In 2017, a weird-looking space object called ʻOumuamua whipped past our sun. Now a Harvard scientist is suggesting it miiiight be an alien probe! So we’re revisiting this episode from a few years ago, where we ask: could aliens actually exist? Is there any chance they’ve visited Earth already? We talked to astronomers Dr. Jill Tarter, Dr. Seth Shostak, investigative journalist David Clarke, and physicist Prof. Jim Al Khalili. Check out the transcript here: http://bit.ly/2QlCqSf This episode was originally produced by Kaitlyn Sawrey, Wendy Zukerman and Rose Rimler with help from Shruti Ravindran and Meryl Horn. Nick DelRose helped produce the updated version. Fact Checking by Michelle Harris, Meryl Horn and Nick DelRose. Music by Bobby Lord and Emma Munger, mixed by Emma Munger and Bumi Hidaka. Editing by Blythe Terrell. Additional editing help from Caitlin Kenney. Also thank you to Dr. Ravi Kumar Kopparapu, Dr. Craig O'Neill, Dr. Jessie Christiansen, Dr. Cameron Hummels, Dr. Phil Hopkins, Dr. Avi Loeb, and the many other researchers who helped us on this.