SpaceAtlas Space Object Data
NASA JPL SBDB · 2023 UD4

2023 UD4

2023 UD4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.418 AU it takes 1.69 yr to circle the Sun.

Apollo Observations: 40
Orbital Period · P
1.69 yr
v(q)
33.9 km/s
v(Q)
18.4 km/s
Diameter · ≈
0.01 km
TJ
4.67
Eccentricity · e
0.2957

Orbit and dynamics

The path is an ellipse reaching 0.999 AU from the Sun at perihelion and 1.837 AU at aphelion, a radial span of 0.838 AU.

Applying Kepler's third law to a = 1.418 AU gives an orbital period of 1.69 yr, or about 617 days.

An eccentricity of 0.296 makes the orbit moderately elongated.

Its inclination of 1.17° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 33.9 km/s at perihelion and falls to 18.4 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 = 28.02 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

The current orbit solution is based on 40 observations and has a weighted RMS residual of 0.3673 arcseconds.

Condition code U = 6 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
1.418 AU
Eccentricity
0.2957
Perihelion
0.999 AU
Aphelion
1.837303 AU
Inclination
1.17°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
200.35°

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
2028-Jul-15 18:39 0.438410 AU
65585186 km
5.20 km/s
2028-Dec-12 18:20 0.370690 AU
55454368 km
16.13 km/s
2045-Sep-03 11:15 0.120579 AU
18038368 km
10.04 km/s
2050-Nov-27 17:41 0.067867 AU
10152785 km
8.50 km/s
2067-Aug-22 19:26 0.361724 AU
54113095 km
15.78 km/s
2068-Jan-22 08:45 0.436555 AU
65307676 km
5.65 km/s
2072-Oct-26 08:01 0.006427 AU
961461 km
4.23 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
28.02

Orbit Quality

RMS
0.3673
Condition
6
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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