Infrared View
When a rattlesnake searches for prey, it relies not just on its eyes, but on two "pit" organs below the eyes. These organs detect infrared energy -- the heat of a passing rodent or other potential quarry.
Astronomers rely on infrared to snag some of their quarry, too, including infant stars and the raw materials for planets.
A star like the Sun is a vigorous adult, producing visible light and other forms of energy. In its infancy, though, a star glows like a warm ember, producing infrared but little visible light.
Infrared energy provides important information on how stars and galaxies are born. It also tells astronomers if the raw materials for planets circle newborn stars, and reveals the failed stars known as brown dwarfs. In our own solar system, astronomers use infrared to study the atmospheres of the planets and the surfaces of comets and asteroids.
But water vapor in Earth's atmosphere absorbs most of the infrared energy from astronomical objects. So the only way to see the infrared is to place telescopes far above most of the atmosphere. And infrared detectors must be cooled to hundreds of degrees below zero so their own heat doesn't fog the view.
The highest-flying infrared telescope is the Spitzer Space Telescope, which trails Earth in its orbit around the Sun. The big telescope is far outside Earth's atmosphere, allowing it to strike at important quarry -- with a clear view of the infrared sky.
Script by Damond Benningfield, Copyright 2006
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
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