In the years since Project Ozma, Seti has evolved from a set of theories into a science that is practised by eminent astronomers throughout the world

Frank Drake, Seti pioneer

The eventual aim is to construct an array of small radio dishes whose total area will add up one hectare, hence the name of the instrument, the One Hectare Telescope, or 1hT.

This means that the seven-dish prototype could eventually be joined by an array of hundreds, perhaps thousands of small backyard-type satellite dishes linked by sophisticated electronics to create an unparalleled observing instrument for the Search for Extra-Terrestrial Intelligence (Seti).

"This prototype launches the next generation of Seti research in a bold way," said Dr Jill Tarter, director of research at the privately funded Seti Institute in California.

"There is also tremendous potential for other radio astronomy. The 1hT is a fundamentally new way to build radio telescopes, and it's not an overstatement to say that the world astronomy community is paying very close attention to this project."

Evaluation prototype

Dr Leo Blitz, director of the University of California-Berkeley's Radio Astronomy Laboratory, said the 1hT draws on the lab's success in designing, building and operating arrays. "The 1hT is a natural for us. It will be a wonderful tool for discovery," he said.

The dishes will do conventional astronomy as well

The instrument unveiled is a prototype and is not intended to conduct serious Seti searches or even more traditional radio astronomy. Instead, it will serve as an evaluation prototype.

With the lessons learned, a second, larger prototype will be built in 2002. The final version of the 1hT will be constructed at UC Berkeley's Hat Creek Observatory, located about 465 kilometres (290 miles) northeast of San Francisco. It should be completed and operational in 2005.

Once finished, it will be the world's largest telescope devoted to Seti and among the largest radio telescopes in the world used for any purpose. It will be comparable in signal "collecting" area to the Very Large Array of radio telescopes in New Mexico.

By adding radio dishes to it those of 1hT, the final array has the potential to become the largest radio telescope in the world.

Gradual start

The 1hT team will start by searching 1,000 nearby Sun-like stars and gradually move outward to encompass 100,000 and then one million candidate stars in our galaxy.

In the Milky Way galaxy alone, there are an estimated 400 billion stars.

"This is an exciting day for Seti," said Frank Drake who conducted Project Ozma, the first ever Seti in 1960. Drake is currently President of the Seti Institute and Research Professor of Astronomy at the University of California-Santa Cruz.

"In the years since Project Ozma, Seti has evolved from a set of theories into a science that is practised by eminent astronomers throughout the world. The 1hT is the next logical step in the advancement of that science."

Construction of the final 1hT is estimated to cost about $25 million, much less than the cost of building a similar sized radio telescope using conventional design and methods.