SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 SW3

2021 SW3

2021 SW3 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.31 AU once every 1.50 yr.

Amor Observations: 16
Orbital Period · P
1.50 yr
v(q)
31.7 km/s
v(Q)
21.4 km/s
Diameter · ≈
0.05 km
TJ
4.89
Eccentricity · e
0.1948

Orbit and dynamics

Between its closest point (1.055 AU) and its farthest (1.565 AU), the heliocentric distance changes by 0.51 AU over every revolution.

One full revolution takes 1.50 yr (548 days), computed from the semi-major axis of 1.31 AU.

An eccentricity of 0.195 makes the orbit moderately elongated.

A steep inclination of 21.66° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 31.7 km/s at perihelion and falls to 21.4 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 = 24.27 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.05 km.

Observation record and orbit quality

Astrometry from 16 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4875 arcseconds.

Condition code U = 7 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
1.31 AU
Eccentricity
0.1948
Perihelion
1.055 AU
Aphelion
1.565188 AU
Inclination
21.66°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
86.85°

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

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
24.27

Orbit Quality

RMS
0.48754
Condition
7
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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