Earth Day is even celebrated in space.
Canadian astronaut Chris Hadfield sent down some well wishes from the International Space Station today (April 22) in honor of Earth Day.
"Good Morning, World, and Happy Earth Day from orbit!" the current space station commander wrote from his Twitter account (@Cmdr_Hadfield) earlier today. "One touch of nature makes the whole world kin."
Hadfield also spoke to a group of Canadian students and journalists about how life in space has changed his view of the Earth.
"If anything my respect and my concern and my love for the Earth has only been deepened by [having this] new perspective on the planet," Hadfield said.
Hadfield thinks that a "vital" part of his job is to show the world what it is like to live in orbit, he said during the Canadian event.
The first Canadian commander of the station is known for beaming down beautiful pictures of the Earth from the space station's perspective as well as creating videos detailing everything from cooking on the station to cutting his nails in microgravity.
Hadfield also reflected on the significance of the Earth through Twitter later in the day.
"One quick look at our planet reminds me of the importance of Earth Day," Hadfield wrote.
NASA has scheduled its own set of Earth Day activities today. The space agency is releasing photos and hosting social media events in honor of the Earth celebration. These events are the culmination of a month-long campaign by the agency to help engage the public with Earth science from space.
Hadfield and two other residents of the International Space Station — Russian cosmonaut Roman Romanenko and NASA's Tom Marshburn — are scheduled to fly back to Earth in May after a six-month stint on board the orbiting outpost.
The $100 billion space station has been permanently staffed by astronauts from around the world since 2000. The station was built by five different space agencies representing 15 countries with construction beginning in 1998.