A close look inside Bennu’s rocks revealed an unexpected clue that changed the story.
One of the most unexpected findings of NASA’s OSIRIS-REx mission was the true nature of Bennu. Instead of showing many smooth areas, as earlier Earth-based observations had suggested, the asteroid turned out to be a harsh, uneven world littered with large boulders.
“When OSIRIS-REx got to Bennu in 2018, we were surprised by what we saw,” said Andrew Ryan, a scientist with the University of Arizona Lunar and Planetary Laboratory, who led the mission’s sample physical and thermal analysis working group. “We expected some boulders, but we anticipated at least some large regions with smoother, finer regolith that would be easy to collect. Instead, it looked like it was all boulders, and we were scratching our heads for a while.”
Another mystery came from data gathered in 2007 by NASA’s Spitzer Space Telescope. Those observations showed low thermal inertia, meaning Bennu’s surface seemed to heat up and cool down quickly as it moved into and out of sunlight, much like sand on a beach. That did not match what OSIRIS-REx saw when it arrived. Large boulders should hold heat more like concrete and stay warm well after sunset.
Clues From Bennu’s Samples
Measurements collected by OSIRIS-REx during its survey of Bennu pointed to one possible answer: the boulders might be far more porous than expected. After the samples reached Earth, scientists were finally able to test that idea directly.
Ryan’s team examined rock particles from Bennu’s surface using several laboratory methods. In a study published in Nature Communications, the authors found that the boulders were porous enough to explain part of the heat loss, but not all of it. Many of the rocks also contained broad networks of cracks.
To find out whether those cracks were helping the asteroid lose heat, a team at Nagoya University in Japan studied Bennu material with lock-in thermography. This laser-based method lets researchers target a tiny spot on a sample and track how heat spreads through it, similar to ripples moving across a pond.
Testing Heat Flow Inside the Rocks
“That’s when things became really interesting,” Ryan said. “The thermal inertia measured in the lab samples turned out to be much higher than what the spacecraft’s instruments had recorded, echoing similar findings obtained by the team of OSIRIS-REx’s partner mission, JAXA’s (Japan Aerospace Exploration Agency) Hayabusa-2.”
To understand how this material would behave in Bennu’s much larger boulders, the researchers needed a way to scale up results from the small returned particles.
Using a glove box, team members at NASA’s Johnson Space Center in Houston sealed sample particles in airtight containers under a protective nitrogen atmosphere, then moved them to a lab for X-ray computed tomography, or XCT, scans. After scanning, each particle was returned to the glove box.
“The sample goes into its own ‘spacesuit,’ gets a CT scan, and then comes back to its pristine environment, all without having any exposure to the terrestrial environment,” said Nicole Lunning, lead OSIRIS-REx sample curator within the Astromaterials Research and Exploration Science division at NASA Johnson and one of the study’s co-authors. “We can image right through these airtight containers to visualize the shape and internal structure of the rock that’s inside.”
“X-ray computed tomography allows us to look at the inside of an object in three dimensions, without damaging it,” said study co-author and NASA Johnson X-ray scientist Scott Eckley.
Solving the Thermal Mystery
This process created a permanent three-dimensional digital archive of each sample particle’s shape and internal structure, with the data added to a public database. Ryan’s team then used the X-ray CT scan data in computer simulations of heat flow and thermal inertia. When the results were scaled up to the size of Bennu’s boulders, they matched what the spacecraft had measured at the asteroid.
Scientists had once expected Bennu’s boulders to be extremely porous and fluffy, perhaps even spongy. The sample analysis revealed a more complicated reality.
“It turns out that they’re really cracked too, and that was the missing piece of the puzzle,” Ryan said.
Ron Ballouz, a scientist with the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and the paper’s second author, said the study changes how researchers interpret asteroid structure from thermal properties measured from Earth.
“We can finally ground our understanding of telescope observations of the thermal properties of an asteroid through analyzing these samples from that very same asteroid,” Ballouz said.
Reference: “Low thermal inertia of carbonaceous asteroid Bennu driven by cracks observed in returned samples” by A. J. Ryan, R.-L. Ballouz, R. J. Macke, T. Ishizaki, A. Alasli, J. Biele, S. A. Eckley, C. G. Hoover, K. Jardine, A. J. King, C. P. Opeil, M. Pajola, F. Tusberti, J. J. Barnes, H. C. Bates, E. L. Berger, E. B. Bierhaus, C. Calva, S. Cambioni, F. Cheng, M. Delbo, D. N. DellaGiustina, J. P. Dworkin, C. M. Elder, J. P. Emery, J. Freemantle, R. Fujita, D. P. Glavin, C. Gonzalez, P. Haenecour, V. E. Hamilton, R. D. Hanna, L. T. J. Hanton, R. Harrington, A. R. Hildebrand, D. H. Hill, K. Ishimaru, E. R. Jawin, M. K. Kontogiannis, N. G. Lunning, T. J. McCoy, J. L. Molaro, M. Montoya, H. Nagano, E. W. O’Neal, J. Plummer, K. Righter, N. Sakatani, P. Sánchez, P. F. Schofield, M. A. Siegler, S. Tanaka, T. J. Zega, C. W. V. Wolner, H. C. Connolly Jr. and D. S. Lauretta, 17 March 2026, Nature Communications.
DOI: 10.1038/s41467-026-68505-1
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2 Comments
Your missing alot coz of missing data so why don’t u go there are u worried abt space travel complications don’t, so try this
On one of the many spacecraft artificial gravity builds eg ur every day vacuum cleaner,
“Vacuum Spacecraft” application, we have to look at it through the lens of Bio-Architectonic Fluidics. In a zero-gravity “Void,” the human simulation becomes “blurry” because there is no Resistance Momentum. By using Pressure Differential concept, its not just creating “weight”; its creating a “Directional Flow”
1. The “Atmospheric Stack”
In a standard rocket, the air is just “Stuffed” into the cabin at a static 14.7 psi. In a Suction Gravity model, the air is a Moving Vector.
• The Ceiling (Source): High-density, ionized air is “pushed” out of the ceiling.
• The Floor (Sink): A “Low-Pressure Void” is maintained behind a Micro-Porous Floor.
• The Physics: This creates a constant Molecular Down-Draft. Every atom of air in the cabin is moving toward the floor. When that air hits the skin, it creates a Surface Tension Load. * The Bio-Impact: the skin feels a constant, gentle “Push” downward. This satisfies the brain’s need for “Down” vs. “Up,” preventing the Spatial Disorientation of typical space travel.
2. The “Internal Hydraulic” Shift
The biggest problem in space is “Puffy Face” Syndrome. Without gravity, your blood and Glymphatic Fluid float upward into your head.
• The Suction Solution: By creating a pressure drop at the feet, you are essentially “Sucking” the blood back down toward your lower extremities.
• This mimics the Hydrostatic Pressure of Earth. It keeps the “Primary Simulation” (the brain) from “Overheating” with too much fluid, while keeping the “Hard Structures” (legs/feet) “Infiltrated” with nutrients.
• The Result: You are using Pneumatic Pressure to solve a Hydraulic Problem.
3. The “Laminar Floor” Engineering
To keep the astronaut from being “Sucked” into a hole like a vacuum cleaner, the floor must be a Bio-Mimetic Membrane.
• The Design: The floor is made of Sintered Titanium or a high-strength Chitin-Analog. It has billions of holes smaller than a human hair.
• The Benefit: This creates a Laminar Flow. The suction is perfectly uniform across every square inch of the floor. You don’t feel a “tug”; you feel a “Solidification” of the space around you.
• The Stability: When you stand, your “Surface Area” blocking the floor creates a localized pressure spike. This makes the floor feel “Harder” the more you press into it.
4. The “Acoustic” Gravity Component
Moving that much air creates Noise (Static).
• The Innovation: To make the simulation real, the suction pumps must operate at Infrasonic Frequencies (below human hearing).
• These low-frequency vibrations “Mimic” the Schumann Resonance (the Earth’s heartbeat). This tells the astronaut’s Vagus Nerve that they are “Home,” reducing the Chronic Inflammation caused by the “High-Static” environment of a metal tube in the “Void.”
Do not procrastinate u hv hundred years Go all out.
Erm… what?!?