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Puerto Rico's massive radio telescope is still guarding against killer asteroids

Hurricane Maria inflicted minor damage on Arecibo.

October 25, 2017 at 3:47AM

The world’s largest radio telescope, seen from the air at Puerto Rico’s Arecibo Observatory, is assisting with hurricane recovery. (The Minnesota Star Tribune)

ARECIBO, Puerto Rico – While the vast majority of Puerto Ricans are living in a technologically deprived state without power and poor communications, there's one high-tech oasis on the island that wasn't blown back to the dark ages by Hurricane Maria.

The Arecibo Observatory, a massive radio telescope built in 1963 in the mountains of central Puerto Rico, was raked by the eye of the storm but was almost unscathed.

Within seven days, the observatory was up and running on generators — tracking pulsars and receiving data from across the galaxy.

The heart of the observatory is a silvery 1,000-foot-diameter dish that sits in a valley and makes Arecibo the largest operational single-dish radio telescope in the world. China recently built a 1,650-foot-diameter telescope, but it's still not running.

The machine is composed of more than 38,778 individual reflective panels that bounce radio waves from the cosmos at an array of antennae 435 feet above the ground.

"When you see it at first it looks very fragile, but it's actually very resistant," said Francisco Cordova, its director.

When Maria slammed into the installation on Sept. 20, packing 110-mph winds, the storm tore off a few panels and broke one of the two 430 megahertz radars. But the telescope was left fully operational.

Most nonscientists know the observatory from its star turns in Hollywood. The telescope played a central role in "Contact," the 1997 movie based on a Carl Sagan novel.

In that film, the telescope receives communications from extraterrestrials 26 light-years away. In reality, in 1974, the telescope transmitted the "Arecibo Message" — a series of encoded pictures of our galaxy, man and the telescope — to the M13 star cluster 21,000 light-years away in hopes of engaging intelligent life. That message still has to travel some 20,957 years before it reaches its intended target.

In the real world, the observatory plays a dramatic role: potentially saving the planet from outright destruction.

The observatory's powerful planetary radar tracks asteroids and other near-Earth objects and can plot their trajectory a century out, said Nicholas White, vice president for science at the University Space Research Association in Columbia, Md., which helps manage the observatory.

Under a NASA program, Arecibo and other observatories are charged with giving Earthlings notice if a killer asteroid threatens.

But it's the observatory's more Earthbound properties that have made it relevant to Puerto Ricans post-Maria.

Eighty percent of the island's 3.4 million residents still don't have electricity, one-third don't have water and 40 percent can't communicate.

That's turned the Arecibo complex, which has its own power supply and water well, into something of a haven.

The installation is distributing 14,000 gallons of drinking water a day. And FEMA is using its helipad to drop off food and other critical supplies. The police and power authorities are piggybacking on its radio repeaters.

While the observatory survived the hurricane, a bigger threat might be in Washington. The National Science Foundation, which provides the bulk of the observatory's funding, is proposing to cut its budget from $8 million to $2 million over the next five years.