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Telescope Guests

March 05, 2004

by Dr. Seth Shostak, Senior Astronomer

Every week, more than a thousand tourists come to this observatory, to peer in amazement at 18 acres of aluminum panels stretched out in the Puerto Rican sun.  Thanks to hard-wired tourist genes, every one of them feels obliged to be photographed facing the camera, with their backs to the scope.  This conveys the idea that they have confronted and subdued this massive natural object, much in the way that similar photos next to large mountains, deep canyons, and big fish do.

The tourists shuffle through the Arecibo Visitors Center like ball bearings in a pachinko machine, moving from the shop and science exhibits to the sweeping, backyard patio.  On this concrete verandah, with its first-rate views of the telescope, the tourists can enjoy an ice cream bar while making those obligatory victory photos. 

Three hundred yards to the south hangs the intricate telescope feed platform, nearly 1,000 tons of steel and aluminum held prisoner by suspension cables as thick as your upper arm.  At this distance, its hard to judge the platforms scale, or for that matter, the scale of the dish.  To do that, you need the up-close-and-personal views of the insiders tour.

Such tours have come fast and furious during this run.  After all, were in the middle of  our last planned deployment to Arecibo, and many of the Institutes Board Members and major donors are availing themselves of a final chance to visit the telescope while Project  Phoenix is underway.

When telescope operations permit, I take these guests up to the feed platform for the scenery, and for a better sense of the massive kit thats necessary to precisely guide radio signals into the receivers.  There are two ways to reach the platform: the catwalk and the cable car.  The first is straightforward, and can be used at any time, but induces occasional arrhythmia in the infirm, and profuse sweating in anyone over the age of ten.  So we use the cable car the vehicle in which James Bond battled a baddie in the movie Goldeneye.  The cable car offers a five minute ride in an open-mesh steel box, taking you upward and outward over a sea of aluminum.

Once on the platform, the filigree lattice work seen from the Visitors Center is revealed as a matrix of heavy-duty beams, locked together by ranks of rivets.  This is the type of assembly found in bridges.  Descending to the movable structures to which the receivers are fixed is like entering the heart of a giant machine.  Industrial-grade motors drive hundreds of tons of steel in clockwork motions, so the receivers can keep pace with the slow, diurnal whirl of the heavens.

The vistas from the feed platform are spectacular, but even the jaded are blown away by the views under the dish.  To provide these, we walk our guests down a steep, narrow road, entering a magical place under an aluminum sky.  Its an eerie landscape of tie-down cables strung to concrete piers, set among green ferns.  The whole is washed by weak sunlight filtering through a half-billion panel holes.  Large lizards hurry out of our way. 

Most tours end up in the SETI control room, watching the data glide by.  The visitors, seated in a small fleet of desk chairs, crowd around the display monitors like moths stuck on a street lamp.  It is a truth universally acknowledged that every visitor reckons that THE SIGNAL will come in while theyre watching.  Consequently, each twitch on the screen is earnestly scrutinized and queried.  After a few hours of this, however, the visitors come to realize that unlike in the movies success in our hunt for signals will require extended patience.

Ben Franklin may have had problems with guests, but we dont.  They support us in a multitude of ways, and were always pleased to be able to show them what we do.  Their questions about how it all works frequently cause me to think afresh about how we might improve our experiment.  And someday I hope to welcome another kind of visitor one that makes its distant presence known by inciting the electrons in our telescopes aluminum skin to gently dance a dance that would initially catch our attention as mere numbers on a screen, but would ultimately change the world.