NASAさんのインスタグラム写真 - (NASAInstagram)「Red and green auroras dance above Earth⁣ ⁣ This spectacular view of the "northern lights" over Canada was captured on Sept. 15, 2017, by the crew aboard the International Space Station (@ISS). The station was near the highest point of its orbital path, and its main solar arrays are seen in the left foreground.⁣ ⁣ Auroras are one of the many Earthly phenomena the crew on the space station can observe from their perch high above the planet. Auroras also capture the imagination of scientists who study incoming energy and particles from our Sun. They are one effect of such energetic particles, which can speed out from the Sun both in a steady stream called the solar wind or from giant eruptions known as coronal mass ejections or CMEs. After a trip toward Earth that can last three days, the solar particles and magnetic fields cause the release of particles already trapped near Earth, which in turn trigger reactions in the upper atmosphere in which oxygen and nitrogen molecules release photons of light. The result: the Northern and Southern lights. ⁣ ⁣ Credit: NASA⁣ ⁣ #Aurora #NASA #SpaceStation #NorthernLights」12月26日 4時20分