NASA’s Lucy Reveals Wobbling, Peanut-Shaped Asteroid
Even small asteroids lead complex lives. During its flyby of the asteroid Donaldjohanson last year, NASA’s Lucy spacecraft revealed the asteroid to be a wobbly, peanut-shaped body that has undergone a
Even small asteroids lead complex lives. During its flyby of the asteroid Donaldjohanson last year, NASA’s Lucy spacecraft revealed the asteroid to be
Read Full Story at NASA →Why This Matters
The revelation that asteroid Donaldjohanson is wobbling and peanut-shaped challenges long-held assumptions about the structural stability of small celestial bodies. This discovery suggests that even modest asteroids can experience dynamic rotational forces capable of reshaping their forms over time, offering critical insights into the early solar system’s chaotic formation era. It also underscores the importance of targeted flyby missions in uncovering the hidden complexities of near-Earth objects.
Background Context
Launched in 2021 as part of NASA’s Discovery Program, the Lucy spacecraft is the first mission dedicated to exploring the Trojan asteroids—primitive bodies sharing Jupiter’s orbit. While Lucy’s primary targets are these distant Trojans, its 2023 flyby of Donaldjohanson, a main-belt asteroid named after paleoanthropologist Donald Johanson, provided an unexpected bonus. The mission’s detour into the inner asteroid belt highlights the strategic flexibility of modern planetary science.
What Happens Next
Scientists will now analyze Lucy’s data to model how Donaldjohanson’s wobble and irregular shape influence its trajectory and potential interaction with other bodies. This could refine collision risk assessments for similarly shaped near-Earth objects. Meanwhile, the mission team will prepare for Lucy’s 2027 arrival at the Trojan asteroids, where similar surprises may await. Expect revisions to asteroid formation theories as new flyby data accumulates.
Bigger Picture
The discovery aligns with a growing recognition that small asteroids are far from static relics; they are active, evolving worlds shaped by spin, impacts, and gravitational forces. As missions like Lucy and Japan’s Hayabusa2 continue to reveal structural oddities among asteroids, the line between comets and asteroids blurs further. This trend is reshaping planetary defense strategies and our understanding of how planetary building blocks migrated in the early solar system.
