SCIENCE COUNTDOWNS / NASA / LUCY
Lucy meets its first Trojan asteroid system
Eurybates and its companion Queta are the next doorway into the history of the outer Solar System.
Until the Trojan encounter month begins
WHERE THE MISSION STANDS
The threshold ahead.
Lucy is heading toward the Jupiter Trojan asteroids, which share Jupiter's orbit around the Sun but are not its moons. The mission's first Trojan encounter is with Eurybates and its small companion Queta. A flyby turns a distant point of light into a world whose shape, surface and surroundings can be compared with other asteroid systems.
The Trojans offer clues to the material and rearrangements that shaped the outer Solar System. Lucy investigates several targets because one asteroid cannot represent an entire population. Differences between the encounters may be as informative as similarities.
WHY THE SCIENCE MATTERS
Questions worth returning for.
What history survives on the surface?
Images of craters and terrain provide a record that researchers can compare across Lucy's targets. Fresh exposures and older surfaces can complicate that reading. The useful result is a constrained history, rather than a date assigned from appearance alone.
What makes these asteroids different?
Surface color, spectral measurements and thermal observations probe different properties. Comparing those measurements can test explanations for the variety within the Trojan population. A color difference does not automatically identify a unique substance or birthplace.
What does a companion reveal?
Queta makes this an encounter with a system rather than an isolated body. Its motion can help constrain Eurybates's mass, while observations of both objects inform questions about their relationship. Shape, mass and composition together offer a stronger account than any one image.
CONTINUE THE INVESTIGATION
Follow the thread.
Explore related investigations, Evidence Files, image stories and films.
DATE & SCIENCE SOURCES
NASA's current encounter table lists Eurybates and Queta on August 11, 2027 in Eastern Time. This clock deliberately counts to August 1 at 00:00 UTC, the beginning of the encounter month, rather than converting a timezone-specific calendar listing into an unverified closest-approach instant. Follow NASA for the final timing.
Source review: October 10, 2026. Check the mission agency for later schedule changes.EXPLORE IN 3D / MAP 02
Explore Jupiter before meeting its orbital companions
Visit Jupiter and its moons, then follow Lucy to a different population. Trojan asteroids orbit the Sun along with Jupiter; they are not moons and are not depicted as moons in this view.
Open Jupiter system mapTHE NEXT FILES
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