NASA’s Lucy spacecraft has captured its first images of the main belt asteroid Donaldjohanson, a crucial step as the mission gears up to explore the Trojan asteroids near Jupiter. While not a Trojan itself, Donaldjohanson’s location offers a convenient flyby opportunity for Lucy before it journeys to its primary targets.
This small asteroid, named after the discoverer of the famous fossilized hominid “Lucy,” measures approximately 3 miles (4 kilometers) in diameter. The recently released images from NASA, captured by Lucy’s LOng Range Reconnaissance Imager (L’LORRI), depict Donaldjohanson as a faint point of light from a distance of 45 million miles (70 million kilometers).
Lucy’s Upcoming Encounter with Donaldjohanson
A close encounter with Donaldjohanson is scheduled for April 20, 2025, during which Lucy will pass within 596 miles (960 kilometers) of the asteroid. This flyby serves as a critical test and calibration opportunity for the spacecraft’s instruments before its main mission begins.
Launched in October 2021, Lucy has already observed asteroid Dinkinesh and its small moon. A crucial Earth gravity assist late last year boosted Lucy’s speed relative to the Sun by over 16,000 miles per hour (25,750 kilometers per hour), propelling it towards its next target.
The Significance of Donaldjohanson
Although a preliminary target, Donaldjohanson holds scientific interest. Believed to be a fragment from a massive asteroid collision roughly 130 million years ago, this space rock offers insights into the formation of the Erigone family of asteroids.
Over the next two months, Lucy will continue imaging Donaldjohanson as part of its optical navigation program. These observations will become increasingly clearer as the spacecraft approaches the asteroid, culminating in the close flyby on April 20.
Lucy’s Journey to the Trojan Asteroids
Following the Donaldjohanson encounter, Lucy will set its sights on its primary mission: the Trojan asteroids. The first Trojan target, Eurybates, a much larger asteroid spanning approximately 40 miles (64 kilometers), awaits Lucy’s arrival on August 12, 2027.
This flyby will be crucial for understanding the composition and origins of the Trojan asteroids, a group of space rocks sharing Jupiter’s orbit around the sun. Lucy will also observe Eurybates’ small satellite, Queta, during this encounter.
Exploring the Trojan Swarm
Lucy’s mission will continue with a series of flybys of various Trojan asteroids, providing a unique opportunity to study these ancient remnants of the early solar system. The final scheduled flyby, targeting the binary asteroid system Patroclus and Menoetius, is set for 2033. Even after completing its planned flybys, Lucy will remain in a stable orbit, continuing its journey through the Trojan asteroid swarm for years to come.
