By Sid Perkins
The serendipitous observations of two Earth-orbiting satellites, one passing high over the North Pole while the other whizzed over Antarctica, have revealed that Earth’s auroras aren’t symmetrical.
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Auroras, commonly called the northern and southern lights, are caused by charged particles from space slamming into gas molecules in the upper atmosphere. These ghostly, flickering phenomena are most commonly seen at high latitudes because the charged particles follow the lines of Earth’s magnetic field, which pierces the atmosphere in polar regions.