NASA's Lucy spacecraft has captured stunning images of asteroid Donald Johnson, showing it is a contact binary star with an unusual "ice cream cone" shape. This unexpected geological complexity sheds new light on the early solar system. Although the impact was not the Lucy's primary target, it was on its way to its primary target—Trojan asteroids near Jupiter - Previously, a comprehensive test of Lucy's instruments was conducted.

Asteroid Donald Johnson imaged by the Lucy Long Range Reconnaissance Imager (L'LORRI). This is one of the clearest images ever returned during a flyby of NASA's Lucy probe. The image was taken on April 20, 2025, at 1:51 PM EDT (17:51 UTC), near closest approach, at a distance of approximately 1,100 kilometers (660 miles). The Lucy probe's closest approach was 960 kilometers (600 miles) away, but the image shown here was taken about 40 seconds before closest approach. The image has been sharpened and processed to enhance contrast. Image source: NASA/Goddard Space Flight Center/Southwest Research Institute/Johns Hopkins Applied Physics Laboratory/NOIRLab

During its second flyby of the asteroid, NASA's Lucy spacecraft captured a close-up image of an oddly shaped fragment of an asteroid that is believed to have formed about 150 million years ago. On April 20, 2025, the Lucy spacecraft flew by about 600 miles (960 kilometers) from the asteroid named Donald Johnson and has begun to send back images of the impact.

Previous observations showed the asteroid's brightness changed significantly over a 10-day period, hinting at an irregular shape. Lucy's first images confirmed these speculations by revealing an object resembling an elongated contact binary, formed from the merger of two smaller objects. What surprised the scientists was the shape of the narrow, twisted neck connecting the two lobes, which resembles a pair of stacked ice cream cones.


Image captured by the Lucy Long Range Reconnaissance Imager (L'LORRI) aboard NASA's Lucy spacecraft during a flyby of asteroid Donald Johnson. This time-lapse photography shows that starting at 1:50 PM ET (17:50 UTC) on April 20, 2025, images were taken approximately every 2 seconds. The asteroid spins very slowly; its apparent rotation here is due to the motion of the spacecraft during its flyby at a distance of 1,000 to 660 miles (1,600 to 1,100 kilometers) from Donald Johnson. The spacecraft's closest approach was 600 miles (960 kilometers), but the image shown here was taken about 40 seconds before Donald Johnson's closest approach of 660 miles (1,100 kilometers). Image source: NASA/Goddard Space Flight Center/Southwest Research Institute/Johns Hopkins Applied Physics Laboratory

"The geology of asteroid Donner Johnson is extremely complex," said Hal Levison, principal investigator of the Lucy project at the Southwest Research Institute in Boulder, Colorado. "As we learn more about their complex structures, they will reveal important information about the building blocks and collision processes of the solar system's planets."

Preliminary analysis of images taken by Lucy's L'LORRI camera shows that the asteroid is larger than expected, about 8 kilometers long and about 3.5 kilometers at its widest point. Because the asteroid is too large to fit completely into the camera's field of view, only parts of its structure are visible in the first high-resolution images. The remaining data, which will take about a week to receive, will help scientists create a more complete model of the asteroid's overall shape.

This image shows the moonrise as the satellite rises behind the asteroid Dinkinesh, captured by the Lucy Long Range Reconnaissance Imager (L'LORRI). This is one of the clearest images ever returned by NASA's Lucy spacecraft during its flyby of an asteroid binary. The image was taken on November 1, 2023, at 12:55 pm EDT (16:55 UTC), less than a minute from the asteroid Dinkinesh's closest approach and from a distance of approximately 270 miles (430 kilometers). From this perspective, the moon lies behind the main asteroid. Images are sharpened and processed to enhance contrast. Image source: NASA/Goddard Space Flight Center/Southwest Research Institute/Johns Hopkins Applied Physics Laboratory/NASA

First flyby of asteroid target with LucyDinkinesh(Dinkinesh) Likewise, Donald Johnson was not the primary scientific target of the Lucy mission. While the Dinkinesh flyby was planned to be a systems test of the mission, the encounter was a full dress rehearsal, with the team conducting an intensive series of observations to maximize data collection. Data collected by Lucy's other scientific instruments - the L'Ralph color imager and infrared spectrometer and the L'TES thermal infrared spectrometer - will be retrieved and analyzed in the coming weeks.

NASA's Lucy probe was launched on October 16, 2021, and conducted the first reconnaissance of the Trojan asteroid group. The Trojans are a group of primitive asteroids orbiting alongside Jupiter. In this artistic concept (not to scale), the Lucy probe is flying past the Eurybatus asteroid group, one of six scientifically important Trojan asteroids of varying shapes to be studied.

The Lucy spacecraft will spend much of the remainder of 2025 traveling through the main asteroid belt. Lucy will encounter the mission's first major target, the Jupiter Trojan asteroid Eurybates, in August 2027.

“These early images from Donald Johnson once again demonstrate the power of the Lucy spacecraft as an engine of exploration,” said Lucy mission project scientist Tom Statler of NASA Headquarters in Washington. "When Lucy reaches the Trojan asteroid, it will open a new window into the history of our solar system, and the potential is huge."

Lucy will explore Jupiter's Trojan asteroids - which are considered "fossils of planet formation." Image source: NASA Goddard Space Flight Center

NASA's Lucy mission is a groundbreaking journey to explore the Trojan asteroids. Trojan asteroids are ancient relics of the early solar system that orbit the sun near Jupiter. The mission is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, and involves extensive collaboration across multiple agencies.

Goddard Spaceflight Center is responsible for overall mission management, systems engineering, safety and mission assurance, and developed the L'Ralph instrument that captures visible and infrared data. The mission's principal investigator, Hal Levison, works at the Southwest Research Institute (SwRI) in Boulder, Colorado. Headquartered in San Antonio, Southwest Research Institute leads scientific planning, scientific teams and data processing.

Lockheed Martin Space in Littleton, Colorado, built the Lucy spacecraft, designed its complex orbit and is responsible for flight operations. KinetX Aerospace and Goddard Space Flight Center are jointly responsible for the spacecraft's navigation.

Lucy is equipped with advanced instruments including:

L'LORRI (Lucy Long Range Reconnaissance Imager) was built by the Johns Hopkins Applied Physics Laboratory for detailed imaging.

L'TES (Lucy Thermal Emission Spectrometer) was built at Arizona State University for thermal measurements.

Lucy is the 13th mission in NASA's Discovery program, which is overseen by NASA's Marshall Space Flight Center in Huntsville, Alabama. With this mission, scientists hope to gain new insights into the early history of the solar system.

Compiled from /scitechdaily