Secrets of Asteroid Bennu with Harold Connolly Jr.

In this episode of StarTalk Radio, Neil deGrasse Tyson and Chuck Nice welcome Harold Connolly Jr., a leading geologist and co-investigator on NASA's OSIRIS-REx mission, to explore the secrets of asteroid Bennu. The conversation dives into how Bennu—a carbonaceous chondrite asteroid—serves as a time capsule from the early solar system, preserving pristine organic compounds, water-bearing minerals, and volatile materials that may have seeded life on Earth. Connolly explains the challenges and triumphs of the OSIRIS-REx mission, including the unexpected discovery of boulders on Bennu’s surface and the successful retrieval of 122 grams of sample material despite technical setbacks. The episode highlights how analyzing these samples has revealed key prebiotic ingredients like amino acids (including tryptophan), phosphorus-rich minerals, and evaporite compounds, all formed in ancient aqueous environments. The discussion also touches on the broader implications for astrobiology, planetary defense, and the role of international collaboration in space science. Connolly reflects on how geologists, astronomers, and biologists must work together to understand life’s origins, emphasizing that the universe doesn’t respect human academic boundaries. Key takeaways include: Bennu’s sample provides the most pristine look at early solar system chemistry; organic compounds on asteroids likely formed through geologic processes, not necessarily life; the discovery of prebiotic molecules like amino acids and sugars in asteroid material supports the idea that Earth’s building blocks may have come from space; international cooperation—between NASA, JAXA, and global scientists—is essential for advancing planetary science; and while Bennu poses a small risk of impacting Earth in 2182, the real value lies in the scientific knowledge gained. The episode underscores that the search for life’s origins is not just about finding life, but understanding the geologic and chemical pathways that made it possible.