SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 AB8

2021 AB8

2021 AB8 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.705 AU once every 4.45 yr.

Amor Observations: 77
Orbital Period · P
4.45 yr
v(q)
34.4 km/s
v(Q)
9.5 km/s
Diameter · ≈
0.36 km
TJ
3.09
Eccentricity · e
0.5657

Orbit and dynamics

Between its closest point (1.175 AU) and its farthest (4.235 AU), the heliocentric distance changes by 3.06 AU over every revolution.

One full revolution takes 4.45 yr (1,625 days), computed from the semi-major axis of 2.705 AU.

The high eccentricity (0.566) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 12.15° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 34.4 km/s at perihelion and falls to 9.5 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 = 19.96 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.36 km.

Observation record and orbit quality

Astrometry from 77 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5104 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
2.705 AU
Eccentricity
0.5657
Perihelion
1.175 AU
Aphelion
4.235219 AU
Inclination
12.15°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
54.85°

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
2030-Mar-12 17:49 0.402981 AU
60285122 km
11.46 km/s
2061-Mar-25 03:23 0.380474 AU
56918046 km
4.95 km/s
2070-Mar-22 14:29 0.337896 AU
50548561 km
7.69 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
19.96

Orbit Quality

RMS
0.51044
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.

Keep exploring

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