SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 SW1

2021 SW1

2021 SW1 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.411 AU it takes 1.68 yr to circle the Sun.

Apollo Observations: 12
Orbital Period · P
1.68 yr
v(q)
38.2 km/s
v(Q)
16.5 km/s
Diameter · ≈
0 km
TJ
4.64
Eccentricity · e
0.3967

Orbit and dynamics

Between its closest point (0.851 AU) and its farthest (1.971 AU), the heliocentric distance changes by 1.12 AU over every revolution.

One full revolution takes 1.68 yr (612 days), computed from the semi-major axis of 1.411 AU.

An eccentricity of 0.397 makes the orbit moderately elongated.

Its inclination of 3.87° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 38.2 km/s at perihelion and falls to 16.5 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 = 29.82 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0 km.

Observation record and orbit quality

Astrometry from 12 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5953 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
1.411 AU
Eccentricity
0.3967
Perihelion
0.851 AU
Aphelion
1.970744 AU
Inclination
3.87°
Orbital Period
— yr
Epoch
2459485.5
Mean Anomaly
28.28°

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
29.82

Orbit Quality

RMS
0.59527
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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