A recent study led by the Southwest Research Institute sheds light on the formation of the main belt asteroid (52246) Donaldjohanson. This asteroid is believed to have formed approximately 150 million years ago following the disruption of a larger parent body. The research reveals that both the asteroid's orbit and spin properties have undergone significant evolution since its formation.
Background on Donaldjohanson
The asteroid Donaldjohanson, which has a diameter of about three miles, will be the target of NASA's Lucy spacecraft as it flies by on April 20, 2025. The upcoming encounter is expected to yield valuable data regarding its surface, geological characteristics, and impact cratering history.
"From our ground-based observations, we can see that Donaldjohanson is a distinctive object," stated Dr. Simone Marchi, the study's lead author and deputy principal investigator for the Lucy mission. The paper detailing these findings, titled A Pre-flyby View on the Origin of Asteroid Donaldjohanson, a Target of the NASA Lucy Mission, was published in The Planetary Science Journal.
Formation and Characteristics
The study posits that Donaldjohanson is likely a member of the Erigone collisional family, a group of asteroids sharing a similar orbital path that resulted from the fragmentation of a larger asteroid. This family of asteroids formed in the inner main belt, close to the origins of notable near-Earth asteroids such as (101955) Bennu and (162173) Ryugu, both of which have been recently explored by NASA and JAXA missions, respectively.
"Understanding how Donaldjohanson formed may help us elucidate its unique characteristics," Marchi added. Data suggests that the asteroid may be long and spin slowly, potentially influenced by thermal torques that adversely affect its rotation over millions of years.
Features of the Study
The research included several key findings summarized in the table below:
| Feature | Details | Significance |
|---|---|---|
| Estimation of Age | Approximately 150 million years | Provides insights into the formation timeline of the asteroid |
| Asteroid Characteristics | Peculiar shape and slow rotation | Indicates potential historical influences on its evolution |
| Collisional Family | Member of the Erigone asteroid family | Links to the dynamics of asteroid fragmentations |
| NASA's Lucy Mission | Planned flyby on April 20, 2025 | Expected to provide detailed insights into surface geology |
| Geological Insights | Plausibly contains clays and organic materials | May enhance understanding of the primordial solar system |
Future Directions and Implications
The findings from this study are crucial not only for understanding Donaldjohanson's place in the solar system but also for broader planetary science implications. The Lucy mission, capable of visiting a total of 11 asteroids over a span of 12 years, intends to capitalize on this flyby to conduct engineering tests for navigating to the Trojan asteroids.
Moreover, Lucy will gather data that could act as essential fossils of the planet formation process, providing vital clues about the history of our solar system. According to Dr. Hal Levison, the principal investigator for the Lucy mission, "By studying main belt asteroids, we can perform crucial tests of spacecraft navigation systems in preparation for the main event of studying the Trojans."
Conclusion
As we approach the scheduled flyby, the anticipation surrounding this mission continues to grow. The data obtained can not only redefine our understanding of Donaldjohanson but may also unravel deeper insights into the nature of asteroids and their role in the history and evolution of our solar system.
For More Information
- Phys.org - Asteroid Donaldjohanson Formed 150 Million Years Ago
- The Planetary Science Journal - A Pre-flyby View on the Origin of Asteroid Donaldjohanson
- NASA - Lucy Mission Homepage
Further research and exploration are necessary to fully understand the complexities of asteroids like Donaldjohanson and their contributions to our knowledge of planetary science and history.
