February 4, 2008

The Telescope Arms Race is Under Way

The development of new technological advances is setting the course for a worldwide telescopic arms race. Astronomers are currently planning to construct large land-based telescopes with the capability of seeing further back in time than ever before.

The telescopes will produce clearer images than even those taken by the Hubble Space Telescope which was put into orbit in 1990 and was long respected for its ability to clear up distortion caused by the Earth's atmosphere. Now, new land-based telescopes can fix these problems too.

The building boom is expected to take place over the course of the next decade and cost billions of dollars to achieve the unprecedented clarity and magnification. Some scientists compare the process to switching from regular TV to high-definition.

The proposed names of the observatories show how competitive the race has become: the Giant Magellan Telescope, the Thirty Meter Telescope and the European Extremely Large Telescope, which was downsized from the OverWhelmingly Large Telescope. Add to those NASA's James Webb Space Telescope, a super eye in the sky, scheduled for launch in 2013.

It is the hope of astronomers that they will be able to get an unprecedented look at the first planets outside of our solar system as well as be able to catch a glimpse of what was happening near the birth of the universe.

When scientists view a planet from a large distance, they are actually able to view it as it was millions and millions of years ago, because it takes so long for light from the object to reach Earth. But the new telescopes will be so powerful that they should be able to gaze back to a couple of hundred million years after the Big Bang, which scientists believe happened 13.7 billion years ago.

"We know almost nothing about the universe in its early stages," said Carnegie Observatories director Wendy Freedman, who chairs the board that is building the Giant Magellan Telescope. "The GMT is going to see in action the first stars, the first galaxies, the first supernovae, the first black holes to form."

According to The Associated Press, the telescope arms race is being made possible by the development of two new technologies: one reliant on modern lasers and computing power and the other inspired by ancient Greek and Roman tilework.

The first technology, adaptive optics, will allow land-based telescopes to display a clear view of space, free from distortion caused by the Earth's atmosphere.

Adaptive optics relies on a laser to create an artificial star, or a constellation of fake stars, in the sky. Astronomers then examine the fake stars and use computers to calculate how much atmospheric distortion there is at any given time. Then they adjust the mirrors to compensate like a pair of eyeglasses. This adjustment happens automatically hundreds of times per second.

The second technological advancement makes bigger mirrors possible. Scientists are now able to piece smaller mirror segments together rather than using one large mirror.

In astronomy, the bigger the mirror, the greater the possible amount of light that can be grabbed from the universe.

Jerry Nelson, scientist at the twin-telescope Keck Observatory in Hawaii, pioneered this technique and told The Associated Press he got the idea from looking at how the Greeks and Romans tiled their baths. This technique is going from 36 segments in current telescopes to 492 segments with his new project. Nelson is currently working on the Thirty Meter Telescope.

For the past decade and a half, the Keck has had the largest Earth-bound telescopes, with mirrors nearly 33 feet in diameter.

However, three giant land observatories, proposed for construction within the decade, are going to dwarf those:

  • - The Giant Magellan Telescope. A partnership of six U.S. universities, an Australian college, the Smithsonian Astrophysical Observatory and the Carnegie Institution of Washington will place the telescope in Las Campanas, Chile, around 2016. The plan is for an 80-foot mirror. The cost is around $500 million.
  • - The Thirty Meter Telescope. The California Institute of Technology, the University of California and the Association of Canadian Universities for Research in Astronomy are aiming for a telescope with about a 98-foot mirror by 2018. No site has been chosen. The cost is about $780 million.
  • - The European Extremely Large Telescope. A partnership of European countries called the European Southern Observatory already has telescopes in Chile and is aiming for a new one with a mirror of 138 feet, scaled back from initial plans of 328 feet. The Europeans are aiming for a 2018 completion, but have not chosen a specific location yet. The cost would be $1.17 billion.

ESO's European Extremely Large Telescope would be largest of the proposed telescopes and would have the ability to see 20 to 100 times more sharply than current land-based telescopes.

Associated Press reports that project managers are fairly confident that they will receive the necessary funding to achieve their goals. However, some astronomers worry that there may not be enough private or government money for all of them, so they find themselves competing for funding, even as they cheer each other on.

"Oh, you ain't seen nothing yet," said 2006 Nobel Prize-winning physicist John Mather, senior project scientist for NASA's James Webb Space Telescope.

The $4.5 billion Webb Telescope is designed to travel 900,000 miles beyond Earth's orbit and will not be limited by the atmospheric distortion. It will use its own version of adaptive optics. Webb's mirror, which is 2 1/2 times bigger than Hubble's, has 18 segments.

Both the Thirty Meter and European telescope are looking at several sites in Chile, but the Thirty Meter team is also considering Baja Mexico and Hawaii. What's needed is the right combination of atmospheric conditions, weather, high altitude, prevailing winds and dark skies.

Smaller, more specialized telescopes are already in various stages of design and construction.

One project in Hawaii would be created with hopes of keeping an eye out for dangerous asteroids. And in Chile, dozens of high-precision antennas are being erected for a huge radio astronomy observatory, called ALMA that would look into the universe in a different way.

Still, it is those large land-based telescopes which will provide the furthest and clearest pictures of the universe. The pictures to come, Nelson said of the Thirty Meter project, will "knock your socks off, faint stuff that Hubble can't see."


Photo Caption: Chad Sanders, a computerized numerical control (CNC) machinist for AXSYS Technologies in Cullman, Ala., monitors machining operations on a mirror segment for NASA's James Webb Space Telescope. AXSYS, a subcontractor for Ball Aerospace of Boulder, Colo., delivered the last of 18 mirror segments, called "blanks," in January. They will next undergo grinding and polishing operations at Tinsley Laboratories in Richmond, Calif. The James Webb Space Telescope, NASA's next Great Observatory, is scheduled to launch to orbit in 2013 to study the oldest stars and galaxies formed in the universe. The program is managed by NASA's Goddard Space Flight Center in Greenbelt, MD. (Image Credit: NASA)


On the Net:

Thirty Meter

Giant Magellan Telescope

European Extremely Large Telescope

James Webb Space Telescope