Flying Through a Geomagnetic Storm


Glowing green and red, shimmering hypnotically across the night sky, the aurora borealis is a wonder to behold. Longtime sky watchers say it is the greatest show on Earth.

It might be the greatest show in Earth orbit, too. High above our planet, astronauts onboard the International Space Station (ISS) have been enjoying an up-close view of auroras outside their windows as the ISS flys through geomagnetic storms.

"We can actually fly into the auroras," says eye-witness Don Pettit, a Flight Engineer for ISS Expedition 30. "It's like being shrunk down and put inside of a neon sign."

Auroras are caused by solar activity. Gusts of solar wind and coronal mass ejections strike Earth's magnetic field, rattling our planet's protective shell of magnetism. This causes charged particles to rain down over the poles, lighting up the atmosphere where they hit. The physics is akin to what happens in the picture tube of a color TV.

Incoming particles are guided by Earth's magnetic field to a pair of doughnut-shaped regions called "auroral ovals." There's one around the North Pole and one around the South. Sometimes, when solar activity is high, the ovals expand, and the space station orbits right through them.

No comments:

Post a Comment