SAN ANTONIO — March 17, 2025 — A groundbreaking study led by the Southwest Research Institute (SwRI) has provided new insights into the formation and evolution of the main belt asteroid (52246) Donaldjohanson. This asteroid, approximately three miles in width, is a fascinating object of study and is scheduled for an encounter with NASA’s Lucy spacecraft on April 20, 2025. The mission will gather critical data that is expected to redefine our understanding of asteroids and their significance in the context of solar system formation.
The research indicates that Donaldjohanson could have formed around 150 million years ago when a larger parent asteroid fragmented. Such events are common in the solar system, where collisions and subsequent breakup lead to the creation of smaller bodies. The study suggests that Donaldjohanson has experienced a significant evolution in its orbit and rotational characteristics since its formation, making it a unique target for the Lucy mission.
Dr. Simone Marchi, deputy principal investigator of the Lucy mission and lead author of this pivotal research published in The Planetary Science Journal, remarked on the unusual characteristics of Donaldjohanson. The analysis indicates that this asteroid might be elongated and a slow rotator, properties that could stem from thermal torques accumulated over millions of years. The slow rotation and peculiar shape of Donaldjohanson pose intriguing questions about its history and the processes that shaped its current state.
Lucy’s goal is to study a type of asteroid that is common in the main belt, typically composed of silicate rocks and potentially containing clays and organic materials. Researchers believe that Donaldjohanson is part of the Erigone collisional asteroid family, created by the fragmentation of a larger body. This family of asteroids is situated in the inner main belt and is thought to share an origin with the near-Earth asteroids (101955) Bennu and (162173) Ryugu, both of which have been previously explored by NASA’s OSIRIS-REx and JAXA’s Hayabusa2 missions.
The upcoming flyby of Donaldjohanson is highly anticipated, as preliminary observations suggest distinct physical traits that distinguish it from both Bennu and Ryugu. Dr. Marchi expressed excitement about the potential for unexpected discoveries during the flyby, which could reveal unknown connections between these celestial bodies. As researchers prepare for the encounter, they are eager to analyze data that might clarify the formation processes and evolutionary pathways of this intriguing asteroid.
The name Donaldjohanson pays homage to the anthropologist who discovered Lucy, the famous fossilized skeleton of an early hominin found in Ethiopia in 1974. This nomenclature links the asteroid to the contributions of its namesake to our understanding of human evolution. Just as the Lucy fossil shed light on the origins of humanity, the Lucy mission is poised to revolutionize our knowledge concerning the early solar system and the formation of Earth.
Dr. Hal Levison, principal investigator of the Lucy mission at SwRI, noted the ambitious nature of the project. The spacecraft is designed to visit a total of 11 asteroids over its 12-year mission, focusing on the Trojan asteroids that inhabit two swarms in front of and behind Jupiter. This ambitious itinerary not only allows scientists to conduct close-up studies of the asteroids but also provides invaluable engineering opportunities to test the spacecraft’s navigation systems prior to the pivotal encounters with the Trojan asteroids.
Lucy’s mission management is led by NASA’s Goddard Space Flight Center located in Greenbelt, Maryland, while Lockheed Martin Space in Littleton, Colorado, built the spacecraft itself. As part of NASA’s Discovery Program, Lucy exemplifies the agency’s commitment to exploring the solar system and enhancing our understanding of planetary formation processes.
The research team anticipates that the encounter with Donaldjohanson will yield rich scientific data that could shed light on the conditions under which the early solar system formed. These insights are critical as they will help scientists decipher the complex history of our solar neighborhood and understand how different types of asteroids have evolved over the eons.
As scientists prepare for this exciting flyby, the broader implications of the Lucy mission continue to resonate within the global scientific community. The mission represents a unique opportunity to bridge the past and the present, connecting discoveries of the origins of life on Earth to the celestial bodies that orbit the sun.
The Lucy mission, with its ambitious schedule and groundbreaking objectives, underscores the importance of continued exploration as we strive to unearth the mysteries of our cosmic heritage. The anticipated data from Donaldjohanson has the potential to reshape knowledge not only about asteroids but also about the foundational processes that led to the emergence of the Earth and other terrestrial planets.
The excitement surrounding the upcoming flyby of Donaldjohanson exemplifies the deep human quest for knowledge—a quest that links our understanding of the cosmos with our own existence on this planet. As the Lucy spacecraft prepares for its historic rendezvous, we can look forward to a wealth of new information that may illuminate the origins not only of asteroids but also of our own origins in the grand context of the universe.
Subject of Research: Donaldjohanson and asteroid formation
Article Title: Insights into the Asteroid Donaldjohanson: Formation, Evolution, and the Lucy Mission
News Publication Date: March 17, 2025
Web References: https://www.swri.org/markets/earth-space/space-research-technology/space-science/planetary-science
References: Marchi, S., et al., “A pre-flyby view on the origin of asteroid Donaldjohanson, a target of the NASA Lucy mission,” The Planetary Science Journal, DOI: 10.3847/PSJ/adb4f4
Image Credits: Credit: SwRI/ESA/OSIRIS/NASA/Goddard/Johns Hopkins APL/NOIRLab/University of Arizona/JAXA/University of Tokyo & Collaborators
Keywords
asteroid, Donaldjohanson, Lucy mission, asteroid formation, NASA, solar system, spacecraft, celestial bodies, research, planetary science, Trojans, SwRI, space exploration.
