Formorethantwentyyearsscientistshavebeensearchingforsig...
問題詳情:Formorethantwentyyearsscientistshavebeensearchingforsignsoflifeonotherplanets.Mostofthesesearcheshavebeendoneovertheradio.Thehopeisthatsomeoneinouterspacemaybetryingtogetintouchwithus.Scientis...