The giant Gemini North telescope in Hawaii is one of many powerful new scopes. This picture was taken slowly over a 20-minute period. Because the earth is turning, stars appear as streaks in the night sky.
| The giant Gemini North telescope in Hawaii is one of many powerful new scopes. This picture was taken slowly over a 20-minute period. Because the earth is turning, stars appear as streaks in the night sky. |
When did the universe begin? Does it stretch on forever? Are there other solar systems out there like our own? Is there a faraway planet just like ours, where creatures ask the same questions?
Humans have puzzled over such mysteries since they first gazed up at the night sky. If answers can be found, they may come from high on the mountaintop of Mauna Kea in Hawaii or a handful of places like it. Mauna Kea is dotted with silvery domes, sprouting like huge mushrooms from the rocky soil. The domes hold some of the world’s most powerful telescopes.
A telescope’s power depends largely on the size of the light-gathering mirror inside it. A huge, perfect mirror captures even the faintest, most faraway star glow.
Eight years ago California’s Hale telescope, with its 17-foot (5-meter) mirror, was the biggest and best. But on Mauna Kea alone, four telescopes now see farther than the Hale. The Gemini North, with a mirror more than 26 feet (8 meters) across, released its first scientific images last month. It offered a glimpse of the mysterious center of our Milky Way galaxy. Japan’s Subaru telescope, about the same size, started up last year. But the kings of the mountain are the twin Keck telescopes, with light-gathering surfaces 33 feet (10 meters) across!
The Keck 1, which opened its eye on the sky in 1993, was the first of a new generation of scopes helping scientists see farther into space. Others sit on peaks in South Africa, Chile, Spain’s Canary Islands, Arizona and Texas. These spots have tall mountains that are far from bright city lights—ideal places to see the stars. Already the new scopes are changing our view of the universe. "What’s been happening in the telescope game is incredible," says Harvard University astronomer John Huchra.
|  Before the Gemini's giant mirror was installed in 1998, an engineer inspected its shiny coating to make sure it was flawless. |
It’s All Done With Mirrors
The big new telescopes reflect brilliant ideas about how to build telescope mirrors. Until now, the best telescopes had mirrors like thick glass hockey pucks. They were tough to make, wildly expensive and so heavy it was hard to build a structure strong enough to hold them.
In the 1980s, scientists invented ways to make bigger but lighter mirrors. California astronomer Jerry Nelson designed the Keck’s mirror not from a single slab of glass but from 36 smaller sheets that, under a computer’s control, move as one. In Europe, design teams made a thin, floppy mirror, a bit like one of those shiny Mylar party balloons. Computers control a movable support system that adjusts the mirror’s shape.
New technology can eliminate the flicker of stars caused by Earth’s ever shifting atmosphere. By taking out the twinkle, the new scopes can match the sharpness of pictures taken by the Hubble Space Telescope, a 7-foot telescope that orbits high above Earth.
The giant telescopes are making heroic discoveries. Take the work of planet hunter Geoff Marcy and his team. "We’ve discovered 35 planets orbiting sunlike stars so far," says the California astronomer. "The vast majority of them have been found with the Keck."
A European team has used four new Very Large Telescopes (VLTS) in Chile to solve an astronomic riddle: if the universe has existed for 8 billion to 12 billion years (as Hubble research shows), why do some stars appear to be 14 billion years old? The team’s answer: the Hubble data was wrong! vlt research shows the universe is about 14 billion years old and the oldest stars are 12 billion.
|  As the sun sets on Hawaii's Mauna Kea mountain, the Gemini North telescope is ready for an evening of stargazing. |
On Beyond Big
Already scientists are dreaming up their next playthings. The names show what they have in mind. CELT (California Extremely Large Telescope), OWL (Overwhelmingly Large Telescope) and others would boast mirrors up to 330 feet. That’s bigger than a football field! No one could have predicted the discoveries being made with today’s new telescopes. With bigger ones, says astronomer George Djorgovski, "we’ll almost certainly find things we never could have imagined."