The only geologist ever to ply his science in person on an extraterrestrial body views the current exploration of Mars from a special perspective.
"What these young men and women have achieved is quite remarkable. Those Mars Exploration Rovers are no substitute for a human being on the spot," said Harrison Schmitt, head of AAPG's Astrogeology Committee.
Schmitt was the last man to step onto the moon, traveling aboard Apollo 17 in 1972.
The performance of the rovers beyond their expected life and the dedication of the engineers and scientists behind the mission "are just what we saw all through Apollo," he said.
Humans come equipped with "a fully reprogrammable computer" completely integrated with complex visualization and manipulative tools -- their brain, eyes and hands," Schmitt said.
"I think we have to look way into the future to see robots duplicate this," he added.
Schmitt hopes the current series of remote exploration missions will help spur interest in putting humans back on the moon and into space.
The Mars rovers may take days to reach an outcrop that scientists want to study, and the data they gather from spectrometry and visual analysis may leave questions unanswered.
"Those questions could have been answered quickly by an exploration geologist -- and new questions asked," he said.
"For efficiency and completeness, you need humans," he added. "There is an extra price to pay to get them there, but they give you more in value.
"It's hard to imagine an exploration program here (on earth) solely with robotics," he continued. "It's not cost-effective, not complete. Remote sensing is important, but robotics is not in a position to do it all."
Schmitt says he and others wants to see humans return to the moon and deep space.
"We think the private sector should lead the way," he said. "It's not yet clear what kind of corporation can attract and sustain investor interest.
"I think it should be paid for with investor capital rather than taxes," he said.
But once that matter is resolved ...
"With a believable and sustainable commitment, we could be back on the moon in 10 years and on Mars in 15 to 20 years," Schmitt said.
Schmitt thinks the commercial potential of space eventually will become apparent.
The moon is a potential energy resource target. The only viable resource identified there so far is Lunar Helium 3, he said. The substance was found in moon samples in 1969 and '70, but not identified as a potential energy source for fusion technology until about 1985, Schmitt said.
He believes Mars might yield similar potential -- and beyond the economic potential, he said, the value to science remains a powerful lure.
"The moon has given us clues to the origin of the moon, earth and solar system," he said, "that I suspect we would not have gotten any other way."