Arecibo Diary: The Art of Observing

By Seth Shostak

Tuesday, October 17, 2000 1:30 a.m.

"Take the con." Peter Backus smiles, and gestures toward a beat-up chair. "Twenty acres of antenna mesh, miles and miles of cable, a trailer stuffed with integrated circuits -- and it’s all yours…"

"Hard to resist…" I murmur, and sit down. It’s 6:00 p.m., and already dark outside. We’ve deliberately chosen to conduct our search at night to avoid the problem caused by signals passing too near the Sun. Charged particles from Sol can turn a narrow-band signal from an easy-to-find pure tone to a difficult-to-uncover buzz. So our hunt for ET is nocturnal. I take the early shift, from now to midnight, and then Jill Tarter presses the search until 6:00 a.m.

Peter helps me get everything started. His fingers rattle across one of the keyboards, and The System connects to the Arecibo control software. The System can now direct the positioning of Arecibo’s needle-thin beam. A second keyboard pizzicato brings Jodrell Bank on-line. We are now definitely in command. I sit back and briefly consider telling Scottie in the engine room to jack us up to Warp 6.

Peter checks the incoming signal levels as The System begins to do its thing. A bit of code called the Autoscheduler rummages through the thousands of stars in our hit list, looking for those that are in position for a search. It suggests its best choice: star 5673. I pliantly accept the Autoscheduler’s recommendation, and within seconds the telescopes’ drive motors in Puerto Rico and England growl and grind, slewing both antenna beams to cover 5673 and its surroundings.


A mass of tie-down cables anchor the antenna to the ground and set its spherical curvature.

While the scopes are being aimed, I look up the characteristics of our target, 5673. (That’s the Project Phoenix designation. Its astronomical moniker is HD 211476.) It is a G2 star, which means it’s nearly identical in size and brightness to the Sun. Its distance is 100 light-years. If you know where to look, you can see 5673 with a cheesy pair of binoculars.