Astronomers in Hat Creek, Calif., are planning today to switch on the first elements of a giant new array of radio telescopes that they say will greatly extend the investigation of natural and unnatural phenomena in the universe.
When the Allen Telescope Array, as it is known, is complete, it will consist of 350 antennas, each 20 feet in diameter. Using the separate antennas as if they were one giant dish, radio astronomers will be able to map vast swaths of the sky cheaply and efficiently.
The array will help search for new phenomena like black holes eating each other and so-called dark galaxies without stars, as well as extend the search for extraterrestrial radio signals a thousandfold, to include a million nearby stars over the next two decades.
A million stars is a lot. To cover them in only twenty years is incredible. But plans for a bigger radio telescope are already underway:
The full array, astronomers say, will be useful not just for science, but also as practice for a truly giant telescope known as the Square Kilometer Array, which would have a combined receiving area of a square kilometer and which astronomers hope to build in Australia or South Africa in 10 or 20 years.
In the past astronomers have aimed to build bigger and bigger telescopes. Eventually they realized that an array of telescopes-both of the radio and the light variety-can be built more cheaply and more powerfully than gigantic telescopes ever could be. Thus, plans to build the array in South Africa, as well as plans to build giant or multiple-array telescopes in Earth orbit, free of the limitations of gravity and interference from the Earth's atmosphere.
In the past there's been some controversy over how much money should be spent searching for life in the galaxy, or whether such a search should even be conducted at all. And it's true that any plans to go to other systems to search for life-with people or even with robots-are as yet untenable, prohibitively expensive or impossible. But the cost to build powerful radio, optical and infrared telescopes on Earth and in space is minute in comparison with even only the other activities we carry out in space, and the potential upside is enormous.