StarTalk Radio — "Secrets of Asteroid Bennu" with Harold Connolly Jr.

Host: Neil deGrasse Tyson
Co-host: Chuck Nice
Guest: Dr. Harold Connolly Jr. (Founding Chair & Professor, Rowan University; Mission Sample Scientist, OSIRIS-REx)
Date: April 14, 2026

Episode Overview

In this richly engaging episode, Neil deGrasse Tyson and Chuck Nice dive deep into the essence and mysteries of Asteroid Bennu, joined by planetary geologist Dr. Harold Connolly Jr. The trio explores Bennu’s role as a "time capsule" for the early solar system, highlights the incredible scientific journey of NASA's OSIRIS-REx mission, and unpacks how asteroid samples may illuminate origins of life in the universe. The conversation stitches together geologic, chemical, and biological insights with humor, science, and a dash of existential concern about possible future impacts with Earth.

Main Themes

• Why sample asteroids like Bennu?
• The story of the OSIRIS-REx mission & sample return
• Analysis breakthroughs: organic compounds, volatiles, and salts
• What pristine samples tell us about the building blocks of life
• The complex interplay between geology, biology, astronomy, and planetary defense

Key Discussion Points & Insights

1. Why Go to Bennu?

• Motivation for Asteroid Sampling
  Instead of relying solely on meteorites found on Earth (often contaminated), scientists wanted pristine samples:

  “Meteorites as they fall to Earth are contaminated incredibly quickly... So the idea [was] to bring back a sample of pristine material, keep it in a nitrogen environment and analyze it.” — Harold Connolly Jr. (09:08)

• Bennu as a Target
  Chosen because it’s a carbonaceous asteroid (rich in potential life ingredients) and accessible due to its near-Earth orbit:

  “100%. Our scientific goals were to get to an asteroid...that was carbonaceous because we needed to look for what we already know is contained with the asteroids—volatiles, organics, etc.” — Connolly (12:25)

2. OSIRIS-REx Mission: Touch-and-Go Engineering (14:03)

• OSIRIS-REx was a “touch and go” sample mission. The probe essentially “punched” Bennu’s surface, collected regolith, and sent a return capsule back to Earth, landing precisely in the Utah desert.
• The unpredictably loose, “rubble pile” structure of Bennu surprised scientists:

  “We got there, we screamed because there were boulders 11 stories high...It wasn’t quite what we expected.” — Connolly (19:52)

• Ended up retrieving 122 grams of sample—double the minimum needed for major science goals (18:46).

3. Science from the Sample: What’s Inside? (23:30 – 32:24)

• Initial Handling: Ultra-clean nitrogen gloveboxes to minimize contamination.

• Analysis Techniques: Visual, optical, and electron microscopes; chemical dissolution for organics; always with attention to original geologic context.

• Salts & Evaporite Minerals
  Discovery of salt (including table salt analogs), signifying past liquid water and possible prebiotic conditions:

  "A classic example, table salt. Table salt is in the rocks from Bennu, it’s in the rocks from Ryugu." — Connolly (26:54)

• Amino Acids & Organic Molecules
  Found 14–15 amino acids (the building blocks of life) in pristine samples:

  “The main headline is 14 of the 20 amino acids that are needed for life.” — Connolly (31:26)
  “The 15th one was tryptophan...the same stuff you get in turkeys that makes you sleepy.” (32:21)

• Presolar Grains
  Identified “pre-solar” grains (older than the Solar System itself, like nanodiamonds and carbides), giving insight into material predating Sun and planets (46:15–48:52).

4. The Bigger Picture: How Earth Got Its Ingredients (58:03 – 64:32)

• Lithopanspermia Debate
  How meteorites and asteroids may have "seeded" Earth (and Mars) with prebiotic compounds:

  “The asteroids themselves could be seeding Mars and Earth with the prebiotic compounds that are needed for life to evolve.” — Connolly (58:03)

• Discussion on whether ingredients for life are easily formed from “geologic processes” everywhere or if they needed special delivery.

• Meteorite Contamination
  Importance of pristine (non-Earth-contaminated) samples for origin-of-life research:

  “Meteorites are definitely contaminated. So we’re learning a lot about organic chemistry in the Solar System from the asteroid samples that the meteorites are definitely contaminated.” — Connolly (57:06)

5. Bennu’s Impact Threat (67:10–69:49)

• Clarifies “1 in 2700” chance of impact in 2182—plenty of time for mitigation:

  “Given our orbital uncertainties, there’s a chance it could hit Earth in 2182...We want to keep an eye on these.” — Tyson (67:40)

6. Science as Collaboration; The New Golden Era (71:11–73:36)

• Dr. Connolly reflects on the convergence of geology, biology, and astronomy:

  “The universe doesn’t care about how we divide our sciences. The universe is just the universe.” — Tyson (72:06) “Because of these sample return missions...we’re at an exciting time. Understanding how planets form, the baseline geology, the physics, working with astronomers, remote sensors, and biologists to put our hypotheses together in a big-picture scope.” — Connolly (71:11)

• Global science: NASA archives & distributes samples, international collaboration, cross-verification of research.

Notable Quotes & Memorable Moments

• On meteorite contamination:
  “Imagine, you’re sitting around for 4.5 billion years...nothing to do, nobody to bother you, except occasional collision and the Sun hitting you. Then you land on Earth, and within a day you’re contaminated.” — Connolly (08:49)
• On Bennu’s structure:
  “We got there, we screamed...there were boulders 11 stories high.” — Connolly (19:52)
• On OSIRIS-REx’s sampling surprise:
  “We went in 48 centimeters...almost down into the surface. Which we did not really expect.” (21:11)
• On amino acid detection:
  “The 15th one was tryptophan...the same stuff that’s in turkey that makes you sleepy.” — Connolly (32:21), with Chuck quipping, “That’s why Bennu rotates so slowly.”
• On panspermia and planetary defense:
  “If you can make amino acids on rocks in space...you can make amino acids on Earth without the rock.” — Tyson (62:37)
• On collaboration:
  “The universe doesn’t care about how we have divided our sciences...” — Tyson (72:06)

Important Timestamps

| Timestamp | Topic | |---------------|-----------| | 01:56 | Ingredients for life in the universe, asteroids as time capsules | | 03:51 | OSIRIS-REx acronym, mission introduction | | 05:03 | Why sample asteroids? Contamination issues | | 08:49 | Meteorite contamination on Earth | | 12:25 | Why Bennu was selected—accessibility & composition | | 19:52 | Bennu's "rubble pile," sampling challenges | | 22:19 | Touch-and-go collection, unexpected regolith properties | | 23:51 | Lab protocols for sample analysis | | 26:21 | Salt/evaporites as evidence for ancient water | | 31:26 | Discovery of amino acids in Bennu’s sample | | 46:15 | Pre-solar grains—what they are and why they matter | | 58:03 | Lithopanspermia and Earth's early ingredients | | 67:10 | Bennu’s orbital hazard; probability of Earth impact | | 71:11 | Reflections on multidisciplinary collaboration in science |

Science, Humor & Final Thoughts

• Chuck Nice’s comedic interjections kept the tone light even as they discussed “the coolest game of billiards ever” (planet formation) (42:34), and the nonchalance about an asteroid possibly hitting Earth long after any of them are around (67:36).
• Harold Connolly’s deep knowledge of planetary geology, coupled with thoughtful humility (“I’m not a biologist, so keep that in mind” (45:05)), made even complex ideas accessible.
• Neil deGrasse Tyson tied together threads from chemistry, biology, and planetary science, consistently pressing for answers that connect cosmic to everyday scale.

Further Resources

• Follow-up:
  Dr. Harold Connolly Jr’s website for news and publications: haroldconnelly.wordpress.com (75:22)
• Sample Request and Science:
  Researchers can apply to NASA/Johnson Space Center for sample access after the exclusive period. International sharing with JAXA sample teams.
• Stay Current:
  NASA’s official OSIRIS-REx mission pages and Dr. Connolly’s website.

Concluding Message

This episode revels in science’s collaborative spirit, the thrill of discovery in asteroid Bennu’s ancient powder, and the persistent humility (and humor) required when asking profound questions about life's origins and Earth's cosmic vulnerability—all of it summed up in StarTalk’s signature style:

“Keep looking up.” — Neil deGrasse Tyson

End of summary.