NASA’s Lucy spacecraft captured the most detailed images yet of an oddly shaped asteroid during its recent flyby, revealing the space object’s weird features and “strikingly complex” attributes.
Lucy’s visit to the peculiar asteroid, dubbed Donaldjohanson, marked the intrepid NASA probe’s second close encounter, showcasing the object’s unusual barbell shape and offering images that provide additional clues to its unique geology.
The flyby occurred on April 20, 2025, as Lucy approached to within just 600 miles of Donaldjohanson. High-resolution images of the contact binary object, which possesses two outer lobes joined by a narrow “neck,” offered a look at Lucy’s capabilities ahead of its mission focus, which involve reconnaissance of Jupiter’s Trojan asteroids.
Even though Lucy’s quick visit with Donaldjohanson was only a short stop along the way toward its intended mission, the data it collected offers significant new data about planetary building blocks that formed over 150 million years ago.
A Weirdly Shaped Asteroid
Preliminary imagery dispatched to Earth from Lucy’s Long-Range Reconnaissance Imager (L’LORRI) revealed an elongated, contact binary asteroid resembling what some scientists have likened to a barbell or a pair of ice cream cones joined at the tips. One of the asteroid’s lobes is noticeably smaller than the other, although both possess similar circumferences.
Craters are visible along the asteroid’s surface as well, with the larger lobe displaying the greatest number of impact marks. Overall, the asteroid’s entire surface is covered in a smooth terrain with a light gray coloration.
Imagery of the recent encounter appears to show the object rotating slightly, although this is an illusion resulting mostly from Lucy’s motion as it passed. The spacecraft’s movement caused the asteroid’s slow spin to appear as though it is rapidly turning in the new NASA imagery.
“These early images of Donaldjohanson are again showing the tremendous capabilities of the Lucy spacecraft as an engine of discovery,” said Tom Statler, Lucy program scientist at NASA Headquarters in Washington.
Lucy’s encounter with Donaldjohanson follows the earlier test flyby of asteroid Dinkinesh, which allowed the NASA mission team to validate the spacecraft’s systems. With its flyby of Donaldjohanson, the team was able to execute more dense observational campaigns, allowing them to fine-tune data collection strategies.
Donaldjohanson isn’t the first strangely-shaped asteroid NASA’s spacecraft have encountered. Kuiper Belt Object 486958, otherwise known as Arrokoth, also possesses an unusual double-lobed shape that bears a passing similarity to the new images of Donaldjohanson.
Donaldjohanson Reveals Its Secrets
Based on the Lucy team’s initial analysis of the data collected during the recent flyby, Donaldjohanson is significantly larger than previous estimates yielded, clocking in at about 5 miles long and 2 miles wide. This makes it large enough that the entire asteroid was unable to fit within L’LORRI’s field of view during Lucy’s closest approach.
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Along with imagery, instrument readings collected during the visit provided thermal and infrared data, which is currently undergoing downlinking and processing.
“Asteroid Donaldjohanson has strikingly complicated geology,” said Hal Levison, Lucy’s principal investigator at the Southwest Research Institute in Boulder, Colorado. “As we study the complex structures in detail, they will reveal important information about the building blocks and collisional processes that formed the planets in our solar system.”
Trojans on the Horizon
Lucy’s mission is just beginning, and following its visit with Donaldjohanson, it will now proceed through the main asteroid belt, making its first scheduled encounter with a Trojan asteroid called Eurybates in August 2027.
Orbiting the Sun at the same distance as Jupiter, trojan asteroids are believed to hold preserved remnants from the early solar system. As Lucy’s mission continues, the imagery it provides of these enigmatic space objects will help to expand our understanding of the ancient solar system, as well as the complex geology that makes up its ancient drifting asteroid constituents.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email atmicah@thedebrief.org. Follow his work atmicahhanks.comand on X:@MicahHanks.
