SpaceAtlas Space Object Data
NASA JPL SBDB · 2015 XT129

2015 XT129

2015 XT129 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.709 AU once every 2.23 yr.

Amor Observations: 228
Orbital Period · P
2.23 yr
v(q)
32.7 km/s
v(Q)
15.9 km/s
Diameter · ≈
0.14 km
TJ
4.12
Eccentricity · e
0.3476

Orbit and dynamics

The path is an ellipse reaching 1.115 AU from the Sun at perihelion and 2.303 AU at aphelion, a radial span of 1.188 AU.

Applying Kepler's third law to a = 1.709 AU gives an orbital period of 2.23 yr, or about 816 days.

An eccentricity of 0.348 makes the orbit moderately elongated.

Its inclination of 1.01° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 32.7 km/s at perihelion and falls to 15.9 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 = 21.98 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.14 km.

Observation record and orbit quality

The current orbit solution is based on 228 observations and has a weighted RMS residual of 0.4543 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
1.709 AU
Eccentricity
0.3476
Perihelion
1.115 AU
Aphelion
2.303048 AU
Inclination
1.01°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
234.24°

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
2054-Jan-27 21:12 0.187870 AU
28104977 km
3.36 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
21.98

Orbit Quality

RMS
0.4543
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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