US astronaut Don Pettit has captured a striking image of a red aurora from the International Space Station (ISS).
According to Pettit, auroras of this size and intensity appear only two to three times during a six-month mission aboard the ISS.
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Auroras occur when charged particles from the sun collide with atoms and molecules in Earth’s upper atmosphere, releasing energy in the form of light.
While green auroras are more common, red auroras are rare and linked to intense solar activity. The colour is rare because of the high altitude needed for it to occur.
Scientists say the phenomenon occurs when particles interact with oxygen at altitudes above 150 miles (241 km), where the atmosphere is thinner.
