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SETI
- Allen Telescope Array
- Optical SETI
- Interstellar Message Construction
- Project Phoenix 1995-2004
- Background Science
- History of SETI
- Center for SETI Research Team
- Other people doing SETI
- Hollywood's View of SETI
Other Intelligent Life at the Observatory
by Dr. Peter Backus, Observing Programs Manager
The details of SETI observing are engrossing--so much so that when we launch a Phoenix observation run, it is all too easy to forget that the enormous dish just beyond the control room is actually used by others as well. While I shouldnt be surprised to see old friends on the observatory grounds, seeing my friend Joel Weisberg and two of his Carleton students at breakfast was an unexpected pleasure, and reminded me that the human universe we observe at Arecibo is just as rich and compelling as the one we scan for signals.
Joel was a postdoctoral fellow at the University of Massachusetts while I was a graduate student there. We both studied pulsars and even collaborated on a paper or two. Weve corresponded occasionally in the years since UMass, but it has been a genuine and unexpected treat to see him at Arecibo those few times Phoenix observing has overlapped with one his pulsar-observing runs. Each reunion gives us a chance to really catch up, and I especially enjoy hearing the latest news about pulsars.
Joel isnt my only source for the inside scoop on pulsars. I often have lunch with Paulo Freire, a research associate here at the observatory. Paulo studies many aspects of pulsars, but his specialty is finding and studying rapidly spinning pulsars in globular clusters. It is fun to hear him discuss how he uses the pulsars to explore the clusters physics.
Sometimes, its not people but planets that provide a break from the routine. For a few nights this week, our usual 5 PM to 8 AM schedule will have a four-hour interruption while planetary astronomers bounce a radar pulse off Saturns moon Titan. The slow dance of the planets brings the Earth and Saturn about as close as they ever get this week. If observing time is precious, seizing a rare opportunity for research is priceless, and the excitement is contagious!
Amazingly, a radar pulse from Arecibo can travel 748 million miles (1.2 billion km) to Titan, then retrace the journey back to Earth with power enough to reveal information about the surface of that cold, distant moon. The round trip journey of this pulse just fits within the relatively small observing window defined by the telescopes limited ability to move. Titan is about at the distance limit for Arecibo, which can follow a star or planet across the sky for at most two hours and forty six minutes. It takes about two hours and fifteen minutes for a radar pulse, traveling at the speed of light, to make the round trip to Titan and back. So, the pulse is transmitted just after Titan rises into view and the return pulse is received just before Titan sets. There is a certain beauty in the neat match of needs and capabilities in this project.
While the Titan Interlude in our observing was scheduled months ago, other events take us by surprise. Weather, for example, cannot be predicted far enough in advance to consider in our observing plans. Tropical Storm Odette was a big surprise for everyone. Well past the season for such storms, she suddenly appeared, heading straight for Haiti and the Dominican Republic, our neighbors to the west. Bad news for the inhabitants of those countries, but the storm presented a terrific observing opportunity for atmospheric scientists here at Arecibo. We willingly gave up precious hours for these time-critical studies that could perhaps save lives in the future. It is raining here as I write this. I can only imagine what its like to the west.
Fortunately, the rain doesnt affect radio astronomy, at least at the frequencies used at Arecibo, so Murray Lewis is studying Hydroxyl (OH) masers now. Later there will be a pulsar experiment, and then more radar observations of Odette. While the signal from out there remains elusive, all around me is a wide variety of intelligent life right here at the observatory. A pleasant thing to contemplate as we wait our turn for the control room!