SpaceAtlas Space Object Data
NASA JPL SBDB · 2011 UM147

2011 UM147

2011 UM147 is an Amor-type near-Earth asteroid that approaches Earth from beyond our orbit without crossing it, orbiting the Sun at 2.662 AU once every 4.34 yr.

Amor Observations: 143
Orbital Period · P
4.34 yr
v(q)
33.3 km/s
v(Q)
10 km/s
Diameter · ≈
0.67 km
TJ
3.15
Eccentricity · e
0.5377

Orbit and dynamics

The path is an ellipse reaching 1.231 AU from the Sun at perihelion and 4.093 AU at aphelion, a radial span of 2.862 AU.

Applying Kepler's third law to a = 2.662 AU gives an orbital period of 4.34 yr, or about 1,586 days.

The high eccentricity (0.538) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 6.4° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 33.3 km/s at perihelion and falls to 10 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

No direct size measurement is available; from an absolute magnitude of H = 18.61 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.67 km.

Observation record and orbit quality

The current orbit solution is based on 143 observations and has a weighted RMS residual of 0.4903 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
2.662 AU
Eccentricity
0.5377
Perihelion
1.231 AU
Aphelion
4.093357 AU
Inclination
6.4°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
164.41°

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

Orbit Quality

RMS
0.49034
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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