This year, as participants all over the world switch off their lights Saturday (March 31) for Earth Hour, one of the astronauts living on the International Space Station will be the first to observe the event from onboard the orbiting outpost.
Earth Hour will take place worldwide on Saturday from 8:30 to 9:30 p.m. local time, during which time people are encouraged to turn off their lights for an hour to raise awareness about climate change and to highlight the need for sustainability.
Dutch astronaut André Kuipers will keep watch over the planet from the space station's orbital perch 240 miles (386 kilometers) above the Earth's surface, according to officials at the European Space Agency (ESA).
"There is no better way to raise awareness for the future of the most beautiful planet in the universe," Kuipers said in a statement. "Working to understand our planet is what ESA does every day, and taking part in Earth Hour enables people to join us in this commitment."
Earth Hour began in Sydney, Australia, in 2007, when the World Wildlife Fund (WWF) inspired residents of the city to show their commitment to the planet by switching off their lights for an hour.
"It showed that everyone, from children to CEOs and politicians, has the power to change the world they live in," the event's organizers said in a statement on the Earth Hour website. "In Sydney, Australia, 2.2 million individuals and more than 2,000 businesses turned their lights out for one hour to take a stand against climate change."
Since then, Earth Hour has become one of the world's largest voluntary global events that raises awareness about sustainability and the planet's limited resources. [10 Surprising Results of Global Warming]
In 2011, more than 5,200 cities participated in Earth Hour, including 1.8 billion people in 135 different countries across all seven continents, ESA officials said.
Kuipers, a WWF ambassador, has been using his unique vantage point in orbit to draw attention to issues of sustainability, including how humans can reduce their ecological footprint on the planet.
The Dutch spaceflyer arrived at the International Space Station in December, and throughout his six-month mission at the complex, he plans to film and photograph WWF projects that are currently underway in various locations around the world, including Borneo and the North Pole, ESA officials said.
There are currently six astronauts living on the International Space Station. Kuipers is scheduled to return to Earth on July 1.