An astronaut took this photograph of the Aurora Australis in August 2017. At the time, the International Space Station was moving over the southern Indian Ocean towards the Great Australian Bight and Melbourne, Australia. Click here to see a video of the flight over the aurora.
Auroras are created in the upper atmosphere when the solar wind (a stream of charged particles emitted by the Sun) interacts with the Earth’s protective magnetic field. Charged particles within the magnetosphere are accelerated down field lines toward the ionosphere, where they collide with different gases (particularly oxygen and nitrogen) and emit light as a reaction. Auroras often appear as neon green, purple, yellow, or red, depending on the gas molecules being excited. Green, for example, indicates collisions with oxygen.
References & Resources
Astronaut photograph ISS052-E-63378 was acquired on August 19, 2017, with a Nikon D4 digital camera using a 22 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 52 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Andi Hollier, Texas State University, Hx5, JETS Contract at NASA-JSC.
