SpaceAtlas Space Object Data
NASA JPL SBDB · 2012 UR158

2012 UR158

2012 UR158 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.232 AU it takes 3.33 yr to circle the Sun.

Apollo Observations: 148
Orbital Period · P
3.33 yr
v(q)
72.1 km/s
v(Q)
5.5 km/s
Diameter · ≈
0.26 km
TJ
3
Eccentricity · e
0.8578

Orbit and dynamics

The path is an ellipse reaching 0.317 AU from the Sun at perihelion and 4.147 AU at aphelion, a radial span of 3.83 AU.

Applying Kepler's third law to a = 2.232 AU gives an orbital period of 3.33 yr, or about 1,218 days.

The high eccentricity (0.858) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

Its inclination of 3.19° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 72.1 km/s at perihelion and falls to 5.5 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 0.63 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.023 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

The current orbit solution is based on 148 observations and has a weighted RMS residual of 0.4547 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
2.232 AU
Eccentricity
0.8578
Perihelion
0.317 AU
Aphelion
4.14661 AU
Inclination
3.19°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
9.38°

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

Predicted close approaches to Earth, from NASA's Center for Near-Earth Object Studies (CNEOS).

Date (UTC)Miss distanceVelocity
2036-Jun-30 16:19 0.114125 AU
17072840 km
26.24 km/s
2073-Jul-03 07:14 0.060851 AU
9103149 km
27.64 km/s

Distances in astronomical units (AU) and kilometres. Source: NASA/JPL CNEOS Close Approach Data API.

Physical Parameters

Diameter
0.629 km
Albedo
0.023
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
20.67

Orbit Quality

RMS
0.45466
Condition
0
Orbit ID
—
Data source: NASA JPL Small-Body Database · NASA CNEOS. 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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