An astronaut aboard the International Space Station has captured a spectacular image of an aurora draped over the Earth far below the orbiting laboratory.
NASA astronaut Scott Kelly (@StationCDRKelly) shared the photograph, taken on Aug. 15, on social media.
In addition to being a beautiful sight to gaze upon, auroras fascinate scientists involved in studying our sun and the energy and particles it puts out. They are among the most stunning effects of energetic particles and magnetic fields streaming from the sun in what is known as the solar wind.
— Scott Kelly (@StationCDRKelly) August 15, 2015
They can also be ejected in giant eruptions known as coronal mass ejections, or CMEs. After traveling from the sun for two or three days, the particles and fields interact with particles trapped near the Earth, which can trigger reactions in oxygen and nitrogen molecules high in our planet's atmosphere that result in the release of light photons. The results, strongest above the Earth's poles, are known as the Aurora Borealis and Aurora Australis — the Northern and Southern lights.
While images have been photographed from space by astronauts before, Kelly's image is particularly striking for including the Earth, the glowing aurora, stars and the exterior of the ISS, all captured in the image released Aug. 18 as NASA's Image of the Day. Kelly, a veteran of three previous missions to the ISS, is currently on a yearlong mission that began in March, to learn the effects of long-term living in space.
Day 141. The chapter of a day ends as it began. #Aurora on a sunrise. Good night from @space_station! #YearInSpace https://t.co/hZBMs9q0CS — Scott Kelly (@StationCDRKelly) August 15, 2015