After eight seasons, the biggest superstar is finally stopping by for the very first time -- the sexy MATT DAMON! Not only has the Oscar-winning actor been in some of the best films ever, he's an incredible humanitarian. He's also quite the funny guy -- and he's ready to have some fun! One of Ellen's favorite guests, Science Guy STEVE SPANGLER is back -- and he's bringing more of his amazing science experiments. Ellen never knows what to expect, so whether he's making a thousand ping-pong balls explode across the stage or lighting bubbles on fire, it'll be a surprise for everyone!