SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 NJ

2018 NJ

2018 NJ belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.539 AU it takes 1.91 yr to circle the Sun.

Apollo Observations: 41
Orbital Period · P
1.91 yr
v(q)
34.4 km/s
v(Q)
16.8 km/s
Diameter · ≈
0.01 km
TJ
4.4
Eccentricity · e
0.3449

Orbit and dynamics

Between its closest point (1.008 AU) and its farthest (2.07 AU), the heliocentric distance changes by 1.062 AU over every revolution.

One full revolution takes 1.91 yr (697 days), computed from the semi-major axis of 1.539 AU.

An eccentricity of 0.345 makes the orbit moderately elongated.

Its inclination of 4.68° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 34.4 km/s at perihelion and falls to 16.8 km/s at aphelion.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 28.02 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

Astrometry from 41 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5228 arcseconds.

Condition code U = 5 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
1.539 AU
Eccentricity
0.3449
Perihelion
1.008 AU
Aphelion
2.069801 AU
Inclination
4.68°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
45.92°

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
2039-Aug-03 12:02 0.028982 AU
4335580 km
5.87 km/s
2041-May-23 01:21 0.408241 AU
61071988 km
18.16 km/s
2060-Sep-16 09:09 0.341818 AU
51135191 km
15.92 km/s
2062-Jun-22 00:35 0.050224 AU
7513432 km
7.42 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
28.02

Orbit Quality

RMS
0.52276
Condition
5
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.