Scientists investigated how the shape of the human body makes hula hooping possible—and what hips and a waist have to do with it. And, the decision for how to proceed with NASA's Mars Sample Return Mission will fall to the incoming administration.What Makes A Hula Hoop Stay Up?Hula hooping might appear to be a simple physical activity. But there’s some complex math and physics at play as the hoop goes around your body, and scientists haven’t had a clear understanding of those hidden forces—until now. A team of mathematicians at New York University recently published research into the science of hula hooping in the Proceedings of the National Academy of Sciences.Flora Lichtman is joined by Olivia Pomerenk, a PhD candidate in mathematics at New York University, and a coauthor of that paper. She talks with Flora about why the motion of hula hooping prevents the hoop from falling down and which body types make for the best hooper.NASA Considers Cheaper, Faster Ways To Retrieve Mars SamplesNASA’s Mars Sample Return mission is an ambitious project that aims to use the Perseverance rover to collect Martian rocks, sand, and even gulps of Martian air. Then, through a complicated handoff between different spacecraft, it would ferry those samples to Earth.A 2023 assessment found that the original plan to retrieve the samples would be much more expensive, and take much longer, than initially expected.This week, NASA announced two options for how to cut costs and bring the samples to Earth by the late 2030s. But the agency did not solidify a plan, leaving it to the next administration to sort out around 18 months from now. Is the project on the rocks?To get up to speed on the mission, Flora Lichtman talks with Dr. Jim Bell, professor of earth and space exploration at Arizona State University, and distinguished visiting scientist at NASA’s Jet Propulsion Laboratory.Transcripts for each segment will be available after the show airs on sciencefriday.com.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.