Not just rocks

Look: 8 asteroids will unlock the secrets of Jupiter's Trojans

Lucy will be the first to visit this fleet of primordial bodies.

Originally Published: 
Jonathan North via NASA Conceptual Image Lab

NASA’s Lucy mission, which launches October 16, will be the first to visit a mysterious, ancient cluster of space rocks called the Trojan Asteroids.

What’s so special about the Trojans?

Unlike the more distant Kuiper Belt, these asteroids share an orbit with Jupiter. They’re incredibly old and likely formed with the early Solar System.


Lucy has its eyes on 7 main asteroids that could hold surprising secrets about the Solar System’s evolution.

Here are the 7 targets Lucy will visit, and why they’re significant:

8. Donaldjohanson

Yes, that teeny, tiny speck of rock.


In April 2025 — on the way to the Trojans — Lucy will test its instruments on this asteroid fragment.

It’s much smaller than Lucy’s other targets — only 2.5 miles wide.

Queta is a small asteroid and the satellite of another target — Eurybates. It was discovered in 2020 by the Lucy team and is named after Mexican track and field athlete Norma Enriqueta “Queta” Basilio Sotelo.

6. Eurybates

Measuring in at 40 miles wide, Eurybates is the first Trojan asteroid Lucy will encounter. This will happen in 2027.

It’s a C-type asteroid, which is rare for Jupiter’s Trojans, but not elsewhere in the Solar System.

Researchers hope to uncover why that’s the case.

5. Polymele

Polymele is the smallest of the Trojans Lucy will explore, at 13 miles wide.

Southwest Research Institute

The reddish rock is a P-type asteroid — the first ever to be explored by a spacecraft.

This should happen around September 2027.

4. Leucus

A single day on slowly-rotating Leucus is 446 hours long and the mysteries of this D-type asteroid only start there.

Observations from Earth suggest it may be extremely elongated, but Lucy won’t know for sure until it can examine the rock up close.

3. Orus

Though it is larger than Leucus, the 31.5 mile-wide Orus has a similar composition as its neighbor.


Orus will give researchers another comparison point for understanding D-type asteroids, a class of which very little is known.

2. Patroclus

This asteroid is Lucy’s last stop in 2033, but it will make for a truly grand finale.


Patroclus is the first in a binary pair of P-type asteroids — basically, two asteroids that orbit each other while they travel around the Sun.

1. Menoetius

Menoetius is Patroclus’ twin asteroid.

The Hubble Space Telescope captured this image of them in 2018.

Astronomers predict that the pair is an artifact from the primordial Solar System — nuggets from the early formation of the place we call home.

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