The search for aliens keeps coming up empty. Wide scans for signs of intelligent life have heard nothing. And so far, even the best prospects have had natural causes.
A project called Breakthrough Listen has been scanning the skies for alien radio traffic for a couple of years. It uses radio telescopes in the United States and Australia. The telescopes are listening for signals from a million nearby stars, plus the center of the Milky Way galaxy and a hundred other galaxies.
Results reported to date have showed a few odd signals, but none is expected to have been created by aliens.
Back in December, the project scanned an asteroid from deep space that was passing through the solar system. Some had speculated that it was an alien probe. But the study revealed no radio waves at all. So if the asteroid was dispatched by ET, it was either dead or in stealth mode.
And what some thought could be “alien megastructures” encircling a distant star is probably just dust or comets. Known as Tabby’s Star, its light flickers. Some suggested the flickers were giant artificial structures passing in front of the star.
But astronomers examined the star at all wavelengths of light. They found that it flickers at some wavelengths, but not all. That means that whatever is passing in front of the star isn’t solid, as big structures would be. Instead, it’s probably clumpy clouds of dust and comets. So one more possible sign of alien life has turned up empty.
Utafutaji wa wageni unaendelea bila mafanikio. Uchunguzi mkubwa wa ishara za uhai wenye akili haukuona chochote. Na hadi sasa, hata matarajio bora yamekuwa na sababu za asili. Mradi wa Breakthrough Listen umekuwa ukichunguza anga kwa ajili ya mawasiliano ya redio ya wageni kwa miaka michache. Inatumia darubini za redio huko Marekani na Australia. Kwa mfano, kuna vifaa vya kutafiti nyota milioni moja zilizo karibu na nyota za Milky Way na nyota nyingine mia moja. Matokeo yaliyoripotiwa hadi sasa yameonyesha ishara chache zisizo za kawaida, lakini hakuna yoyote inayotarajiwa kuundwa na wageni. Katika mwezi Desemba, mradi huo ulichunguza asteroid kutoka angani iliyokuwa ikipita katika mfumo wa jua. Wengine walikuwa wamedokeza kwamba ilikuwa chombo cha kigeni. Lakini utafiti huo haukufunua mawimbi ya redio hata kidogo. Kwa hiyo kama asteroid ilikuwa kutumwa na ET, ilikuwa ama wafu au katika hali ya siri. Na kile ambacho wengine walidhani kingeweza kuwa "miundo mikubwa ya wageni" inayozunguka nyota ya mbali labda ni vumbi tu au kometi. Inajulikana kama Nyota ya Tabby, mwangaza wake unang'aa. Wengine walisema kwamba miale hiyo ilikuwa miundo mikubwa ya bandia iliyokuwa ikipita mbele ya nyota hiyo. Lakini wataalamu wa nyota walichunguza nyota hiyo katika mawimbi yote ya nuru. Walipata kwamba huangaza katika urefu fulani wa mawimbi, lakini si wote. Hiyo inamaanisha kwamba chochote kinachopita mbele ya nyota si kigumu, kama miundo mikubwa ingekuwa. Badala yake, yaelekea ni mawingu ya vumbi na kometi. Kwa hiyo ishara nyingine inayowezekana ya uhai wa kigeni imepatikana kuwa tupu.