SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 NN4

2018 NN4

2018 NN4 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.674 AU once every 4.37 yr.

Amor Observations: 230
Orbital Period · P
4.37 yr
v(q)
35.1 km/s
v(Q)
9.4 km/s
Diameter · ≈
0.78 km
TJ
2.96
Eccentricity · e
0.576

Orbit and dynamics

The path is an ellipse reaching 1.134 AU from the Sun at perihelion and 4.214 AU at aphelion, a radial span of 3.08 AU.

Applying Kepler's third law to a = 2.674 AU gives an orbital period of 4.37 yr, or about 1,597 days.

The high eccentricity (0.576) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 29.65° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 35.1 km/s at perihelion and falls to 9.4 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 = 18.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.78 km.

Observation record and orbit quality

The current orbit solution is based on 230 observations and has a weighted RMS residual of 0.5089 arcseconds.

Condition code U = 0 means the orbit is very well determined, leaving only a small uncertainty in the future ephemeris.

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
2.674 AU
Eccentricity
0.576
Perihelion
1.134 AU
Aphelion
4.214224 AU
Inclination
29.65°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
286.3°

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
2040-Jun-30 23:26 0.284276 AU
42527133 km
17.05 km/s
2075-Jul-13 20:53 0.192784 AU
28840134 km
17.90 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
18.3

Orbit Quality

RMS
0.50886
Condition
0
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.

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