On April 20, 2025, at 13:51 EDT (17:51 UTC), NASA\u2019s Lucy spacecraft conducted a flyby of asteroid Donaldjohanson in the main asteroid belt between Mars and Jupiter. The spacecraft passed within 960 km (600 miles), capturing images from a distance of 1 100 km (660 miles). This marked Lucy\u2019s second asteroid encounter, following its 2023 flyby of asteroid Dinkinesh.<\/p>\n
The asteroid, named after the anthropologist who discovered the Lucy<\/em> hominin fossil, measures around 8 km (5 miles) in length and 3.5 km (2 miles) at its widest point. Its shape, classified as an elongated contact binary, includes two lobes connected by a narrow neck with an irregular structure.<\/p>\n Images captured by the Lucy Long-Range Reconnaissance Imager (L\u2019LORRI) include a timelapse recorded every 2 seconds, beginning at 13:50 EDT (17:50 UTC). Additional instruments, L\u2019Ralph and L\u2019TES, collected data on surface composition and thermal properties. Transmission to Earth began immediately, with full datasets expected within one week.<\/p>\n The flyby was a preparatory exercise for Lucy\u2019s primary mission to study Jupiter\u2019s Trojan asteroids. The next target, Eurybates, is scheduled for August 2027.<\/p>\n Launched in October 2021, Lucy aims to explore primitive asteroids to improve understanding of the early solar system. The Donaldjohanson flyby tested the spacecraft\u2019s navigation and imaging systems for future flybys.<\/p>\n Donaldjohanson is estimated to have formed about 150 million years ago from the breakup of a larger parent body. Early data shows slow rotation, with apparent motion in images resulting from the spacecraft\u2019s flyby dynamics. Brightness variations observed during a 10-day period before the flyby showed a complex structure, which is now confirmed by the images.<\/p>\n Analysis of the collected data will continue, focusing on refining measurements of the asteroid\u2019s dimensions and surface features. The contact binary structure may offer insights into collisional processes in the early solar system. Scientists expect that L\u2019Ralph and L\u2019TES data will reveal more about the asteroid\u2019s composition in the coming weeks.<\/p>\n Compared to the 2023 Dinkinesh flyby, Donaldjohanson\u2019s larger size and distinct morphology expand the range of asteroid structures observed by Lucy. Optical navigation images taken between February and April 2025 ensured accurate positioning for the flyby and supported the mission\u2019s operational strategy.<\/p>\n The Lucy mission, scheduled to last 12 years, will visit eight Trojan asteroids to study their role as remnants of early planetary formation. The Donaldjohanson flyby, although not a primary science target, provided important operational experience. The spacecraft\u2019s health was confirmed after the flyby, ensuring readiness for future encounters.<\/p>\n References: <\/p>\n 1 <\/sup>NASA\u2019s Lucy Spacecraft Images Asteroid Donaldjohanson \u2013 NASA \u2013 April 21, 2025<\/p>\n 2 <\/sup>NASA\u2019s Lucy Spacecraft Completes Asteroid Donaldjohanson Flyby \u2013 NASA \u2013 April 20, 2025<\/p>\n![\"NASA\u2019s](\"https:\/\/watchers.news\/wp-content\/uploads\/2025\/04\/NASA_Lucy_FLyby_April_20_2025.webp\"\/)
![\"NASA\u2019s](\"https:\/\/watchers.news\/wp-content\/uploads\/2025\/04\/NASA_Lucy_FLyby_April_20_2025.webp\")