows we know as auroras.
Auroras emit light in colors across the visible spectrum, but just a few dominate, with green being the most common color. Ionizing oxygen high in the Alaska skies allowed for these rare red aurora rays.