Breathtaking photos taken by NASA astronaut show boundary between day and night on Earth

Each day at sunrise, dark blues and blacks fade into powder blue, with hints of bright orange lighting up the sky. Early risers can spot the "terminator" or "twilight zone"—the line separating day from night. From space, though, the view is remarkably different. In June 2020, NASA astronaut Bob Behnken (@astrobehnken), aboard the International Space Station (ISS), tweeted two breathtaking images of the terminator line, captivating thousands of people.

Orbiting 248 miles (400 kilometers) above Earth, the ISS experiences 16 sunrises and sunsets daily. In the photos Bob shared, a sliver of Earth’s sphere is visible. One side remains in shadow while the other is bathed in sunlight, with the edge of the lit portion glowing brightly. “My favorite views of our planet that capture the boundary between night and day,” Bob described in the caption. The pictures were topped up with snippets of solar panels and apparatus of the space station.

According to the Daily Express, these photographs were taken only a couple of days after Bob and a fellow astronaut Chris Cassidy participated in a historic spacewalk on the ISS. This team of astronauts became the first to splash down in an American spacecraft in 45 years, thus completing the Demo-2 mission, a collaboration between NASA and Elon Musk’s SpaceX. Bob, along with another astronaut Douglas Hurley lifted off from NASA Kennedy Space Center’s Launch Complex 39A towards ISS on May 30, 2020, on board the SpaceX space capsule "Crew Dragon Endeavour."

Per the Daily Express, their objective for this mission was to replace aging nickel-hydrogen batteries for one of the orbiting laboratory’s two power channels, as well as conduct two spacewalks. This mission followed the previous mission by NASA astronauts Christina Koch and Jessica Meir, who made history by conducting the first-ever all-women spacewalk in October 2019.

When Bob shared the breathtaking photographs, hundreds of people commented. “So incredibly beautiful. Life’s problems whatever they may be, don’t seem too big from that vantage point,” said @sactotrixie. @arlingtonstarla commented, “I love what looks like a blue Horizon line just before the blackness of space.” @ccdarko7empest quipped, "I don't mind being in space until 2020 is over!"

Among these people, some even triggered flat-earthers to see these photos and change their views about the planet. For instance, @iammrsumitd commented, “This is also for everyone who thinks the earth is flat.” @shanuirshad joked, "Flat earthers have left the chat!"

Just a week before Bob shared these stunning “terminator zone” photographs, the other astronaut on the mission, Hurley had shared another picturesque view of a huge Sahara dust plume spreading over the Atlantic Ocean. Plus, after the spacewalk, Bob also shared another photograph depicting the view of the sunset from the ISS.