SpaceAtlas Space Object Data
NASA JPL SBDB · 2009 UD

2009 UD

2009 UD belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.039 AU it takes 1.06 yr to circle the Sun.

Apollo Observations: 81
Orbital Period · P
1.06 yr
v(q)
33 km/s
v(Q)
25.9 km/s
Diameter · ≈
0.01 km
TJ
5.89
Eccentricity · e
0.1215

Orbit and dynamics

Between its closest point (0.913 AU) and its farthest (1.165 AU), the heliocentric distance changes by 0.252 AU over every revolution.

One full revolution takes 1.06 yr (387 days), computed from the semi-major axis of 1.039 AU.

An eccentricity of 0.121 makes the orbit moderately elongated.

Its inclination of 4.41° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 33 km/s at perihelion and falls to 25.9 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

No direct size measurement is available; from an absolute magnitude of H = 27.2 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.01 km.

Observation record and orbit quality

Astrometry from 81 individual observations underpins this orbit; the fit leaves an RMS residual of 0.657 arcseconds.

Condition code U = 5 indicates a moderately constrained orbit; predictions decades ahead still carry noticeable uncertainty.

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
1.039 AU
Eccentricity
0.1215
Perihelion
0.913 AU
Aphelion
1.165238 AU
Inclination
4.41°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
187.55°

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
27.2

Orbit Quality

RMS
0.657
Condition
5
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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