photo #9391668

From the International Space Station, astronauts get to look down on auroras. Here, orbiting 273 miles (439 kilometres) over the Indian Ocean south of Perth, Australia, they glimpsed an aurora that most never see from the ground: the aurora australis, or southern lights.Auroras form as energy from the solar wind stretches the Earth’s magnetic field far out into space on its night side like a gigantic, invisible elastic band. When the distorted field reconnects, some of its stored energy accelerates the charged particles towards Earth and into the upper atmosphere. The collisions that result excite atoms and molecules in the upper atmosphere, which then emit light as they release the excess energy. The green and red here come mainly from atoms of oxygen excited to different energy states.The southern lights tend to receive less attention than their northern counterparts, the aurora borealis. This is just because so much of the auroral zone in the Southern Hemisphere lies over the open ocean. There are simply far fewer people in the right place to see them directly overhead. But the International Space Station sees all. From up there, an aurora even in the middle of nowhere need never be overlooked.Image Credit: NASA/Jessica Meir