NASA's Lucy Traces 5-Mile Asteroid to 155-Million-Year-Old Collision
Updated
Updated · Gizmodo · Jun 18
NASA's Lucy Traces 5-Mile Asteroid to 155-Million-Year-Old Collision
3 articles · Updated · Gizmodo · Jun 18
Summary
Lucy flyby data show asteroid Donaldjohanson is likely a fragment of a larger body shattered 155 million years ago, according to a Science study published Thursday.
600 miles from the asteroid, the spacecraft captured close-up images of a peanut-shaped object about 5 miles long whose two cratered lobes appear to have reaccumulated after the breakup.
Researchers linked Donaldjohanson to the water-rich Erigone family of nearly 1,800 asteroids, whose roughly 50-mile parent body was struck by a 12-mile impactor.
Surface clues also point to later upheaval: craters smaller than 0.2 miles seem erased, suggesting a more recent impact caused seismic shaking, while iron-bearing phyllosilicates indicate past liquid water alteration.
The findings sharpen scientists' picture of how near-Earth asteroids evolve as Lucy heads toward its main Trojan asteroid tour, set to begin in 2027.
What lessons from the 2025 flyby will shape Lucy's historic 2027 encounter with the Trojan asteroids?
How does Donaldjohanson's fragmented origin story change our strategy for deflecting potentially hazardous asteroids?
What does this ancient, water-bearing asteroid reveal about how Earth's own oceans may have formed?
Lucy’s 2025 Donaldjohanson Flyby: A Pivotal Step Toward Unlocking Jupiter Trojan Asteroid Secrets
Overview
On April 20, 2025, NASA's Lucy spacecraft completed a close flyby of the asteroid Donaldjohanson, marking a major milestone in its mission to explore Jupiter's Trojan asteroids. These Trojans, held in stable orbits near Jupiter, are considered invaluable remnants from the early solar system and offer a unique window into its formative years. The data collected during the Donaldjohanson flyby is expected to provide crucial scientific insights, helping scientists better understand both the evolutionary processes of near-Earth asteroids and the broader formation and evolution of the entire solar system.