SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 WS

2018 WS

2018 WS belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.217 AU it takes 1.34 yr to circle the Sun.

Apollo Observations: 84
Orbital Period · P
1.34 yr
v(q)
32.8 km/s
v(Q)
22.2 km/s
Diameter · ≈
0.02 km
TJ
5.23
Eccentricity · e
0.1922

Orbit and dynamics

Between its closest point (0.983 AU) and its farthest (1.451 AU), the heliocentric distance changes by 0.468 AU over every revolution.

One full revolution takes 1.34 yr (490 days), computed from the semi-major axis of 1.217 AU.

An eccentricity of 0.192 makes the orbit moderately elongated.

Its inclination of 1.36° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 32.8 km/s at perihelion and falls to 22.2 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 = 26.5 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

Astrometry from 84 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4341 arcseconds.

Condition code U = 6 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
1.217 AU
Eccentricity
0.1922
Perihelion
0.983 AU
Aphelion
1.450907 AU
Inclination
1.36°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
247.1°

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
2026-Dec-11 18:56 0.300898 AU
45013649 km
13.05 km/s
2030-May-28 18:46 0.378933 AU
56687626 km
6.25 km/s
2034-May-11 13:15 0.418859 AU
62660340 km
6.98 km/s
2038-Apr-25 18:08 0.441604 AU
66063002 km
7.38 km/s
2042-Apr-10 12:42 0.447684 AU
66972647 km
7.50 km/s
2046-Mar-26 03:49 0.431174 AU
64502680 km
7.32 km/s
2050-Mar-09 20:20 0.395965 AU
59235495 km
6.83 km/s
2053-Aug-10 01:43 0.346996 AU
51909818 km
15.28 km/s
2054-Feb-19 11:51 0.339616 AU
50805769 km
5.92 km/s
2057-Aug-20 15:44 0.160700 AU
24040336 km
9.90 km/s
2058-Jan-27 12:33 0.255929 AU
38286500 km
4.37 km/s
2061-Sep-05 21:19 0.018794 AU
2811600 km
4.76 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
26.5

Orbit Quality

RMS
0.43414
Condition
6
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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