South Pole Telescope

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Under the cold, dry skies of the south pole, astronomers are searching for clues to one of the greatest scientific mysteries of our time: the mystery of dark energy.

Astronomers discovered dark energy a decade ago. They found that the universe is expanding faster today than it was just a few billion years ago. The gravity of all the galaxies and dark matter in the universe should cause the universe to expand more slowly as it ages, but that's not the case -- something is causing it to expand faster.

Scientists called this "something" dark energy, but they don't really know what it is. It might be a sort of "anti-gravity" that pushes galaxies away from each other. Or it might just mean that our understanding of gravity is incomplete.

One of the first steps toward discovering the nature of dark energy is the South Pole Telescope. It's beginning its work this year. It observes a form of energy that's invisible to the eye -- sub-millimeter waves. The south pole is a good spot for studying this form of energy because its skies are extremely clear and dry -- there's no water vapor to absorb the waves.

The telescope is looking for giant clusters of galaxies. The way that galaxies clump together is related to the way the universe expands, which is influenced by dark energy. So measuring clusters of galaxies at different times should help scientists begin to solve the mystery of dark energy.

More about dark energy tomorrow.

Script by Damond Benningfield, Copyright 2008

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