SpaceAtlas Space Object Data
NASA JPL SBDB · 391151

391151

391151 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.585 AU it takes 4.16 yr to circle the Sun.

Apollo Observations: 403
Orbital Period · P
4.16 yr
v(q)
73.6 km/s
v(Q)
4.7 km/s
Diameter · ≈
1.27 km
TJ
2.62
Eccentricity · e
0.8807

Orbit and dynamics

The path is an ellipse reaching 0.308 AU from the Sun at perihelion and 4.862 AU at aphelion, a radial span of 4.554 AU.

Applying Kepler's third law to a = 2.585 AU gives an orbital period of 4.16 yr, or about 1,518 days.

The high eccentricity (0.881) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 24.8° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 73.6 km/s at perihelion and falls to 4.7 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 1.75 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.084 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

The current orbit solution is based on 403 observations and has a weighted RMS residual of 0.4508 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
2.585 AU
Eccentricity
0.8807
Perihelion
0.308 AU
Aphelion
4.86161 AU
Inclination
24.8°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
313.26°

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
1.745 km
Albedo
0.084
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
17.23

Orbit Quality

RMS
0.4508
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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