SpaceAtlas Space Object Data
NASA JPL SBDB · 311554

311554

311554 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.82 AU and a period of 0.74 yr.

Aten Observations: 622
Orbital Period · P
0.74 yr
v(q)
51.6 km/s
v(Q)
21 km/s
Diameter · ≈
0.64 km
TJ
7
Eccentricity · e
0.4223

Orbit and dynamics

The path is an ellipse reaching 0.474 AU from the Sun at perihelion and 1.166 AU at aphelion, a radial span of 0.692 AU.

Applying Kepler's third law to a = 0.82 AU gives an orbital period of 0.74 yr, or about 271 days.

The high eccentricity (0.422) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 24.38° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 51.6 km/s at perihelion and falls to 21 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 0.38 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.401 points to a comparatively bright, reflective surface.

Observation record and orbit quality

The current orbit solution is based on 622 observations and has a weighted RMS residual of 0.4252 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
0.8199 AU
Eccentricity
0.4223
Perihelion
0.474 AU
Aphelion
1.166144 AU
Inclination
24.38°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
300.93°

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
0.382 km
Albedo
0.401
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
18.72

Orbit Quality

RMS
0.42522
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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