SpaceAtlas Space Object Data
NASA JPL SBDB · 2016 AO9

2016 AO9

2016 AO9 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.148 AU it takes 1.23 yr to circle the Sun.

Apollo Observations: 18
Orbital Period · P
1.23 yr
v(q)
48.8 km/s
v(Q)
15.9 km/s
Diameter · ≈
0.12 km
TJ
5.25
Eccentricity · e
0.5091

Orbit and dynamics

The path is an ellipse reaching 0.563 AU from the Sun at perihelion and 1.732 AU at aphelion, a radial span of 1.169 AU.

Applying Kepler's third law to a = 1.148 AU gives an orbital period of 1.23 yr, or about 449 days.

The high eccentricity (0.509) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 26.99° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 48.8 km/s at perihelion and falls to 15.9 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 = 22.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.12 km.

Observation record and orbit quality

The current orbit solution is based on 18 observations and has a weighted RMS residual of 0.5764 arcseconds.

Condition code U = 8 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
1.148 AU
Eccentricity
0.5091
Perihelion
0.563 AU
Aphelion
1.732447 AU
Inclination
26.99°
Orbital Period
— yr
Epoch
2457393.5
Mean Anomaly
73.5°

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
2026-Dec-31 01:49 0.169634 AU
25376914 km
24.28 km/s
2031-Dec-29 16:02 0.214976 AU
32159890 km
15.94 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
22.3

Orbit Quality

RMS
0.57637
Condition
8
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.

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