Day and night captured in a single photo by International Space Station astronaut flying over Earth’s ‘shadow line’
NASA engineer Christina H Koch took the remarkably detailed picture

THE transition from day to night has been captured in a single stunning shot by an astronaut on board the International Space Station.
NASA engineer Christina H Koch took the remarkably detailed picture as the ISS passed over the Earth’s “shadow line”.
“A couple times a year, the @Space_Station orbit happens to align over the day/night shadow line on Earth,” she tweeted.
“We are continuously in sunlight, never passing into Earth’s shadow from the Sun, and the Earth below us is always in dawn or dusk. Beautiful time to cloud watch. #nofilter.”
She is currently a part of the Expedition 59 and 60 crew that launched to the International Space Station in March 2019.
ISS astronauts are used to incredible views of the Earth's sunrises and sunsets and they can see as many as 15 or 16 every day.
This is because the space station travels at 17,200 miles per hour as it orbits 220 miles above the Earth – meaning it completes one trip around our planet every 92 minutes
Koch shared her snap almost exactly two months after an image showed the Earth in perfect balance between night and day on the first official day of spring.
The snap of the planet's terminator - the line separating night and day - was taken from space on the spring equinox, which fell on March 20 this year.
With half of the planet illuminated in light and the other steeped in darkness, the picture captures the Earth’s beautiful symmetry.
MOST READ IN SCIENCE
During the equinox, the amount of daylight and darkness is nearly equal at all latitudes.
It occurs twice a year, in March and in September and heralds the changing seasons.
In the Northern Hemisphere, the spring equinox also marks the beginning of autumn in the Southern Hemisphere.