main-belt asteroid
Donaldjohanson
A small, elongated main-belt asteroid flown by NASA's Lucy in 2025, named after the discoverer of the Lucy fossil.
- Distance from Earth today
- 470.9 million km3.148 AU · light: 26 min 11 s
- Distance from the Sun today
- 422.9 million km2.827 AU
- As of
- 3 November 2026position from NASA/JPL orbital elements
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Diameter
- 3.90 km
- Semi-major axis
- 2.384 AU (356.6 million km)
- Perihelion
- 1.939 AU
- Aphelion
- 2.829 AU
- Orbital period
- 3.68 years
- Orbital eccentricity
- 0.187
- Orbital inclination
- 4.4°
- Last perihelion
- 3 December 2024
- Next perihelion
- 9 August 2028
- Minimum orbit distance from Earth’s orbit (MOID)
- 0.956 AU (143.1 million km)
- Albedo
- 0.103
Source of the figures: JPL Small-Body Database (public domain).
Discovery: 1981 – Schelte J. Bus
Description
Donaldjohanson is a small main-belt asteroid discovered by Schelte Bus at Siding Spring Observatory in 1981. It is named after paleoanthropologist Donald Johanson, who discovered the famous fossil hominin known as Lucy – the same Lucy that inspired the name of NASA's mission to the Jupiter trojans. The Lucy spacecraft flew past the asteroid in April 2025 as a rehearsal for its main targets, revealing an elongated body made of two lobes joined by a narrow neck. It is thought to be a fragment from a collision that formed an asteroid family relatively recently in Solar System history.