SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 JS1

2018 JS1

2018 JS1 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.714 AU once every 4.47 yr.

Amor Observations: 141
Orbital Period · P
4.47 yr
v(q)
36.9 km/s
v(Q)
8.9 km/s
Diameter · ≈
0.31 km
TJ
2.97
Eccentricity · e
0.6128

Orbit and dynamics

Between its closest point (1.051 AU) and its farthest (4.377 AU), the heliocentric distance changes by 3.326 AU over every revolution.

One full revolution takes 4.47 yr (1,633 days), computed from the semi-major axis of 2.714 AU.

The high eccentricity (0.613) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 22.39° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 36.9 km/s at perihelion and falls to 8.9 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 = 20.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.31 km.

Observation record and orbit quality

Astrometry from 141 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4266 arcseconds.

Condition code U = 4 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
2.714 AU
Eccentricity
0.6128
Perihelion
1.051 AU
Aphelion
4.377139 AU
Inclination
22.39°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
273.75°

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
2027-May-22 19:05 0.305916 AU
45764432 km
16.43 km/s
2027-Sep-02 22:54 0.495004 AU
74051588 km
8.93 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
20.3

Orbit Quality

RMS
0.42659
Condition
4
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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