SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 XG4

2021 XG4

2021 XG4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.086 AU it takes 1.13 yr to circle the Sun.

Apollo Observations: 23
Orbital Period · P
1.13 yr
v(q)
55.7 km/s
v(Q)
14.7 km/s
Diameter · ≈
0.04 km
TJ
5.53
Eccentricity · e
0.5832

Orbit and dynamics

The path is an ellipse reaching 0.453 AU from the Sun at perihelion and 1.719 AU at aphelion, a radial span of 1.266 AU.

Applying Kepler's third law to a = 1.086 AU gives an orbital period of 1.13 yr, or about 413 days.

The high eccentricity (0.583) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 5.94° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 55.7 km/s at perihelion and falls to 14.7 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Size and surface

No direct size measurement is available; from an absolute magnitude of H = 24.87 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.04 km.

Observation record and orbit quality

The current orbit solution is based on 23 observations and has a weighted RMS residual of 0.523 arcseconds.

Condition code U = 9 signals a poorly constrained orbit, so its future path should be treated as provisional.

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
1.086 AU
Eccentricity
0.5832
Perihelion
0.453 AU
Aphelion
1.719355 AU
Inclination
5.94°
Orbital Period
— yr
Epoch
2459556.5
Mean Anomaly
306.72°

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
2064-Dec-12 19:39 0.055008 AU
8229031 km
21.79 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
24.87

Orbit Quality

RMS
0.52298
Condition
9
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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