SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 WK

2018 WK

2018 WK is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.897 AU and a period of 0.85 yr.

Aten Observations: 22
Orbital Period · P
0.85 yr
v(q)
44.1 km/s
v(Q)
22.4 km/s
Diameter · ≈
0.01 km
TJ
6.58
Eccentricity · e
0.3271

Orbit and dynamics

Between its closest point (0.604 AU) and its farthest (1.191 AU), the heliocentric distance changes by 0.587 AU over every revolution.

One full revolution takes 0.85 yr (311 days), computed from the semi-major axis of 0.897 AU.

An eccentricity of 0.327 makes the orbit moderately elongated.

Its inclination of 4.22° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 44.1 km/s at perihelion and falls to 22.4 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 = 27.1 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

Astrometry from 22 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5089 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
0.8974 AU
Eccentricity
0.3271
Perihelion
0.604 AU
Aphelion
1.19094 AU
Inclination
4.22°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
60.45°

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
2029-Nov-18 14:37 0.280449 AU
41954552 km
19.37 km/s
2030-Jul-31 23:11 0.393339 AU
58842646 km
13.69 km/s
2031-Feb-06 21:38 0.160349 AU
23987883 km
7.14 km/s
2035-Nov-10 17:15 0.007335 AU
1097322 km
10.36 km/s
2036-Jun-29 04:10 0.410861 AU
61463915 km
14.85 km/s
2037-Feb-26 10:31 0.070359 AU
10525528 km
12.15 km/s
2043-Feb-25 15:03 0.103333 AU
15458439 km
12.84 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
27.1

Orbit Quality

RMS
0.50886
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

Explore asteroids, comets and near-Earth objects with JPL orbital data.