NASA is 'calling all selfies' to create an Earth Day image of the planet

The US space agency invites people across the globe to take a picture of themselves on Tuesday, Earth Day 2014, and post it for NASA to use in a ‘#GlobalSelfie.’ Move over, 'blue marble.'

NASA may make the saying "we belong to the earth" true in a kind of digital-literal way on Earth Day 2014. The space agency is inviting people around the world to send in selfies, and it will assemble the cellphone snapshots of human faces into a composite image of Earth.

It’s one small click for whole lot of men and women, one giant piece of computerized collage for NASA.

America’s space agency has long been known for helping mankind study and appreciate Earth as well as the wonders of space and the solar system.

Back in December 1968, a couple of years before the first national Earth Day celebration, US astronauts orbited the moon and took a photo of Earth as it appeared over the gray lunar horizon. The image of a distant “earthrise” brought home to humanity, perhaps as never before, the notion of living together on one precious and relatively small planet.

And in a scientific sense, NASA-launched satellites are helping to track everything from polar ice to global rainfall and fires in the Amazon rain forest.

“Selfie” photos have been making their own history lately, in a less cosmic way. The arms-length self-portraits are a common currency of Facebook pages and Twitter feeds, becoming the stuff of headlines on occasions when they go viral online or turn heads because of the celebrities involved. (When Ellen DeGeneres posed with movie stars on Oscar night, it was a publicity coup for mobile-phone maker (and Oscars sponsor) Samsung.)

How do you participate in the Earth Day photo event? Here’s what the space agency says:

“While NASA satellites constantly look at Earth from space, on Earth Day we're asking you to step outside and take a picture of yourself wherever you are on Earth” as part of a worldwide celebration of Earth Day. You post the photo to a social media website such as Twitter, and type #GlobalSelfie as a hashtag to bring the photo to NASA’s attention.

“Post your photo to Twitter, Instagram or Google+ using the hashtag #GlobalSelfie, or post it to the #GlobalSelfie event page on Facebook or the #GlobalSelfie group on Flickr. You can also join the #GlobalSelfie Google+ event page,” the agency explains. “Tell us where you are in a sign, words written in the sand, spelled out with rocks.”

For people unaccustomed to spelling with rocks, NASA has created a ready-to-print page (you can pick from 22 languages) on which to write your location. 

NASA says its mosaic image won't be put together on Earth Day, but will be released in May along with a video using the images.

The event is social, but just like at the Oscars these selfies may also serve a promotional purpose. NASA is publicizing its efforts to study mankind’s home planet as well as ones far away. The agency says it has “17 Earth-observing missions orbiting our home planet right now – and several more launching this year – [to study] Earth's atmosphere, land and oceans in all their complexity.”