SETI Institute

Home News About us SETI Carl Sagan Center Education and Public Outreach Publications Support us teamseti

Project Phoenix April 2003 Observing Wrap-up

April, 29 2003

by Peter Backus - Manager, SETI Observing Programs

In five hours, our final night of observing will be over. It’s hard to believe that we started observing over two weeks ago. Thirteen nights at fifteen hours per night have gone by quickly. Somewhere in those two weeks we had two days off. They say time flies when you’re having fun. When you’re also very busy, it zips by even faster.

This was our first (and last) use of the New Search System (NSS) in two-site mode. In November, a hardware problem in the NSS at Jodrell Bank prevented us from getting more than a few hours of data on the radio frequency interference (RFI) environment in England. Now, with that problem solved, we got to experience what we had only glimpsed before. The amount and strength of the interference was more than we expected. While that is bad news for searching for an ET signal, it is not too bad for confirming a signal. Since we only use the data from the Lovell Telescope to look for a signal with specific characteristics, we can observe through much of the interference.

Observing is what we do, in many ways. Each night as we observed the target stars, the engineers at both sites observed the system. Every aspect of system performance was studied. Was the frequency tuning correct? Was the star selected the best choice and was it observed for an appropriate amount of time? Did the database handle the signal descriptions and classifications correctly? On and on, they looked deeper into the workings of the system. The lessons learned at night would result in improvements the next day. Every night the system performed a little better. Sometimes it would be subtle, perhaps the way information was displayed. Sometimes it was a fix to a serious problem, e.g., a communications error between computers at the two sites.

The main scientific goal of this run (aside from detecting ET) was to “finish up” as many stars as possible in the frequency range from 1200 MHz to 1750 MHz. Since the old Targeted Search System observed 10 MHz bands of the spectrum, a strong signal could block out that much even though it didn’t cover the 10 MHz. The NSS, with Programmable Detection Modules processing 2 MHz, allows us to recover some of the spectrum that we had to skip before. The desire to search as much spectrum as possible derives from the origin of Project Phoenix, the terminated NASA SETI Program. The NASA Targeted Search planned to observe about 800 stars in the frequency range from 1000 to 3000 MHz.

Since we came to Arecibo in 1998, we have been observing in the 1200 to 1750 MHz range because the Lovell Telescope at Jodrell Bank could not operate at higher frequencies. As Project Phoenix wraps up, we will give up two-site observing, and will switch to observing in the range from 1750 MHz to 3000 MHz at Arecibo. We will try to achieve the original NASA goal in our remaining observing time, roughly 500 hours.

After thirteen nights we’ve learned a lot. We know a lot more about how to search with the NSS. Tomorrow, we pack up much of our equipment for shipping back to the lab in California. Next week we’ll consider the lessons we’ve learned and start to double the bandwidth of the system. Our next observing run is likely to be in November, just over six months away. It sounds like a long time, but there’s much to do. Time will zip by.

So far during this run we’ve observed for nearly two hundred hours. We haven’t found The Signal, but we have five hours left.