What To Know
- Its inclusion in the mission thus represented a unique opportunity to expand Lucy’s scientific objectives and explore a new aspect of our solar system.
- The scientists analyzed Lucy’s images to gather information about Dinkinesh and Selam, as well as to propose a possible explanation for the formation of the binary.
- Meanwhile, the Lucy mission continues its journey to Jupiter’s Trojan asteroids, which will offer the potential for exciting new discoveries in the years to come.
While flying by the asteroid Dinkinesh on November 1, 2023, the Lucy mission made a surprising discovery: a pair of merged moons now named Selam. This unexpected discovery has opened the way for new research to understand how this structure could have formed.
An unexpected discovery
Originally planned to explore asteroids Trojans of JupiterNASA’s Lucy mission underwent a crucial route change in January 2023. Astronomers decided to add the small main-belt asteroid, Dinkinesh (or “Dinky”), as the first destination. This decision was guided by the fact that this object represents a potentially interesting candidate for the study of asteroids and their characteristics. Its inclusion in the mission thus represented a unique opportunity to expand Lucy’s scientific objectives and explore a new aspect of our solar system. In addition, the Lucy mission was designed with flexibility to allow adjustments to its itinerary based on emerging discoveries and opportunities. This versatility therefore allowed researchers to react quickly to new information and make informed decisions to optimize the mission’s scientific objectives. This change in the Lucy mission’s itinerary resulted in an unexpected discovery: the revelation of Selama pair of merged moons around Dinkinesh. Binaries of this type, called contact binaries, are not common in the solar system, which makes this discovery even more intriguing.
A stereo film of Selam during the flyby of NASA’s Lucy spacecraft on November 1, 2023. Composed of two connected lobes, Selam is the first contact binary satellite ever seen. Credits: NASA/GSFC/SwRI/Johns Hopkins APL/NOIRLab/Brian May/Claudia Manzoni
Training mechanism
The scientists analyzed Lucy’s images to gather information about Dinkinesh and Selam, as well as to propose a possible explanation for the formation of the binary. Their findings, published in the journal offer a fascinating insight into the process of creation of small celestial bodies like asteroids. The proposed model suggests that Selam may have formed from pieces of Dinkinesh that coalesced under the effect of solar heat. Specifically, heating Dinkinesh’s surface unevenly would have caused a small push that caused the asteroid to spin faster, causing it to shed chunks of material. This observation expands our understanding of asteroids and their moons and demonstrates the importance of flexibility and adaptability in space exploration. Meanwhile, the Lucy mission continues its journey to Jupiter’s Trojan asteroids, which will offer the potential for exciting new discoveries in the years to come.
