It's widely believed that one of the most spectacular sights you can see on this Earth is the Aurora Borealis or Aurora Australis. Judging from the photos and videos astronauts send home from aboard the International Space Station, it's pretty spectacular from space, too. To give you a taste of just how amazing it is, NASA has released video on its ultra high-definition channel comprising time-lapses of both auroras shot by video equipment on ISS.
Usually seen towards the polar regions of Earth, auroras are caused by the solar wind, and can be observed more frequently during the more active period of the sun's 11-year cycle, the solar maximum. The glorious lightshow occurs when charged electrons and protons are disturbed by the solar winds and collide with neutral particles, causing ionisation, which makes the sky glow.