SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 SN

2018 SN

2018 SN is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.684 AU once every 2.19 yr.

Amor Observations: 116
Orbital Period · P
2.19 yr
v(q)
31.6 km/s
v(Q)
16.7 km/s
Diameter · ≈
0.16 km
TJ
4.14
Eccentricity · e
0.31

Orbit and dynamics

The path is an ellipse reaching 1.162 AU from the Sun at perihelion and 2.206 AU at aphelion, a radial span of 1.044 AU.

Applying Kepler's third law to a = 1.684 AU gives an orbital period of 2.19 yr, or about 798 days.

An eccentricity of 0.31 makes the orbit moderately elongated.

The orbital plane is tilted 14.05° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 31.6 km/s at perihelion and falls to 16.7 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 = 21.7 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.16 km.

Observation record and orbit quality

The current orbit solution is based on 116 observations and has a weighted RMS residual of 0.4756 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
1.684 AU
Eccentricity
0.31
Perihelion
1.162 AU
Aphelion
2.20604 AU
Inclination
14.05°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
196.64°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
21.7

Orbit Quality

RMS
0.47562
Condition
5
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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