SpaceAtlas Space Object Data
NASA JPL SBDB · 311321

311321

311321 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 1.827 AU once every 2.47 yr.

Amor Observations: 208
Orbital Period · P
2.47 yr
v(q)
29.9 km/s
v(Q)
16.2 km/s
Diameter · ≈
0.67 km
TJ
3.78
Eccentricity · e
0.2965

Orbit and dynamics

The path is an ellipse reaching 1.285 AU from the Sun at perihelion and 2.369 AU at aphelion, a radial span of 1.084 AU.

Applying Kepler's third law to a = 1.827 AU gives an orbital period of 2.47 yr, or about 902 days.

An eccentricity of 0.296 makes the orbit moderately elongated.

A steep inclination of 34.71° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 29.9 km/s at perihelion and falls to 16.2 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 0.58 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.172 points to a comparatively bright, reflective surface.

Observation record and orbit quality

The current orbit solution is based on 208 observations and has a weighted RMS residual of 0.5498 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
1.827 AU
Eccentricity
0.2965
Perihelion
1.285 AU
Aphelion
2.368705 AU
Inclination
34.71°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
196.29°

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
0.583 km
Albedo
0.172
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
18.61

Orbit Quality

RMS
0.5498
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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