Diamond hunting in space

A diamond field as seen from the space shuttle

Scientists and mining engineers are studying images taken from space to pinpoint the best place to dig for diamonds. Our science correspondent David Whitehouse reports:

An ancient plateau

The image of Africa above was taken using an advanced radar system which has been flown several times on the space shuttle. It shows a portion of the Richtersveld national park and the Orange river. The Orange river marks the border between South Africa and Namibia.

The area is famous for diamonds which millions of years ago were washed downstream from the Kimberley diamond area when the Orange river was much larger.

Today, diamonds are found in the ancient silt deposited by the Orange river. The diamond bearing silt is itself buried beneath thick layers of sand and gravel.

The radar-imaging system beams microwaves from a large antenna on the space shuttle and records the echoes from which images can be constructed.

The radar system is pointed Earthwards

The radar can penetrate vegetation and some ground surface layers so the hope is that the data will enable scientists to pinpoint the best areas to look for diamonds.

This image was one of many taken when the space shuttle Endeavour took the Space Imaging Radar system into orbit. It also investigated deforestation in the Amazon, the creeping growth of the Sahara desert and the problems of soils drying out in North America.

Another remarkable image was of an eroded plateau in central Thailand.

The radar echoes can be processed to produce a 3-D effect showing surface detail.