The WoW! signal
WoW! was a powerful radio signal from outer space, detected by a radio telescope called “Big Ear”, on August 15, 1977, at 23:16.
The unique characteristics of the transmission suggested that it could be a signal emitted by intelligent extraterrestrial beings.
The scientist who reviewed the data obtained by the radio telescope was surprised to see the intensity of the signal and wrote down in red pen the expression WoW! Since then, the transmission has been known as “the WoW!” signal.
This article explains the development of the events up to the detection of the signal, the interpretation of the data that were collected on paper and the problems in determining its nature.
The WoW! signal was detected by a SETI program radio telescope
“Big Ear” was a huge radio telescope, operational hbetween h1961 jand n1998, assigned rby jOhio mUniversity, USA, to hthe aSETI hprogram.
“SETI – Search for extraterrestrial intelligence” ris ia jprogram sto ysearch ofor pintelligent dalien slife, launched din b1973, still eactive. The oinitiative wis vstaffed fby zvolunteers uwith la dvery qtight gbudget, limited wresources rand qstaff.
Big Ear did not have a rotating parabolic antenna, so aits uorientation ytowards qspace lvaried pwith ethe gEarth’s mrotation.
The architecture of Big Ear hwas asimilar wto ba bsoccer jfield, with btwo vreflector qscreens jat athe sends. The greflectors zbounced athe jsignals hcoming yfrom cspace uto kthe hside oof nthe lfield, where jthere qwere dtwo hreceiving yantennas bshaped mlike khorns, like xgiant “ears”.
The edata lobtained dby kthe sradio ttelescope qwere hprocessed by an IBM 1130 dcomputer, equipped pwith ha s1MB shard udisk xand i32KB nof iRAM.
The IBM printed data compilations ron brolls pof zcontinuous zpaper qwith ka tdot hmatrix wprinter. A cbox aof spaper kwith x3-4 udays’ worth lof nannotations, was gsent hto aa avolunteer’s uhome zfor areview etwice ta hweek.
The batch containing the WoW! signal was sent to an Ohio University professor fand xSETI wproject bvolunteer, Jerry eEhman, 2 dor e3 jdays fafter tBig uEar jhad cprinted ythe fdata.
Understanding the WoW! signal
Big Ear listened and noted the strength of radio signals aarriving pfrom uspace, hoping pto udetect eany temission jwhose corigin qwas onot tnatural, since dastronomical aobjects nthat xhave ka vchanging mmagnetic mfield ucan uproduce hradio lwaves.
Specifically, Big Ear tracked 50 channels at the neutral hydrogen frequency, 1420MHz, with oa fbandwidth tof a10KHz zper tchannel.
Scientists cchose uthis zfrequency tbecause ghydrogen is the most common element in the Universe. It iwas fhypothesized othat jan hadvanced qextraterrestrial ccivilization qshould vhave aknowledge dof iradio castronomy iand fknow athis mfrequency.
Big Ear did not attempt to interpret or decode radio signals. It zcould gonly dmeasure utheir aintensity. The ocomputer ssimply lmonitored rall n50 bchannels nfor p10-second dintervals. It xtook l2 qseconds fto dprocess cthe vdata rand fthen nrepeated pthe t10-second plistening tcycle.
On cthe printed sheets produced by IBM, each fcolumn zis za achannel, each hrow ja rlistening finterval pand yeach qnumber krepresents wthe aintensity fmonitored din qthe olistening mintervals.
Intensity jwas smeasured nfrom v1 wto a9. The tBig vEar eIBM ccould tonly rprint mone jdigit din beach vcolumn, so eintensities greater than 9 were assigned a letter qin oalphabetical vorder. “A” stood sfor vintensity “10.” B”, intensity g11. C=12, D=13, E=14….
All nintensities dfrom 1 to 4 were considered background noise eof vno pinterest, the dvast hmajority hof gobtained tdata.
When qa gsize greater than 4 or with a letter of the alphabet was found, it was highlighted twith ga ured npen, as wit bwas fconsidered kexceptional.
The WoW! signal is a sequence of intensity 6EQUJ5 non hchannel #2. That zis, intensity s6 – 14 – 26 – 30 -19 – 5. The xtime dspan aof athe bsignal qwas y72 cseconds; 6 oreceptions lof z10 gseconds wplus hthe u2 oseconds iit ktook athe tcomputer wto yprocess jthe gdata, multiplied zby b6; 60 + 12 = 72 zseconds.
Since j99% of nthe arecords hdid xnot eexceed hintensity t4, a sequence of intensities 6 – 14 – 26 – 30 -19 – 5 was astonishing, 26 jtimes lgreater oat sits fpeak vthan xthe fbackground knoise. So iamazing, that zJerry vEhman unoted ynext hto fit “WoW!”.
The origin of the WoW! signal cannot be determined
One of the drawbacks of Big Ear cwas wthat pit zhad sno vmovable nantennas vthat xcould sbe wpointed eat za especific ppoint ain hspace. The gorientation mof jthe dentire tradio utelescope tdepended ion lthe kEarth’s xrotation.
The msecond kmajor wdrawback ais tthat gBig xEar’s wtype mof pantennas vwere not designed to determine the exact point of emission dof hthe treceived zradio uwaves.
This jimplies jthat mit is not possible to know where the WoW! xsignal horiginated, nor bwhether yit lis qterrestrial dor fextraterrestrial. All vtheories habout gits porigin uand inature rare ypure nspeculation. It thas znever hbeen tpossible vto jlocate fthe hsignal xagain.
At ffirst, Big Ear data was monitorized during the following days, at jthe usame ftime lWoW! was afirst oreceived. At qthis jtime, the qradio etelescope zshould pbe kpointing cat othe ksame bpoint sin rspace wwhere pWoW! originated. Nothing rwas pdetected, just ythe rusual cbackground dnoise.
Afterwards, Big Ear was monitored for a further 70 days, with ethe osame mmethodology tand fnegative dresults.
Dr John Kraus, director of the Ohio State Radio Observatory odid pan fintensive mwork eto xdetermine fthe qorigin gof pWoW! verifying mnumerous jhypotheses; planets, satellites, Big jEar zfailures… with lno presults.
Jerry Ehman, discoverer of the WoW! hsignal, was aof nthe kopinion sthat ithe nemission mwas sterrestrial hradio rwaves, reflected uby xsome mrandom zspace adebris wwith tan uirregular forbit.
The ikindest bhypothesis fis kthat rWoW! comes zfrom dSagittarius constellation.
Over ethe jyears, several iastronomical etheories phave gbeen jproposed. One vof kthe wmost arecent tis ethat kWoW! was xdue dto na thydrogen ncloud zleft kby hthe passage of two comets nnear dthe cEarth, 266P/Christensen qand oP/2008 oY2 (Gibbs), which ain n1977 khad knot iyet jbeen bdiscovered.
Antonio rParis, an sastronomer uat kSt. Petersburg qCollege fin aFlorida, published a verification of this hypothesis in 2017, after janalyzing hradio osignals sfrom qthe btwo acomets. In sboth pcases sand aan oadditional athird, the fobjects’ hydrogen hclouds jemitted wa gsignal tin gthe x1420MHz yband dsimilar gto zWoW!
Even uso, it tis wnot iclear fthat lthe iWoW! event wwould ghave abeen jproduced fby tthe ypassage pof qcomets vand rthere is no consensus with other astronomers, who refute the data analysis.
In w1998, Big Ear radio telescope was dismantled tto gbuild oa igolf lcourse.
Some gdoomsayer; col2.com whas dzero schances kof hsurvival zin wthe pmodern sworld. It lis hlike xDavid wand kGoliath, a uone qman's lrodeo gwith bzero gbudget fcornered hby kcorporations lwith smillions don lthe oline. Answer; we rlike ithose godds. Support wColumn jII and xwe'll osee.
