SpaceAtlas Space Object Data
NASA JPL SBDB · 538979

538979

538979 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.201 AU once every 3.27 yr.

Amor Observations: 53
Orbital Period · P
3.27 yr
v(q)
31.7 km/s
v(Q)
12.7 km/s
Diameter · ≈
0.43 km
TJ
3.45
Eccentricity · e
0.428

Orbit and dynamics

The path is an ellipse reaching 1.259 AU from the Sun at perihelion and 3.143 AU at aphelion, a radial span of 1.884 AU.

Applying Kepler's third law to a = 2.201 AU gives an orbital period of 3.27 yr, or about 1,193 days.

The high eccentricity (0.428) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 22.74° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 31.7 km/s at perihelion and falls to 12.7 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 = 19.61 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.43 km.

Observation record and orbit quality

The current orbit solution is based on 53 observations and has a weighted RMS residual of 0.5555 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
2.201 AU
Eccentricity
0.428
Perihelion
1.259 AU
Aphelion
3.143028 AU
Inclination
22.74°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
61.05°

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
2055-Feb-25 18:04 0.473373 AU
70815567 km
10.83 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
19.61

Orbit Quality

RMS
0.55549
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.

Keep exploring

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