Jim Bridenstine -- the head of NASA -- says Steph Curry just HAS to be joking about his moon landing theory ... telling TMZ Sports, "I can't imagine he really believes that!!"
The Warriors superstar sent space nerds into a frenzy Monday when he declared on The Ringer's "Winging It" podcast that the moon landing in 1969 never happened.
Enter Bridenstine ... who says Curry's claim is so outrageous -- the point guard just cannot be serious.
"I think it's funny," Jim tells us ... "I can't imagine he really believes that. It's outside the realm of what's possible."
In fact ... Jim REALLY set Steph straight, saying, "Here's the thing, we didn't just go to the moon once, we went to the moon six times! And, we did it from 1969 to 1972!!!"
Bridenstine also doubled down on NASA's invitation to have Curry come check out all their evidence -- saying he'd LOVE to prove Steph wrong and get him involved in the space program afterward!
"My son is a HUGE fan of Steph Curry. So, if we can get him involved in space, I'm for it!"