Earth Day selfie out of this world

Nasa's Earth mosaic contains more than 36,000 individual photos. Photo / Nasa

The competition for "ultimate selfie" is heating up in the name of climate change.

Nasa has compiled more than 36,000 of the photographs to make its Global Selfie with Earth Day, a worldwide awareness campaign against climate change and environmental issues.

More than 50,000 people from around the world submitted their selfies that were narrowed down and assembled over several weeks into a mosaic of the earth.

The accurate depiction of the earth, as seen from space, was created after people tagged #GlobalSelfie on their photos uploaded to social media on Earth Day, April 22.

The dual images are based on views of each hemisphere captured on the same day by satellite as part of a project that collects data on long-term climate change and short-term weather conditions.

Other selfies have taken social media by storm.

Ellen DeGeneres' photo of fellow celebrities at the Academy Awards broke records for the most shared Twitter post.

Pope Francis' papal selfie was also a viral hit, along with Nasa astronaut Rich Mastracchio's snap aboard the International Space Station with the reflection of earth in his helmet, and some koalas at an Australian Zoo that operated remote controlled cameras. Some Kiwis managed to take royal selfies with the Duke and Duchess of Cambridge in the background during their recent tour of the country.