Blown away by the Very Large Array

On the Plains of San Agustin, 27 huge dish antennas make up the world's largest radio telescope. Photos: Astronomy central

DATIL, N.M.--I'm standing in the middle of "the center of the known universe," as this room is sometimes called. And in a way, it feels like that's actually where I am.

That's because I'm in the control center of the Very Large Array, a collection of 27 dish antennas, each of which weighs 230 tons and has a diameter of 25 meters. Together, the antennas form the world's largest radio telescope.

The VLA, as it's known, is a true sight to behold. It is located at 6,970 feet in the Plains of San Agustin, about 50 miles west of Socorro, N.M., and I've come here as part of Road Trip 2007, my journey around the Southwest in search of some of the most interesting science- and technology-related destinations. This definitely counts.

This is awesome country, with gorgeous brown and tan mountains, a huge sky and, it turns out, some of the most advanced and prodigious scientific equipment the world has ever known.

You try looking at more than two dozen giant dish antenna spread over a giant plain on a beautiful day and not be impressed. Almost impossible.

Together, the 27 antennas combine to create the resolution of a single antenna 22 miles across, with the sensitivity of a dish 130 meters in diameter, according to the VLA's Web site. What that means is that "you can make images of almost anything you can look at in the universe," Dave Finley, the public information officer for the National Radio Astronomy Observatory (NRAO), which operates the VLA, told me.

The VLA is a radio telescope, a message that Finley and the NRAO are eager to have people understand. But it doesn't collect sound. It collects radio waves, which, Finley tells me, are exactly the same as light waves. Only different.

Finley explains that optical telescopes like Hubble and Palomar are designed to collect light waves, while the VLA collects radio waves. The end result is the same: To understand what's going on in the universe. And it seems that the VLA is doing a good job of that.

"The VLA is the most scientifically productive ground-based telescope in the history of astronomy," Finley said. "There are between 180 and 200 scientific papers a year that announce discoveries" based on research done at VLA.

The VLA is a project of the National Science Foundation, and as such, is available to any scientist who wants to use it, and who submits a successful proposal.

Finley explained that the NRAO receives about two hours of proposals for every hour of available time on the VLA, so it's a competitive process. But those who are accepted get access to incredible machinery.

The VLA was designed and built in the 1960s and '70s, and it was dedicated in 1980. Today, it is undergoing a multiyear process to upgrade all of the antennas from analog systems to all digital. This project, known as the Expanded Very Large Array, is expected to be completed by 2011 or 2012 at a cost of about $75 million.

Road Trip 2007 promo

Finley explained that the upgraded VLA will be 10 times more capable as a scientific instrument than it was originally.

Today, the project is well under way, with 11 of the antennas having already been upgraded, and one literally being worked on while I'm here.

It's quite a sight, actually: a giant building, known as the "barn," with one of these mammoth antennas inside it. It's kind of the astronomy version of an auto mechanic, with the antenna seemingly up on blocks and technicians banging away at it, to make the necessary changes.

One major piece of the upgrade involves switching out the old analog microwave waveguide systems--essentially pipes that signal waves traveled through--with modern fiber optics.

Another major piece is installing a new "correlator," the complex system that takes the signals from all 27 antennas and combines them into one cohesive signal.

The current correlator is an all-analog system that's going to be replaced by a new one to be donated by Canadian scientists as their contribution to the Expanded Very Large Array.

The net effect of the upgrade, Finley says, is to get the equivalent of 10 VLAs for the cost of about one-third of the original (taking the original costs and factoring in inflation).

The idea, he explained, is to keep the VLA at the forefront of astronomy for the foreseeable future.

"We've already marked our 25th anniversary," Finley said. "I'm pretty sure we'll have people here to mark the 50th."

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