One of the first astronauts to orbit the Moon said on Wednesday that it's "stupid" to plan human missions to Mars.

Bill Anders, who was the lunar module pilot for NASA's Apollo 8 mission, told BBC Radio 5 Live that sending crews to the Red Planet would be "almost ridiculous."

The U.S. space agency's goals include sending humans to Mars for exploration and scientific study.

"What's the imperative? What's pushing us to go to Mars?" Anders, 85, said, adding: "I don't think the public is that interested."

Still, the retired astronaut did explain that he's a big supporter of NASA's unmanned programs to Mars — "mainly because they're much cheaper."

Does he know something the rest of us don't? To read more, click here.