Space Station Soars Over the Southern Lights

It must be ISS flyover video season, because here's another breathtaking beauty made from images taken by the Expedition 28 crew aboard the space station! Here we get to witness the glamor of the Aurora Australis -- a.k.a. the Southern Lights -- as the International Space Station orbits high above.

The Aurora Australis is the southern hemisphere's version of the Aurora Borealis, and is created in the same way: high-energy ions emitted from the sun collide with Earth's magnetic field and excite atoms of various elements located in the upper atmosphere, which then release light energy we can see.

The colors of the aurora are determined by the type of atoms releasing light as well as their altitudes. The most common gas at lower levels of the Earth's ionosphere is oxygen, which emits light in the green and yellow end of the spectrum -- colors our eyes detect particularly well.

Other colors, like reds, blues and purples, are also possible but harder to detect without using longer-exposure photography.

Besides shimmering sheets of aurorae, a high-altitude phenomenon called airglow is also visible as a thin line of pale yellow light surrounding Earth's limb. This is caused by energy released by molecules high in the atmosphere that were charged up during the day by ultraviolet light from the sun... not unlike a glow-in-the-dark sticker!

Between this video and the previous one posted here, it's no wonder that the astronauts lucky enough to work on the Space Station love their jobs as much as they do. In spite of all the inherent risks to working in low-Earth orbit, you simply can't beat the view.

Read more at Discovery News