Aurora Australis light show
IF SPECTACULAR VIEWS OF Earth aren’t enough, astronauts aboard the International Space Station (ISS) have been treated to a display of nature’s own light show.
The snapshot, above, of the Aurora Australis, was taken on May 24, 2010 from ISS as it overlooked the Southern Indian Ocean at an altitude of 350 km above the Earth.
According to NASA, this extraordinary image was taken during a geomagnetic storm that was most likely caused by a coronal mass ejection – huge spurts of gas threaded with magnetic field lines, ejected from the Sun over the course of several hours.
According to Dr Gary Burns from the Australian Antarctic Division in Hobart, auroras are visible in Australia. “States like Tasmania, towards the polar region, would be the best place to see them, but it can seen as far north as southern Queensland on rare occasions,” he says.
The chances of seeing Aurora Australis is related to the sunspot cycle and they are more common around the months of the equinoxes. The sunspot cycle repeats approximately every 11 years with the next storm due in 2012.
Because the intensity of light in the Aurora Australis is low, it is most likely to be observed late at night, at a time Gary refers to as “magnetic midnight.”
The most commonly sighted colours of an aurora are green and red, which are seen when ions in solar wind collide with oxygen and nitrogen atoms in the upper atmosphere.
