Left: Buzz Aldrin on the moon. Right: An artist's rendition of humans on Mars. (Photos courtesy of NASA.)

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Forty years ago today, July 16th, 1969, mankind blasted off for the Moon, on its way to “The Eagle has landed” and “one small step.” Ticker tape parades and the American flag planted proudly on the lunar surface.

Forty years later, we have problems closer to home. But space still beckons. The US has competitors on the high frontier. And American space enthusiasts are debating where the next big push should be. Back to the Moon – maybe to build a giant solar energy station? Or straight on to Mars – maybe to create a second Earth.

This hour, On Point: Moon versus Mars, and what comes next in space.

You can join the conversation. Tell us what you think — here on this page, on Twitter, and on Facebook.

-Tom Ashbrook

Guests:

Robert Zubrin is president of Pioneer Astronautics, an aerospace research and design company. He previously worked as an engineer at Lockheed Martin. He is the author of “The Case for Mars: The Plan to Settle the Red Planet and Why We Must” and “How to Live on Mars: A Trusty Guidebook to Surviving and Thriving on the Red Planet.”

David Kring is Senior Staff Scientist at Universities Space Research Association’s Lunar and Planetary Institute in Houston, TX. He is the former director of the NASA Space Imagery Center at the University of Arizona.

Harrison Schmitt is a crewmember from the 1975 Apollo 17 lunar mission, and a former New Mexico Senator.

Refurbished photo of Neil Armstrong and Buzz Aldrin planting the U.S. flag on the Moon. (NASA)

Listen to NPR’s report on the missing Apollo 11 tapes and watch restored videos of Neil Armstrong and Buzz Aldrin walking on the moon and planting the U.S. flag.

Robotic Mars exploration has been no picnic. Half of all Mars missions have ended in failure. But right now, the Mars Phoenix Lander is up there, well-landed, sending back astonishing images, and — it appears — shaking off its problems extending the eight-foot arm that will dig for ice.

The Phoenix is looking for conditions that would support life on Mars. But the bigger search for life “out there” goes way beyond the Martian north pole, to “weird life” and “exoplanets.”

This hour, On Point: The Phoenix has landed: the new mission to Mars, and the search for life beyond Earth.

-Tom Ashbrook

Guests:

Peter Smith, principal investigator and project leader of the Phoenix Mars Mission and a scientist at the University of Arizona’s Lunar and Planetary Laboratory.

Sara Seager, professor of planetary science and associate professor of physics at MIT.

Michael Meyer, lead scientist for NASA’s Mars Exploration Program.