Last updated at 07:31

Nasa releases pictures of Earth's beauty

Nasa marked Earth Day by releasing some of its best images of our planet taken from space - by its satellites, its research aircraft and astronauts aboard the International Space Station (ISS) - in the past year. Here is a selection of them:

Flying over the Gulf of Aden and Horn of AfricaNASA
Flying over the Gulf of Aden and Horn of Africa, European Space Agency (ESA) astronaut Samantha Cristoforetti took this photo from the International Space Station (ISS)
Yellowstone national parkNASA
An image of Yellowstone National Park in the United States was posted by Nasa astronaut Reid Wiseman as he prepared for his return journey to Earth
Solar Eclipse shadows over clouds in the Arctic OceanNASA
Shadows from the solar eclipse are reflected on clouds over the Arctic Ocean in images captured by Nasa's Terra satellite on 20 March 2015
View from ISS of Great Lakes and Central USNASA
The Great Lakes and central United States at night - taken from the ISS by flight engineer Barry Wilmore on 7 December 2014
AuroraNASA
Flying through an Aurora - European Space Agency astronaut Alexander Gerst posted this on 29 August 2014
Windswept valleys in Northern AfricaNASA
Windswept valleys in Northern Africa - another photo taken by Alexander Gerst, this time on 6 July 2014
Melt Ponds in GreenlandNASA
Warmer weather melts snow and ice on Greenland's glaciers which collect in depressions on the surface to produce these sapphire-coloured ponds
Great Sandy Desert, AustraliaNASA
Active dune movements in the Great Sandy Desert in north-western Australia
Iberian PeninsulaNASA
Night time in Spain and Portugal - the entire Iberian Peninsula captured on 26 July 2014