SpaceAtlas Space Object Data
NASA JPL SBDB · 163691

163691

163691 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.418 AU once every 3.76 yr.

Amor Observations: 450
Orbital Period · P
3.76 yr
v(q)
34.2 km/s
v(Q)
10.7 km/s
Diameter · ≈
1.36 km
TJ
3.03
Eccentricity · e
0.5217

Orbit and dynamics

The path is an ellipse reaching 1.156 AU from the Sun at perihelion and 3.679 AU at aphelion, a radial span of 2.523 AU.

Applying Kepler's third law to a = 2.418 AU gives an orbital period of 3.76 yr, or about 1,373 days.

The high eccentricity (0.522) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 40.8° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 34.2 km/s at perihelion and falls to 10.7 km/s at aphelion.

Its perihelion lies just outside Earth's orbit, which is why it is classed as Earth-approaching rather than Earth-crossing.

Size and surface

The measured diameter is 3.45 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 450 observations and has a weighted RMS residual of 0.4911 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
2.418 AU
Eccentricity
0.5217
Perihelion
1.156 AU
Aphelion
3.679471 AU
Inclination
40.8°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
64.4°

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
3.449 km
Albedo
0.021
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
17.09

Orbit Quality

RMS
0.49111
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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