Asteroids

What It Covers

Asteroids reveal solar system formation through composition gradients, missions return samples from carbon-rich bodies, DART successfully deflects asteroid moon, surveys track near-Earth objects, future mining potential exists despite legal uncertainties.

Key Questions Answered

• •Asteroid threat assessment: Objects above 120 meters diameter will reach Earth's surface and create craters. One kilometer asteroids cause global consequences with 25% mortality within one year through stratospheric debris disrupting food chains. All such objects tracked for next century.
• •Sample return discoveries: OSIRIS-REx touched Bennu's surface and sank through, revealing rubble pile structure held weakly together. Material contains 10% water in clay minerals plus carbonate and phosphate indicating past liquid water, despite asteroid being only 500 meters across.
• •Planetary defense validation: DART mission successfully altered 160-meter asteroid moon's orbit by direct impact at high velocity. Hera follow-up launches October 2024 to measure exact changes over six months, establishing deflection technology for future threats requiring intervention.
• •Compositional gradient mapping: Inner asteroid belt near Mars contains stony material while outer belt near Jupiter shows progressive carbon enrichment and darker composition. This gradient reveals primordial solar system structure where sun's heat drove away lighter elements closer in.