Polling shows that nearly half of Americans now believe aliens have visited this planet--and that the number who aren't sure has dropped by two-thirds. The reasons why, experts say, are complicated. Americans are becoming more open to the idea that aliens have visited Earth, according to a series of polls that show belief in alien visitation has been steadily on the rise since 2012. Almost half--47 percent--of Americans say they think aliens have definitely or probably visited Earth at some point in time, according to a new poll from YouGov conducted in November 2025 that involved 1,114 adult participants. That percentage is up from roughly a third (36 percent) of Americans polled in 2012 by Kelton Research, with the exact same sample size.