astronaut photography

Posted by Ellen

The desert of northern Saudi Arabia is among the most barren places on earth. But beginning in 1986, when water wells were drilled into deep aquifers, vast stretches of desert land have been irrigated for agricultural use. So much of Saudi Arabia is now farmland that the fields are visible from space, as shown here in this photo taken last week by astronauts on the International Space Station. The circular fields are each about one kilometer in diameter.

This is energy-intensive agriculture; it takes a lot of fossil fuel to pump water from so deep underground and to operate the center-pivot irrigation systems that keep the wheat fields and vegetable patches green despite bone-dry desert air. But Saudi Arabia has a lot of fossil fuel, and its desert agriculture is expanding rapidly.

(The water in the aquifers is itself fossilized, left over from the Ice Age, before this part of the world became so hot and arid.)

Posted by Ellen

A couple of weeks ago, when the International Space Center was looping around the southern part of the globe, heading toward Antarctica from Australia, astronauts used the little digital camera on board to snap this picture.

The fires were intentionally set by farmers clearing fields or pastures to make way for spring growth. The green horizon is the Aurora Australis, bright pulses of electromagnetic energy released when solar pulses are deflected toward the earth's southern magnetic pole. Green is the most common color of auroras, produced when solar energy disrupts the normal spinning of oxygen molecules in the upper atmosphere; auroras can also be red, pink, or orange, depending on the atmospheric gases involved.

The space station itself is visible across the top of this photo and in the lower right corner.