"Long before it's in the papers"
January 28, 2015


Search for ET beefed up—with your help

Jan. 2, 2008
Courtesy University of California - Berkeley 
and World Science staff

The longest-running search for ra­di­o sig­nals from al­ien civ­il­iz­a­tions is get­ting a burst of new da­ta from an up­grad­ed tel­e­scope. 

That means dramatically im­proved search ca­pa­bil­i­ties, proj­ect sci­en­tists say—but the full ben­e­fits will be real­ized only with pub­lic par­ticipa­t­ion. They’re are call­ing for new vol­un­teers for SETI@home, a proj­ect in which or­di­nary cit­i­zens do­nate un­used time on their com­put­ers to let the machines help comb through the search da­ta.

The world's larg­est single-dish ra­di­o tel­e­scope, the Are­ci­bo Ob­serv­a­to­ry in Puerto Rico is one of the larg­est cen­ters for re­search in ra­di­o as­tron­o­my. The huge "dish" is 1000 feet (305 me­ters) wide, 167 feet (51 me­ters) deep and co­vers about 20 ac­res (0.08 square km). (Cred­it: NAIC Are­ci­bo Ob­serv­a­to­ry/NSF)

“The next genera­t­ion SETI@home is 500 times more pow­er­ful then an­y­thing an­y­one has done be­fore,” said proj­ect chief sci­ent­ist Dan Wer­thi­mer. “That means we are 500 times more likely to find” al­ien life—if enough new vol­un­teers join. Even if not, the up­grades still prom­ise an im­prove­ment of at least about 100-fold, he said.

Since it launched eight years ago, the Un­ivers­ity of Cal­i­for­nia, Berkeley-based SETI@home has signed up more than 5 mil­lion in­ter­est­ed vol­un­teers, ac­cord­ing to proj­ect sci­en­tists. It boasts the larg­est com­mun­ity of ded­i­cat­ed users of any In­ter­net com­put­ing proj­ect, they said: 170,000 devo­tees on 320,000 com­put­ers. This num­ber of com­put­ers should rise by an ad­di­tion­al mil­lion to han­dle the ex­pand­ed da­ta flow, Wer­thi­mer said.

SETI stands for Search for Ex­tra­ter­res­tri­al In­tel­li­gence. Pro­s­pec­tive vo­lun­teers are be­ing asked to visit the SETI@home web­site for in­for­ma­tion.

The in­creased amount of da­ta is a re­sult of new and more sen­si­tive re­ceivers and oth­er im­prove­ments to the world’s larg­est ra­di­o tel­e­scope in Are­ci­bo, Puerto Rico, said proj­ect lead­ers. The soft­ware used for the job, they added, has been has been up­grad­ed to deal with the surge of in­for­m­a­tion.

Ac­cord­ing to proj­ect sci­ent­ist Er­ic Ko­r­pela, the new da­ta amounts to 300 gi­ga­bytes per day; on a yearly basis that adds up to the amount of da­ta stored in the U.S. Li­brary of Con­gress. “That’s why we need all the vol­un­teers,” he said. “Ev­ery­one has a chance to be part of the larg­est pub­lic-par­ticipa­t­ion sci­ence proj­ect in his­to­ry.”

The 1,000-foot wide Are­ci­bo dish, which fills a val­ley in Puerto Rico, is part of the Na­t­ional As­tron­o­my and Ion­o­sphere Cen­ter ope­rated by Cor­nell Un­ivers­ity in Ith­a­ca, N.Y. Since 1992, Wer­thi­mer and his team have used ra­di­o ob­serva­t­ions at Are­ci­bo to rec­ord sig­nals from space and an­a­lyze them for pat­terns that could in­di­cate they were trans­mit­ted by a civ­il­iz­a­tion.

When the team’s in­com­ing da­ta over­whelmed its abil­ity to an­a­lyze it, the sci­en­tists con­ceived a “dis­tributed com­put­ing” proj­ect to har­ness many com­put­ers in­to one big supe­rcomputer to do the anal­y­sis. Since SETI@home was launched, oth­er dis­trib­ut­ed com­put­ing proj­ects have aris­en, from fold­ing@home to pre­dict the struc­tures of or­gan­ic molecules, to the newly-launched cos­mol­o­gy@home to mod­el pos­si­ble un­iverses. Most share the SETI@home plat­form.

“Un­til now, there has been enough com­put­ing pow­er to go around,” Wer­thi­mer said. What largely trig­gered the new flow of da­ta was the ad­di­tion of sev­en new re­ceivers at Are­ci­bo, which let the tel­e­scope rec­ord sig­nals from sev­en re­gions of the sky sim­ul­ta­ne­ous­ly in­stead of one, he added.

“The mul­ti­ple re­ceivers help us weed out in­ter­fer­ence bet­ter” and re­duce the chance of mis­tak­ing earthly sig­nals from al­ien ones, he said. No tell­tale sig­nals from an in­tel­li­gent civ­il­iz­a­tion have yet been iden­ti­fied.

“Earth­lings are just get­ting started look­ing at the fre­quen­cies in the sky; we’re look­ing only at the cos­mic­ally bright­est sources, hop­ing we are scan­ning the right ra­di­o chan­nels,” Wer­thi­mer said. “The good news is, we’re en­ter­ing an era when we will be able to scan bil­lions of chan­nels. Are­ci­bo is now op­ti­mized for this kind of search, so if there are sig­nals out there, we or our vol­un­teers will find them.”

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The longest-running search for radio signals from alien civilizations is getting a burst of new data from an upgraded telescope. That will mean a massive improvement in search capabilities, project scientists say—but its full benefits will be realized only with public participation. The scientists are calling for more volunteers for SETI@home, a project in which ordinary citizens donate unused time on their computers so that the machines can help comb through the search data. “The next generation SETI@home is 500 times more powerful then anything anyone has done before,” said project chief scientist Dan Werthimer. “That means we are 500 times more likely to find” alien life—if enough new volunteers join. Even if not, the upgrades still promise an improvement of at least about 100-fold, he said. Since it launched eight years ago, the University of California, Berkeley-based SETI@home has signed up more than 5 million interested volunteers, according to project scientists. It boasts the largest community of dedicated users of any Internet computing project, they said: 170,000 devotees on 320,000 computers. This number of computers should rise by an additional million to handle the expanded data flow, Wertimer said. SETI stands for Search for Extraterrestrial Intelligence. The increased amount of data is a result of new and more sensitive receivers on the world’s largest radio telescope in Arecibo, Puerto Rico, and other improvements, said project leaders. The software used for the job, they added, has been has been upgraded to deal with the surge of measurements. According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day, or 100 terabytes (100,000 gigabytes) per year, about the amount of data stored in the U.S. Library of Congress. “That’s why we need all the volunteers,” he said. “Everyone has a chance to be part of the largest public-participation science project in history.” The 1,000-foot wide Arecibo dish, which fills a valley in Puerto Rico, is part of the National Astronomy and Ionosphere Center operated by Cornell University in Ithaca, N.Y. Since 1992, Werthimer and his team have used radio observations at Arecibo to record signals from space and analyze them for patterns that could indicate they were transmitted by a civilization. When the team’s incoming data overwhelmed its ability to analyze it, the scientists conceived a “distributed computing” project to harness many computers into one big supercomputer to do the analysis. Since SETI@home was launched, other distributed computing projects have arisen, from folding@home to predict the structures of organic molecules, to the newly-launched cosmology@home to model possible universes. Most share the SETI@home hardware. “Until now, there has been enough computing power to go around,” Werthimer said. What largely triggered the new flow of data was the addition of seven new receivers at Arecibo, which now allow the telescope to record radio signals from seven regions of the sky simultaneously instead of one, he added. “The multiple receivers help us weed out interference better” and reduce the chance of mistaking earthly signals from alien ones, he said. No telltale signals from an intelligent civilization have yet been found. “Earthlings are just getting started looking at the frequencies in the sky; we’re looking only at the cosmically brightest sources, hoping we are scanning the right radio channels,” he said. “The good news is, we’re entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them.”