NASA explains why Bennu's boulders lose heat so fast

OSIRIS-REx scientists found that Bennu's boulders shed heat quickly because of high porosity and dense networks of internal cracks. X-ray CT scans of returned samples and heat-transfer simulations reproduced the low thermal inertia measured by the spacecraft.

• Porosity and internal cracks explain Bennu's rapid heat loss
• Samples were XCT-scanned in sealed containers without exposure to Earth
• Simulations scaled from particles to boulders matched spacecraft data
• Findings were published in Nature Communications