CAPE CANAVERAL, Fla.—NASA’s Lucy spacecraft is on course to pass by a minor asteroid this weekend, on its mission towards a much larger target: the uncharted asteroid clusters near Jupiter. This marks the spacecraft’s second asteroid encounter since its 2021 launch, embarking on a journey that encompasses 11 celestial bodies. These close flybys are crucial for scientists striving to gain insights into our primordial solar system, which was marked by planet formation, while asteroids are considered ancient relics of that era.
Lucy will approach its inaugural Trojan asteroid near Jupiter in 2027, making the forthcoming flyby a mere practice run. On Sunday, the spacecraft will activate its suite of three science instruments to scrutinize an asteroid called Donaldjohanson. The asteroid is situated 139 million miles (223 million kilometers) from Earth within the asteroid belt located between Mars and Jupiter. Given this distance, it will take a full 12 minutes for data to reach the mission control team in Colorado.
Interestingly, the asteroid’s namesake, a paleontologist, plans to witness this celestial event firsthand at Lockheed Martin’s Mission Control. This asteroid bears the name of the individual who found the fossil Lucy in Ethiopia 50 years ago, the same fossil from which the spacecraft derives its name.
NASA’s Lucy will come within 596 miles (960 kilometers) of the asteroid, which is approximated to be 2.5 miles (4 kilometers) long but significantly narrower. This brief rendezvous is expected to provide scientists with a more precise understanding of its dimensions and form. Lucy will speed past the asteroid at an impressive velocity exceeding 30,000 mph (48,000 kph).
This asteroid is among the many remnants formed from a significant collision approximately 150 million years ago. According to Hal Levison, lead scientist at the Southwest Research Institute, this asteroid is unlikely to be a simple potato shape. It might have a form akin to a bowling pin or resemble a snowman like Arrokoth in the Kuiper Belt, explored by NASA’s New Horizons mission in 2019. Alternatively, it could potentially be two elongated separate entities situated apart.
Levison expressed that the element of surprise makes this mission particularly thrilling. Throughout this flyby, however, Lucy’s communication with Earth will cease momentarily as it orients its antenna toward the asteroid for observation. Levison anticipates acquiring the majority of the scientific data within a day.
Looking ahead, Lucy’s “main event,” as Levison terms it, involves examining the Trojan asteroids co-orbiting the sun with Jupiter. These collections of Trojans trail and precede our solar system’s largest planet as it revolves around the sun. Between 2027 and 2033, Lucy is set to inspect eight of these asteroids, including some paired up in twos.
Lucy made its first asteroid flyby in 2023, sweeping past a small asteroid named Dinkinesh within the main asteroid belt. During this visit, Lucy discovered a mini moon accompanying Dinkinesh.