SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 JO

2021 JO

2021 JO belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.236 AU it takes 1.37 yr to circle the Sun.

Apollo Observations: 44
Orbital Period · P
1.37 yr
v(q)
62.2 km/s
v(Q)
11.5 km/s
Diameter · ≈
0.17 km
TJ
4.77
Eccentricity · e
0.6868

Orbit and dynamics

The path is an ellipse reaching 0.387 AU from the Sun at perihelion and 2.085 AU at aphelion, a radial span of 1.698 AU.

Applying Kepler's third law to a = 1.236 AU gives an orbital period of 1.37 yr, or about 502 days.

The high eccentricity (0.687) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 37.2° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 62.2 km/s at perihelion and falls to 11.5 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 21.63 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.17 km.

Observation record and orbit quality

The current orbit solution is based on 44 observations and has a weighted RMS residual of 0.3664 arcseconds.

Condition code U = 8 signals a poorly constrained orbit, so its future path should be treated as provisional.

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
1.236 AU
Eccentricity
0.6868
Perihelion
0.387 AU
Aphelion
2.084885 AU
Inclination
37.2°
Orbital Period
— yr
Epoch
2459338.5
Mean Anomaly
66.23°

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
21.63

Orbit Quality

RMS
0.3664
Condition
8
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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