Half the World Away

An aurora (pl. aurorae or auroras) is a natural light display in Earth's upper atmosphere caused by charged particles from the Sun colliding with atoms in the atmosphere. These collisions excite oxygen and nitrogen, which then emit light of different colours such as green, red, and purple. When observed in high-latitude regions they are called polar lights and aurora polaris. In the Arctic they are called the northern lights or aurora borealis; in the Antarctic, the term southern lights or auror...