Nasa unveiled its "global selfie" on Thursday, a mosaic of more than 36,000 pictures uploaded to social media showing people and places around the world in commemoration of Earth Day, the US space agency said.

Nasa asked people on April 22, Earth Day, to upload pictures tagged with #GlobalSelfie to social media sites like Facebook, Twitter and Instagram.

Users on every continent and 113 countries or regions - including Antarctica, Yemen and Peru - joined in. After weeks of collecting and curating the more than 50,000 submissions, the so-called "global selfie" was released.

"We were overwhelmed to see people participate from so many countries. We're very grateful that people took the time to celebrate our home planet together, and we look forward to everyone doing their part to be good stewards of our precious Earth," said Peg Luce, deputy director of Nasa's Earth Science Division.

The 3.2-gigapixel zoomable mosaic shows the tens of thousands of selected pictures arranged to look like Earth as it appeared to the Suomi National Polar-orbiting Partnership climate satellite orbiting the planet on Earth Day. (https://www.nasa.gov/content/goddard/2014-globalselfie-wrap-up/#.U36H_Ch7Tms)

Nasa has 17 Earth-observing satellites in orbit, and five more missions to gather data on the planet are slated to launch this year, Nasa said. The agency said it will be the first time in more than a decade that so many Nasa earth science missions have been launched in a single year. -Reuters