Right after the upcoming Rapture the antichrist is not about to quote from the Bible to give the correct explanation for the Rapture! LOL! That would be hilarious, but he ain't going to do that! Those left on the earth after the Rapture will be deceived and totally fall for the false "alien explanation". A few, however, will wisen up and accept the Lord, and those numbers will increase during the Tribulation, though the antichrist will put many to death.
Neil
P.S. This is a very short video about Israel and the "aliens".