March 07, 2025

TWiS 151: In Search of Alien Megastructures - With Former NASA Chief Scientist, Dr. Jim Green

1 hour 16 minutes

In this episode of This Week in Space, Rod Pyle and Tariq Malik talk with Dr. Jim Green, former NASA Chief Scientist. He discusses how we can search for technosignatures that might indicate advanced civilizations in other star systems, new ideas on Mars sample return, and his fascinating experience consulting on the movie, The Martian! Also: this week's robotic landings on the Moon - one successful, one partly so; what's up with the USAF X-37B mini-shuttle; and recent news on those Energizer Bunnies of space, Voyagers 1&2. Their wings have been clipped a bit, but they just keep going... join us!

News

Lunar Landing Week: Firefly Aerospace's Blue Ghost lander achieved a flawless touchdown in Mare Chrisium, the Intuitive Machines Athena lander reached the Moon's south polar region but experienced issues with its navigation radar (and tipped over), and SpaceX's Starship test flight 8 successfully caught its booster for the third time but lost control of the upper stage, resulting in the breakup of the upper stage and debris over the Bahamas and Caribbean.

NASA powered down additional instruments on both Voyager 1 and Voyager 2 to extend their remaining power supply, including Voyager 1's cosmic ray system that helped confirm its entry into interstellar space in 2012.

The secretive US Space Force X-37B space plane landed at Vandenberg Space Force Base after 434 days in orbit, completing its seventh mission, which tested new orbital capabilities, including aerobraking techniques.

A newly released list showcases the world's top ten locations for dark skies and stargazing, with the US only having only one location—in Hawaii—to make the list.

Dr. Jim Green

His Career: Dr. Green goes over his former role as NASA's Chief Scientist and highlights key aspects of his career, including running the National Space Science Data Center (NSSDC) and leading NASA's Planetary Science Division, and how his interest in space first began.

The Martian: Dr. Green also explains how he got involved as a consultant for Ridley Scott's movie, "The Martian," and how NASA got really involved with the film. He also shares his favorite scene from the movie.

NASA's Search for Alien Civilizations: Dr. Green shares how he helped shift NASA's focus from traditional SETI to searching for technosignatures like Dyson Spheres and O'Neill structures in other star systems, securing $10 million in funding for research that could detect megastructures in our astronomical data while noting that humanity may need similar space habitats in 800 million years when the sun makes Earth uninhabitable.

Mars Sample Return Strategy: Dr. Green explains how NASA's evolving plan to return samples fropm Mars includes developing Mars Ascent Vehicles that could eventually support human missions while revealing that Perseverance was deliberately designed to place sample tubes on the surface so any nation could retrieve them, making the mission more politically viable with budget offices and Congress.

Humanity's Cosmic Future: Dr. Green reveals that he helped create NASA's Commercial Lunar Payload Services (CLPS) program to support new companies for lunar missions. Despite early failures, he emphasized that humanity must utilize space resources and capabilities to

These show notes have been truncated due to length. For the full show notes, visit https://twit.tv/shows/this-week-in-space/episodes/151

Hosts: Rod Pyle and Tariq Malik

Guest: Dr. Jim Green

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By TWiT

4.6

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