New Eyes on the Cosmos: The Next Constellation of Telescopes Will Dramatically Extend and Sharpen Scientists' View of the Universe
Raloff, Janet, Science News
When Galileo began pointing spyglasses toward the heavens--scanning methodically, classifying what he observed--he started a trend. Four centuries later, telescopes from the huge to the massive peer at the skies with an array of technologies. They look up from all over the Earth--and from far above it. But the heavens still conceal many secrets. So over the next decade or so, Galileo's successors plan to deploy new, super-high-definition spyglasses to view the most distant objects in the cosmos, map the Milky Way and catalog newfound solar systems. Others would survey the heavens for breaking news: stellar explosions, passing comets or the appearance of potential "killer" asteroids.
These new instruments will be far more sophisticated--and colossal--than Galileo's original. And they'll carry astronomical price tags.
Some ground-based telescopes will run $1 billion or more to build, with yearly outlays of $30 million or more throughout the decades they operate. "The scale of these facilities is such now that no single institution can finance them by themselves--not even a single country can," notes Wendy Freedman, director of the Carnegie Observatories in Pasadena, Calif. At least 10 new telescopes or networks of instruments are now in production or in the late stages of design. Until construction is well under way, of course, most astronomers would acknowledge that their pet instruments may encounter delays, or get shelved.
One astronomer who is among the most confident that his instrument is a go: Markus Kissler-Patig, project scientist in Garching, Germany, for the European Extremely Large Telescope. This ground-based colossus, currently slated to begin operation in 2018, will have a primary mirror 42 meters wide (almost half as long as a U.S. football field) and made from nearly 1,000 hexagonal segments, each about 1.5 meters in diameter. Roughly 100 million euros has already been spent on the E-ELT's design, Kissler-Patig says, and all but about a third of its projected construction cost of 1 billion euros is banked or already committed by partnering agencies.
Every 10 years, the U.S. National Academies gathers leading astronomers to assess priorities for new facilities. Results of the current survey are due out in 2010. Waiting to learn how much the astronomy community prizes their proposals has created more than a little rivalry among Pasadena astronomers. Those at the Carnegie Observatories are among scientists planning the 24.5-meter Giant Magellan Telescope, or GMT. Caltech is a lead partner in the international consortium developing the Thirty Meter Telescope, or TMT.
Design on the Giant Magellan Telescope is moving right along, but Carnegie astronomer Alan Dressler notes that "until two or three years ago, I would have bet against seeing two of these big telescopes"--or against U.S.-led consortia building both. "But lately I've begun to believe that GMT has at least a fifty-fifty chance."
Hoping to boost the chances for their instrument of choice, astronomers are pointing to the new science that this coming generation of behemoth spyglasses would kick-start.
View from the ground
In orbit since 1990, the Hubble Space Telescope was the first optical telescope to operate in space. Once its flawed mirror was corrected with prescription optics in 1993, the orbiting observatory began sending back to Earth images of breathtaking clarity. But even with the approaching retirement of Hubble--and with its successor, the James Webb Space Telescope, not designed to send back photos in near-true color--astronomers aren't panicking. Several telescopes now on the drawing board should deliver images with a resolution Hubble engineers could only dream of.
The E-ELT, for instance, will see individual objects with unprecedented detail, delivering images that are at least 15 times crisper than Hubble's--and of much fainter objects. …