A polarizing Harvard astronomer has been appointed to lead a White House panel studying UFOs. Avi Loeb is leading a new Science Advisory Council tasked with finding the origin of unidentified objects spotted by military pilots and others. It’s part of a broader White House effort studying possible national security risks posed by UFOs. Loeb’s theories have won praise in UFO circles but put him at odds with other astronomers who say he jumps to exotic conclusions. Loeb said he’s taking a grounded approach with the White House work, assuming unidentified objects are human-made unless evidence proves otherwise.