Eighteen months ago, astronomer Frank Drake was pondering the cheapest way to build a huge radio telescope when he remembered the small TV satellite dish in his back yard.
The 10-foot-wide antenna behind his Santa Cruz, Calif., home provided good television reception for the past decade without needing any fancy parts, unlike the telescopes he uses to scan the sky for signs of alien civilizations.Astronomers worldwide have been looking for a cheaper way to build radio telescopes, but up to this point they've been held back by the cost of the technology.
When Drake looked at his white TV dish, he wondered whether hundreds of the backyard-metal mushrooms were erected side by side -- one in front of the other, so many that they covered a few football fields -- could duplicate the power and sensitivity of some of the world's largest radio telescopes.
"I think people had brought it up before but thought it was so obvious that it was a bad idea," he said.
But now the University of California at Berkeley and the SETI Institute in Mountain View, Calif., are taking Drake's idea seriously and moving to build his dream telescope, officials announced Monday.
They're going to be partners in constructing a one-of-a-kind radio telescope made up of as many as 1,000 satellite dishes similar to the ones in people's yards.
The university and institute plan to build the One-Hectare Telescope (1hT) at the Hat Creek Observatory in the northern Sierra Nevada near Lassen Volcanic National Park. It will have a total listening area of almost 2.5 acres. By comparison, the world's largest radio telescope, Mt. Arecibo in Puerto Rico, has a collecting area of 18 acres.
UC Berkeley has operated the Hat Creek Observatory since the early 1960s and runs an array of 10 dish antennae used solely for radio astronomy.
Not only will the 1hT advance Berkeley's astronomical research, but it will also search for signals that could be emanating from hundreds of billions of miles from Earth. The new telescope will be the world's largest devoted to the search.
"It's going to make everybody stand up and take notice of what we're doing," said Drake, who in 1960 pioneered the use of radio telescopes to search for extraterrestrial intelligence (SETI).
The SETI Institute is the world's leading research organization dedicated to using radio telescopes to capture signals that may be coming from civilizations elsewhere in the universe. Drake is president of the institute's board of directors and a research astronomer and astrophysicist at the University of California at Santa Cruz.
Unlike any other telescope in the world, the 1hT will be made up of 500 to 1,000 backyard dishes -- the actual number to be determined by the size of dish that's selected. The antennae will be wired together so they operate like one telescope.
Until a couple years ago, it wasn't cost effective to interconnect large numbers of antennae. Today, faster computers are commercially available and antenna receivers are cheaper and more sensitive.
"When I first heard of the idea, I thought it was completely nuts," said Leo Blitz, director of the UC Berkeley Radio Astronomy Lab. "I thought, 'How are you going to find a computer to analyze all of these signals coming in?' But I thought about it more and realized that these commercial dishes are so very, very good at operating at the frequencies we need."
The 1hT will cost considerably less to build than a conventional telescope, because most of the parts are mass-produced, emphasized UC Berkeley astronomer William "Jack" Welch who's also vice president of the SETI Institute's board of directors.
"We want to build something that has more capability than some of the biggest telescopes in the world, but we want to do it at a fraction of the cost," he said.
"If we were to build the 1hT in conventional ways, it would cost upward of $100 million. But by using these already-commercially-available dishes, we can do it for as little as $10 million or $15 million."
The SETI Institute will fund the 1hT's construction and the university plans to provide the site and staff to get it up and running.
Work on the prototype should start this year at Hat Creek and it will probably take three to six years to build the full array, the officials said.
The universe is full of gases and chemicals emanating radio waves at the speed of light, but as graceful as ripples on a pond. Radio telescopes, which are basically large antennae used to capture the signals, have an advantage over optical telescopes because they "see" through clouds of gases and cosmic dust.
They can turn radio waves into pictures just as cameras use light to make photographs, and give astronomers awesome views of whirling black holes, galaxies tearing into one another and the primordial ingredient of the universe -- hydrogen gas.
Astronomers will use the 1hT about half the time to observe objects from the interior of the solar system all the way to the edge of the universe, Blitz said.
"One of the main things we'll be able to do is make maps of atomic hydrogen gas, the raw material out of which galaxies and stars are formed," he said.
The 1hT will offer a far different benefit to researchers who spend their lives sifting through the heavens in hopes of finding radio signals from distant civilizations. The antenna array will expand the exploration for extraterrestrial life like no other project has ever done, Drake said. "It will increase the search tenfold," he said.
The SETI Institute was founded in 1984 and was funded by NASA to develop a program to systematically search for alien radio waves, which could be in the form of deliberate messages beamed at Earth or leakage from alien communication devices similar to our televisions, radios, radar and cell phones.
About $60 million was spent on SETI until Congress pulled the plug in 1993 because of spending cutbacks, as well as questions over the program's legitimacy.
The SETI Institute kept the program alive thanks to financial supporters like computer pioneers William Hewlett and the late David Packard (Hewlett-Packard Co.), Intel Corp. co-founder Gordon Moore and Microsoft co-founder Paul Allen.
Project Phoenix was launched in 1995 and is the world's most comprehensive search for alien intelligence. Its mission: To explore 1,000 nearby stars and listen for extraterrestrial signals. So far, 417 stars have been searched.
Radio astronomers worldwide will be watching 1hT closely because its innovative design is a prototype for an international project to construct a massive telescope with a diameter of more than a half-mile. A telescope that size would be the largest in the world and cost billions of dollars if it had a conventional design.
Scientists from at least 10 countries are looking for cheaper ways to make the mega telescope without compromising its size and its sensitivity.
Similar to the 1hT, an array of 100,000 backyard satellite dishes could be the solution scientists are looking for, Blitz said.
"If things go as we would like them to go, there would eventually be one that's 100 times bigger," he said. "That's really the whole other side of this project."