SpaceAtlas Space Object Data
NASA JPL SBDB · 2016 TD18

2016 TD18

2016 TD18 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.768 AU it takes 2.35 yr to circle the Sun.

Apollo Observations: 62
Orbital Period · P
2.35 yr
v(q)
35.9 km/s
v(Q)
14 km/s
Diameter · ≈
0.07 km
TJ
3.99
Eccentricity · e
0.4388

Orbit and dynamics

The path is an ellipse reaching 0.992 AU from the Sun at perihelion and 2.544 AU at aphelion, a radial span of 1.552 AU.

Applying Kepler's third law to a = 1.768 AU gives an orbital period of 2.35 yr, or about 859 days.

The high eccentricity (0.439) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 3.35° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 35.9 km/s at perihelion and falls to 14 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 = 23.56 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.07 km.

Observation record and orbit quality

The current orbit solution is based on 62 observations and has a weighted RMS residual of 0.5949 arcseconds.

Condition code U = 5 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
1.768 AU
Eccentricity
0.4388
Perihelion
0.992 AU
Aphelion
2.543798 AU
Inclination
3.35°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
10.99°

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
2056-Nov-08 01:21 0.205327 AU
30716513 km
12.51 km/s
2064-Jan-06 16:48 0.020629 AU
3086116 km
6.29 km/s
2071-Feb-17 06:45 0.356451 AU
53324303 km
19.31 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
23.56

Orbit Quality

RMS
0.59488
Condition
5
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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