SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 OK

2018 OK

2018 OK is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.322 AU once every 3.54 yr.

Amor Observations: 48
Orbital Period · P
3.54 yr
v(q)
34.5 km/s
v(Q)
11.1 km/s
Diameter · ≈
0.11 km
TJ
3.38
Eccentricity · e
0.5147

Orbit and dynamics

The path is an ellipse reaching 1.127 AU from the Sun at perihelion and 3.517 AU at aphelion, a radial span of 2.39 AU.

Applying Kepler's third law to a = 2.322 AU gives an orbital period of 3.54 yr, or about 1,292 days.

The high eccentricity (0.515) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 5.14° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 34.5 km/s at perihelion and falls to 11.1 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 = 22.5 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.11 km.

Observation record and orbit quality

The current orbit solution is based on 48 observations and has a weighted RMS residual of 0.3648 arcseconds.

Condition code U = 4 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
2.322 AU
Eccentricity
0.5147
Perihelion
1.127 AU
Aphelion
3.517133 AU
Inclination
5.14°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
76.61°

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
22.5

Orbit Quality

RMS
0.36476
Condition
4
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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