SpaceAtlas Space Object Data
NASA JPL SBDB · 2003 GJ21

2003 GJ21

2003 GJ21 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.811 AU once every 2.44 yr.

Amor Observations: 70
Orbital Period · P
2.44 yr
v(q)
33.8 km/s
v(Q)
14.5 km/s
Diameter · ≈
0.09 km
TJ
3.95
Eccentricity · e
0.4008

Orbit and dynamics

Between its closest point (1.085 AU) and its farthest (2.537 AU), the heliocentric distance changes by 1.452 AU over every revolution.

One full revolution takes 2.44 yr (890 days), computed from the semi-major axis of 1.811 AU.

The high eccentricity (0.401) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 7.05° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 33.8 km/s at perihelion and falls to 14.5 km/s at aphelion.

Its perihelion lies just outside Earth's orbit, which is why it is classed as Earth-approaching rather than Earth-crossing.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 22.9 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.09 km.

Observation record and orbit quality

Astrometry from 70 individual observations underpins this orbit; the fit leaves an RMS residual of 0.6649 arcseconds.

Condition code U = 5 indicates a moderately constrained orbit; predictions decades ahead still carry noticeable uncertainty.

About these computed values

Orbital periods, perihelion and aphelion speeds, and diameter estimates on this page are computed by SpaceAtlas from the JPL SBDB orbital elements. They are derived quantities, not values copied from the source catalogue.

Orbital Parameters

Semi-Major Axis
1.811 AU
Eccentricity
0.4008
Perihelion
1.085 AU
Aphelion
2.536849 AU
Inclination
7.05°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
164.3°

Orbit diagram

The Sun sits at the focus (orange). Earth's orbit is the grey circle at 1 AU. The red dot marks the object's position at the catalog epoch.

3D orbit (interactive)

Drag to rotate; scroll or pinch to zoom. The Sun is at the focus (orange), Earth's orbit is the grey ring at 1 AU, and the red dot marks the object's current position.

Close approaches

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
22.9

Orbit Quality

RMS
0.66493
Condition
5
Orbit ID
—
Data source: NASA JPL Small-Body Database . Orbital periods, perihelion and aphelion speeds, and diameter estimates on this page are computed by SpaceAtlas from the JPL SBDB orbital elements. They are derived quantities, not values copied from the source catalogue.

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