The International Space Station (ISS) orbits at approximately 350km above the earth, travelling at an average speed of 27,724 kilometres per hour. Completion of each orbit is in about 90 minutes, which means that, in a 24-hour day, the space station orbits approximately 16 times. It was during one of such orbits that Christina Koch of NASA captured a time-lapse photo.
The time-lapse, created from a total of 400 individual photographs, was taken in 11 minutes as the ISS travelled from Namibia toward the Red Sea.
According to NASA, the image includes many natural and artificial lights. On the ground, stationary features like cities appear as pale yellow-white dotted streaks; with each dot marking another frame captured. Many of the thinner dotted lines with darker orange hues are fires burning across Angola and the Democratic Republic of the Congo.
The circular streaks in the upper left corner of the image are star-trails, and toward the north, thunderstorms covering much of central Africa. White flashes of lightening were also captured, outlining Earth’s limb.
The faint greenish-yellow tracing of the upper atmosphere, seen above the horizon, is known as airglow. Airglow stretches 80 to 645 kilometres into the Earth’s atmosphere.
The International Space Station (ISS) is a habitable artificial satellite in low Earth orbit. The ISS is a joint project between five participating space agencies: CSA (Canada), ESA (Europe), JAXA (Japan), NASA (United States), and Roscosmos (Russia). The ownership and use of the space station are established by intergovernmental treaties and agreements.
The ISS serves as a microgravity and space environment research laboratory in which crew members conduct experiments in biology, human biology, physics, astronomy, meteorology, and other fields. The station is suited for the testing of spacecraft systems and equipment required for missions to the Moon and Mars. The ISS maintains an orbit with an average altitude of 400 kilometres (250 mi) employing re-boost manoeuvres using the engines of the Zvezda module. It circles the Earth in roughly 92 minutes and completes 15.5 orbits per day.