SpaceAtlas Space Object Data
NASA JPL SBDB · 2020 US66

2020 US66

2020 US66 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.698 AU once every 2.21 yr.

Amor Observations: 30
Orbital Period · P
2.21 yr
v(q)
29.6 km/s
v(Q)
17.6 km/s
Diameter · ≈
0.1 km
TJ
4.15
Eccentricity · e
0.2531

Orbit and dynamics

The path is an ellipse reaching 1.268 AU from the Sun at perihelion and 2.128 AU at aphelion, a radial span of 0.86 AU.

Applying Kepler's third law to a = 1.698 AU gives an orbital period of 2.21 yr, or about 808 days.

An eccentricity of 0.253 makes the orbit moderately elongated.

The orbital plane is tilted 9.53° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 29.6 km/s at perihelion and falls to 17.6 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 = 22.8 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.1 km.

Observation record and orbit quality

The current orbit solution is based on 30 observations and has a weighted RMS residual of 0.5488 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
1.698 AU
Eccentricity
0.2531
Perihelion
1.268 AU
Aphelion
2.127764 AU
Inclination
9.53°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
166.4°

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

Predicted close approaches to Earth, from NASA's Center for Near-Earth Object Studies (CNEOS).

Date (UTC)Miss distanceVelocity
2031-Oct-16 21:43 0.486024 AU
72708222 km
5.79 km/s
2041-Jan-07 18:48 0.396204 AU
59271239 km
2.16 km/s
2051-Nov-29 02:33 0.305105 AU
45643120 km
4.49 km/s
2062-Oct-30 00:57 0.403705 AU
60393455 km
5.39 km/s
2072-Jan-29 11:03 0.460940 AU
68955655 km
2.99 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
22.8

Orbit Quality

RMS
0.54884
Condition
4
Orbit ID
—
Data source: NASA JPL Small-Body Database · NASA CNEOS. 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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