Happy Earth Day, Earthlings. For Earth Day 2013, take a moment to appreciate your home for what it is -- a blue pinpoint on a vast black canvas.
In a 2009 post on NASA Science, Dauna Colter wrote about the 40-year anniversary of Apollo 11, and her words -- and a historic picture from 1969 -- resonate today.
The photo, taken by astronaut Bill Anders, showed Earth rising over the moon's horizon. The effects of that image were deeply felt.
"For the first time in history, humankind looked at Earth and saw not a jigsaw puzzle of states and countries on an uninspiring flat map," Colter wrote, "but rather a whole planet uninterrupted by boundaries, a fragile sphere of dazzling beauty floating alone in a dangerous void. There was a home worthy of careful stewardship."
Since that photo was taken, many images of Earth from space have followed -- weather turbulence as well as incredible nighttime images showing the twinkle of city lights.
Perhaps among the most recent stirring images was contained in a tweet from Chris Hadfield, commander of the International Space Station.
From his perch in the orbiting ISS, Hadfield tweeted condolences on April 15 following the Boston Marathon bombings.
He followed it with a picture of a "somber" Boston from space.