SpaceAtlas Space Object Data
NASA JPL SBDB · 399433

399433

399433 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.655 AU it takes 4.33 yr to circle the Sun.

Apollo Observations: 165
Orbital Period · P
4.33 yr
v(q)
51.6 km/s
v(Q)
6.5 km/s
Diameter · ≈
0.68 km
TJ
2.86
Eccentricity · e
0.7766

Orbit and dynamics

The path is an ellipse reaching 0.593 AU from the Sun at perihelion and 4.717 AU at aphelion, a radial span of 4.124 AU.

Applying Kepler's third law to a = 2.655 AU gives an orbital period of 4.33 yr, or about 1,580 days.

The high eccentricity (0.777) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 4.38° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 51.6 km/s at perihelion and falls to 6.5 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

The measured diameter is 1.34 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.021 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

The current orbit solution is based on 165 observations and has a weighted RMS residual of 0.6345 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
2.655 AU
Eccentricity
0.7766
Perihelion
0.593 AU
Aphelion
4.716873 AU
Inclination
4.38°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
249.64°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
1.339 km
Albedo
0.021
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
18.58

Orbit Quality

RMS
0.63455
Condition
0
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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