Taking an image of Earth is no easy feat. Since NASA’s Explorer 6 satellite first took a blurry photo of our world back in 1959, methods and techniques to snap that perfect picture of our home have come on leaps and bounds, and the images often become very famous. In fact, 2002’s Blue Marble image was so popular that it eventually ended up as the default background on Apple’s iPhone.
The first Blue Marble image of the entire Earth – coined for apparently portraying our planet as a marble-like object – was taken by Apollo 17 astronauts in 1972 as they made their way back from a mission. The image they took 40 years ago was just a single snapshot, but today image-editing software such as Photoshop is used to enhance the picture, though great pains are gone to not to detract from the reality of the shot.
NASA’s most recent Earth portrait, dubbed ‘Blue Marble 2012’, was taken by an Earth observation satellite called Suomi NPP. For the satellite to shoot this image technicians on the ground had to take a picture of Earth six times as the satellite passed over one point, allowing them to combine several layers into one image.
The image was taken in January 2012 and compiled by NASA scientist Norman Kuring. The satellite flies in a polar orbit at a height of 824 kilometres (512 miles). However, the perspective of the image is from an altitude of 12,743 kilometres (7,918 miles) at a point ten degrees south latitude and 45 degrees east longitude, owing to the nature of the composite image.