SpaceAtlas Space Object Data
NASA JPL SBDB · 399325

399325

399325 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.146 AU it takes 1.23 yr to circle the Sun.

Apollo Observations: 363
Orbital Period · P
1.23 yr
v(q)
56.9 km/s
v(Q)
13.6 km/s
Diameter · ≈
0.35 km
TJ
5.22
Eccentricity · e
0.6147

Orbit and dynamics

Between its closest point (0.442 AU) and its farthest (1.85 AU), the heliocentric distance changes by 1.408 AU over every revolution.

One full revolution takes 1.23 yr (448 days), computed from the semi-major axis of 1.146 AU.

The high eccentricity (0.615) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 24.43° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 56.9 km/s at perihelion and falls to 13.6 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 0.67 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.039 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

Astrometry from 363 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4521 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
1.146 AU
Eccentricity
0.6147
Perihelion
0.442 AU
Aphelion
1.850446 AU
Inclination
24.43°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
98.21°

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
0.669 km
Albedo
0.039
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
20.06

Orbit Quality

RMS
0.45206
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.

Keep exploring

Explore asteroids, comets and near-Earth objects with JPL orbital data.