Lights in the night sky seen from the ISS
Lights in the night sky seen from the ISS
Sky glow visible on Earth's horizon, as seen by astronauts on board the International Space Station (ISS). The green hue is caused by the 557.7 nanometre transition of atomic oxygen, as shown by the energy spectrum in the inset (not to scale). The spectrum indicated by the white curve (width – 170 megahertz) is the baseline emission of atomic oxygen at 4.7 terahertz.
