The newly upgraded Arecibo Observatory
by Robert Sanders
Berkeley researchers have begun a new era in their ongoing search for extraterrestrial intelligence. They have installed a new search instrument, some 40 times more powerful than their previous machine, at the newly upgraded Arecibo Observatory in Puerto Rico the world's largest radio telescope. The new machine, dubbed SERENDIP IV, is the fourth-generation machine in their 20-year-long program.
"We've been searching the sky for signs of extraterrestrials with continuously increasing capability," said Stuart Bowyer, professor in the graduate school and principal investigator of the SERENDIP program, a project he began some 20 years ago. "So far-nothing. But we're not giving up."
Dan Werthimer, codirector and principal designer of the SERENDIP IV machine, points out that "the machine has the equivalent power of 200 of the world's largest supercomputers working together on this task." The Arecibo telescope has just completed a $25 million upgrade with funds provided by the National Science Foundation and the National Aeronautics and Space Administration. This upgrade will substantially increase the telescope's capabilities for research in radio astronomy. Mike Davis, project scientist for the Arecibo upgrade project and a SERENDIP co-investigator, says the upgrade will significantly enhance the search effort.
SERENDIP stands for Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations. Jeff Cobb, the Berkeley researcher in charge of dealing with the huge amount of data produced by the SERENDIP IV machine, has developed extensive computer programs to sort through these data to identify promising candidate signals among the false alarms produced by human activities.
Reprinted from the Berkeleyan/July 16-August 19,1997
SETI--looking and listening for someone out among the stars--is a great adventure. Developing the means to do so is an adventure of its own. Two scientists from Project SERENDIP, Dan Werthimer and Jeff Cobb, and volunteer scientist Dave Anderson recently traveled to Puerto Rico to install the 168 million-channel SERENDIP IV instrument at the Arecibo Observatory. The installation coincided with the dedication of the observatory's newly renovated telescope. Here, with the help of notes made at the time, is the story of their adventure.
After months of hard work and the assistance of several volunteers at the U.C. Berkeley Space Sciences Laboratory who proved themselves capable of moonlighting as professional movers, the components of SERENDIP IV were ready to roll. Packed into eleven large boxes were a PC, a workstation donated by Sun Microsystems, 40 high-speed processors, and cardcages, various oscillators and filters, and countless cables.
Twenty hours later, courtesy of Federal Express, the eleven boxes were stashed outside the control room at Arecibo. Leaving at 4:30 a.m. June 11, 1997, Dan, Jeff, and Dave flew to steamy San Juan and although briefly confused by the mountain roads, eventually arrived at the observatory. After a night's sleep punctuated by the sound of "coquis" (tree frogs), an incredibly loud and varied symphony, and a breakfast of farina-like hot cereal cooked with milk and flavored with cinnamon, they were ready to begin unpacking. Greeting them were one rickety table (soon replaced), a leftover rack from a mainframe computer, and some unstrung cables. Clever and ingenious (requirements for SERENDIP workers), they soon figured out how to make-do with available resources, for example fitting a synthesizer behind a filter at the top of the rack, on wood blocks to keep cool. The Arecibo staff were a great help as well.
The next few days were spent testing the hardware, which had been largely designed and built by Dan; Jeff also tinkered with his data collection software to adjust the bandwidth control, and Dave worked on a Web site that shows two-or three-dimensional graphs of the data from the instrument.
Eventually, all the components of SERENDIP IV were in place, plexiglass front panels installed and side panels put on, to produce a quite physically attractive instrument. To everyone's great relief, everything worked. SERENDIP IV had begun to listen! Equipment from SERENDIP III also had to be packed, ready to return to the U.S. and be shared with other groups involved in SETI.
Although they worked very long hours, Dan, Jeff, and Dave managed some time to meet friendly Puerto Ricans, enjoy beaches and beachgoers, do some snorkeling, and hike through the mountains and jungle surrounding Arecibo. The terrain is limestone karst, eroded by underground water flow, creating an egg-carton effect of dramatic peaks and depressions. One of these bowls houses the aluminum dish, 1000 feet in diameter, of the radio telescope, the world's largest. Climbing on ladders and catwalks to and from the platform above the dome is not for the faint of heart!
Besides facilities for permanent staff, summer students, and visiting scientists, Arecibo maintains a dramatic visitor center and science museum. They are interested in doing a SERENDIP display on our project.
The inauguration ceremony for the renovated telescope was quite an occasion, with speeches by the governor of Puerto Rico and the director of the National Science Foundation, among others. Greetings from Frank Drake were read by Jill Tarter of the SETI Institute.
Tired but pleased with the results of their trip, our adventurers returned to Berkeley, ready to continue the search we all find so fascinating.
Over the last eighteen years, the SERENDIP I, II and III instruments have been used to carry out very cost-effective piggy-back SETI searches at several of the world's largest radio telescopes.
There has been a tremendous growth in SERENDIP instrumentation since its inception. SERENDIP I utilized a 100-channel spectrum analyzer on 25 and 65 meter telescopes. SERENDIP II's 65,536-channel spectrum analyzer was used primarily on the National Radio Astronomy Observatory's 90 meter telescope in West Virginia. During recent years, SERENDIP III's four million-channel analyzer has been used to carry out a systematic sky survey on the National Astronomical and Ionospheric Center's 305 meter Arecibo telescope. The newest generation SERENDIP IV instrument deployed this June at Arecibo has 168 million channels. The number of channels in a SERENDIP system has improved by a factor of 1.6 million over eighteen years. During this period of increased capacity, the size and cost of the instruments have remained roughly constant. Each generation of SERENDIP instrumentation has fit into a standard electronic instrument rack. The SERENDIP IV 5-year piggyback sky survey will cover all of the Arecibo sky (approximately 30% of the total sky) five times, with a dedicated receiver focused on frequencies near the hydrogen 21 cm. line.
The new spectrum analyzer covers a 100MHz bandwidth with a 0.6Hz resolution and a 1.7 second integration time. Its modular design incorporates a band of digital mixers and filters to separate the 100MHz band into forty 2.5MHz sub-bands. Each 2.5 MHz sub-band is further broken down into 0.6 Hz bins by means of a four-million point fast Fourier transform. The resulting power spectra are analyzed by forty high speed processors. Narrow band signals having power significantly above background noise levels are recorded along with telescope coordinates, time, and frequency. The data are sent in real time to Berkeley for analysis.
In addition to the launch of SERENDIP IV, we are currently engaged in the construction of smaller versions of the SERENDIP IV instrument for groups in Australia and Italy and in the development of a “Seti@Home ” program which will allow volunteers to aid in the analysis of SERENDIP IV data using their computers at home.
Since congress cut off funding for SETI in 1993, the SERENDIP project has been entirely supported by private funds. Especially noteworthy is the support of the SETI Institute and the Planetary Society, founded by the late Carl Sagan. SERENDIP has also received generous contributions from the Friends of SERENDIP, Toshiba America, Sun Microsystems, Xilinx and Intel Corp.
Friends of SERENDIP are vitally important in insuring that newly acquired data will be subject to the most sophisticated and exhaustive data analysis. Will you help with your generous support?
If you would like to make a tax-deductible contribution to SERENDIP, please see our donor form.
Arthur C. Clarke, Chair, Author, Inventor, Futurist.
Frank Drake, Professor of Astronomy and Astrophysics, U.C. Santa Cruz; President SETI Institute, Mountain View.
Jean Heidmann, Astronomer, Observatoire de Paris, France.
Jun Jugaku, Professor of Astronomy, Tokai University, Japan.
Philip Morrison, Institute Professor MIT.
Carl Sagan (1934 - 1996), Astronomer, Author.
Glenn Seaborg, Nobel Laureate, Professor U.C. Berkeley.
Charles Townes, Nobel Laureate, Professor, UC Berkeley.
Jack Welch, Professor of Astronomy, Radio Astronomy Lab U.C. Berkeley.