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Fact file

Type

Space probe

Launch

16 October 2021

Interesting facts about Lucy

• Lucy is the first probe to visit Jupiter's Trojans – the two swarms of asteroids ahead of and behind Jupiter.
• It is named after “Lucy”, the famous 3.2-million-year-old skeleton of an early human ancestor – just as the fossil shows where humans came from, the Trojans should show where the planets came from.
• At its first asteroid, Dinkinesh, it made a surprise discovery in 2023: a mini-moon.

Frequently asked questions about Lucy

The mission

A NASA mission with two huge round solar panels, each more than 7 m across.

Technology and flight

The Trojans are thought to be “fossils” of planet formation – unchanged for 4.5 billion years.

Discoveries

Visits to eight asteroids are planned; the last, in 2033, is the double asteroid pair Patroclus and Menoetius in the trailing swarm.

For comparison

Lucy gains speed at Earth three times in order to fly its complicated looping path.

Mission milestones

1. 16 October 2021Launch at Earth

   Launch on an Atlas V rocket from Cape Canaveral.

2. 16 October 2022Swing-by of Earth (1) at Earth

   First Earth flyby.

3. 1 November 2023Dinkinesh

   Flyby of the small asteroid Dinkinesh – with an unexpected mini-moon.

4. 12 December 2024Swing-by of Earth (2) at Earth

   Second Earth flyby.

5. 20 April 2025Donaldjohanson

   Flyby of an asteroid in the main belt, named after the discoverer of the Lucy fossil.

6. 12 August 2027At the Trojans (leading)

   Arrival in the leading swarm: flyby of Eurybates and its moon Queta (planned).

7. 11 November 2028Orus

   Last visit in the leading swarm (planned).

8. 26 December 2030Swing-by of Earth (3) at Earth

   Third flyby – Lucy moves on to the trailing swarm (planned).

9. 2 March 2033Patroclus and Menoetius

   Flyby of the double asteroid in the trailing swarm (planned).

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