SpaceAtlas Space Object Data
NASA JPL SBDB · 2016 WF9

2016 WF9

2016 WF9 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.848 AU it takes 4.81 yr to circle the Sun.

Apollo Observations: 181
Orbital Period · P
4.81 yr
v(q)
39.3 km/s
v(Q)
7.9 km/s
Diameter · ≈
0.34 km
TJ
2.89
Eccentricity · e
0.665

Orbit and dynamics

Between its closest point (0.954 AU) and its farthest (4.742 AU), the heliocentric distance changes by 3.788 AU over every revolution.

One full revolution takes 4.81 yr (1,755 days), computed from the semi-major axis of 2.848 AU.

The high eccentricity (0.665) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 15.18° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 39.3 km/s at perihelion and falls to 7.9 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

The measured diameter is 1.08 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.013 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

Astrometry from 181 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5003 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
2.848 AU
Eccentricity
0.665
Perihelion
0.954 AU
Aphelion
4.74192 AU
Inclination
15.18°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
336.41°

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
2045-Dec-30 19:45 0.139343 AU
20845354 km
13.78 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
1.082 km
Albedo
0.013
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
20.08

Orbit Quality

RMS
0.5003
Condition
0
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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