SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 NK4

2018 NK4

2018 NK4 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.704 AU once every 2.22 yr.

Amor Observations: 23
Orbital Period · P
2.22 yr
v(q)
33.9 km/s
v(Q)
15.4 km/s
Diameter · ≈
0.03 km
TJ
4.11
Eccentricity · e
0.3768

Orbit and dynamics

Between its closest point (1.062 AU) and its farthest (2.346 AU), the heliocentric distance changes by 1.284 AU over every revolution.

One full revolution takes 2.22 yr (812 days), computed from the semi-major axis of 1.704 AU.

An eccentricity of 0.377 makes the orbit moderately elongated.

Its inclination of 0.75° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 33.9 km/s at perihelion and falls to 15.4 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 = 25.2 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.03 km.

Observation record and orbit quality

Astrometry from 23 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4241 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
1.704 AU
Eccentricity
0.3768
Perihelion
1.062 AU
Aphelion
2.346067 AU
Inclination
0.75°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
209.28°

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

Predicted close approaches to Earth, from NASA's Center for Near-Earth Object Studies (CNEOS).

Date (UTC)Miss distanceVelocity
2047-May-04 03:04 0.289993 AU
43382357 km
17.96 km/s
2058-Aug-06 15:50 0.216917 AU
32450388 km
14.18 km/s
2067-May-21 17:25 0.125714 AU
18806555 km
9.72 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
25.2

Orbit Quality

RMS
0.4241
Condition
7
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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