SpaceAtlas Space Object Data
NASA JPL SBDB · 2021 EU4

2021 EU4

2021 EU4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.049 AU it takes 2.93 yr to circle the Sun.

Apollo Observations: 102
Orbital Period · P
2.93 yr
v(q)
43.4 km/s
v(Q)
10 km/s
Diameter · ≈
0.04 km
TJ
3.49
Eccentricity · e
0.6264

Orbit and dynamics

The path is an ellipse reaching 0.766 AU from the Sun at perihelion and 3.332 AU at aphelion, a radial span of 2.566 AU.

Applying Kepler's third law to a = 2.049 AU gives an orbital period of 2.93 yr, or about 1,071 days.

The high eccentricity (0.626) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 13.72° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 43.4 km/s at perihelion and falls to 10 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 = 24.66 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 102 observations and has a weighted RMS residual of 0.3518 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
2.049 AU
Eccentricity
0.6264
Perihelion
0.766 AU
Aphelion
3.332494 AU
Inclination
13.72°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
297.83°

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
2029-Oct-02 18:56 0.425256 AU
63617412 km
29.02 km/s
2070-Oct-06 15:15 0.223589 AU
33448417 km
26.61 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
24.66

Orbit Quality

RMS
0.35175
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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