This spectacular image of the Earth is the most detailed, true-colour picture of the planet ever taken from space.
It was made from many different images collected by Nasa satellites and put together as a composite photograph.
It shows the "blue marble" beauty of our home planet and was produced by a team of scientists using months of satellite observations of the land, oceans, sea ice and clouds, covering every square kilometre of the Earth's surface.
The wafer-thin atmosphere on which all life depends can just be discerned as a brilliant blue glow on the western horizon, while the vast expanse of blue ocean illustrates that the Earth is truly a water world.
The first images of the Earth taken from space -- by the Apollo 8 mission to orbit the Moon -- created a universal sense of awe when they were published in 1969.
They forever changed our view of the planet and helped launch the environmental movement, as they depicted the apparent vulnerability of our only life-support system.
Much of the data on which this latest image is based was collected by Nasa's Moderate Resolution Imaging Spectroradiometer.
It is a remote-sensing instrument flying more than 700km above Earth on the Terra satellite.
A Nasa spokesman said that views showing North America and the Indian Ocean have been downloaded more than a quarter of a million times in the past couple of days.
In another famous image of Earth, taken in 1990 by the Voyager 1 spacecraft at a distance of some 3.7bn miles, the Earth appeared as a "pale blue dot" surrounded by the vastness of space, like a tiny mote of dust caught in a sunbeam.
When the late Carl Sagan, the renowned American astronomer and science writer, first saw this image of the planet he was inspired to write these words: "Look again at that dot. That's here. That's home. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives."