The Great Barrier Reef comprises over 2,900 individual reefs and 900 islands off Australia's Queensland coast.
It covers approximately 133,000 square miles across the Coral Sea and is the world’s largest single structure made by living organisms.
More than 1,500 fish species live on the reef, including the clownfish, red bass, red-throat emperor, and several species of snapper and coral trout.
The biodiversity makes the reef a popular tourist destination, especially for scuba divers.
The image to the right was captured by NASA’s Terra satellite just before 11 a.m. local time on Monday, August 13, 2012.
The tropical region seldom produces a cloud-free day such as is seen in the image.
And indeed, there were numerous cumulus clouds over the Coral Sea just east of the reef in the original satellite image.
They were airbrushed out by an Earthweek graphic artist to provide better contrast between the water and coral.
Image: NASA Terra Satellite