Main-belt asteroid JUNO

Juno

Main-belt asteroid

Numbered 3, Juno is a rocky main-belt asteroid following a noticeably eccentric ellipse around the Sun.

View in the 3D observatory

Illustrative surface and shape · Image credits

Equivalent diameter: 246.596 km
Orbital semimajor axis: 2.671 AU
Model orbital period: 4.365 yr

01 / Overview

Meet Juno

Juno illustrates the diversity of main-belt orbits. Its large change in solar distance between perihelion and aphelion contrasts with Vesta’s more nearly circular path.

Shape and composition

JPL lists Juno’s SMASSII spectral class as Sk, within the silicate-dominated S complex.

Discovery and exploration

The asteroid Juno orbits the Sun; it is a different object from the Juno spacecraft exploring Jupiter.

02 / Key data

Core parameters

Equivalent diameter: 246.596 km
Orbital semimajor axis: 2.671 AU
Model orbital period: 4.365 yr
Rotation period: 7.21 hours
Orbital inclination: 12.987 °
Orbital eccentricity: 0.2557

Data and calculation notes

Asteroid positions use epoch-based JPL orbital snapshots and a two-body approximation. Planetary perturbations and thermal radiation effects are omitted; this is not for close-approach or impact prediction. Except for Ceres's observed near-spherical fallback, scene shapes come from mission or PDS models. True sizes use equivalent radii; asteroids do not participate in eclipse calculations.

03 / Further reading

A closer look

Scale and orbit4

Juno has an equivalent diameter of about 246.596 km: the diameter of a sphere with the same volume.
A year on Juno lasts about 4.37 Earth years.
Using this site's orbital elements, Juno is about 1.988 AU from the Sun at perihelion.
Using this site's orbital elements, Juno is about 3.354 AU from the Sun at aphelion.

Sources

Understanding the orbital model2

An orbital snapshot describes motion near its epoch; planetary gravity changes real orbits over time.
Near-Earth asteroid is an orbital classification; it does not mean an impact on Earth is imminent.

Sources

04 / Sources

Trusted sources

NASA/JPL SBDB — Juno

Image credits

Published global maps or surface-albedo data are applied only to the matching body. Pallas uses Carry et al.'s published K-band relative-albedo map, which covers about 80% of the surface; unobserved pixels are filled with the mean only to keep the matching model continuous. Psyche uses the per-facet relative-albedo map bundled with DAMIT model 1806. Juno has no downloadable global albedo map, so it keeps its own shape, JPL geometric albedo, and spectral material without borrowing another body's texture.

Surface texture：Vernazza et al. (2021), VLT/SPHERE · License · Rendered by ORBIT