SpaceAtlas Space Object Data
NASA JPL SBDB · 2016 US4

2016 US4

2016 US4 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.805 AU and a period of 0.72 yr.

Aten Observations: 62
Orbital Period · P
0.72 yr
v(q)
48.5 km/s
v(Q)
22.7 km/s
Diameter · ≈
0.05 km
TJ
7.18
Eccentricity · e
0.3624

Orbit and dynamics

The path is an ellipse reaching 0.513 AU from the Sun at perihelion and 1.096 AU at aphelion, a radial span of 0.583 AU.

Applying Kepler's third law to a = 0.805 AU gives an orbital period of 0.72 yr, or about 264 days.

An eccentricity of 0.362 makes the orbit moderately elongated.

The orbital plane is tilted 14.96° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 48.5 km/s at perihelion and falls to 22.7 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

No direct size measurement is available; from an absolute magnitude of H = 24.41 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.05 km.

Observation record and orbit quality

The current orbit solution is based on 62 observations and has a weighted RMS residual of 0.4149 arcseconds.

Condition code U = 6 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
0.8046 AU
Eccentricity
0.3624
Perihelion
0.513 AU
Aphelion
1.096187 AU
Inclination
14.96°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
6.46°

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
2027-Feb-09 19:50 0.479353 AU
71710163 km
17.04 km/s
2029-May-22 17:12 0.407295 AU
60930518 km
14.44 km/s
2029-Oct-21 19:25 0.019511 AU
2918811 km
11.77 km/s
2032-Mar-12 02:01 0.491917 AU
73589776 km
20.38 km/s
2034-Sep-26 19:30 0.163726 AU
24493026 km
9.41 km/s
2037-Apr-09 01:06 0.473600 AU
70849559 km
20.00 km/s
2037-Oct-11 21:06 0.416570 AU
62318048 km
23.30 km/s
2039-Aug-22 12:41 0.268454 AU
40160108 km
12.73 km/s
2040-Jan-28 04:58 0.462562 AU
69198339 km
14.65 km/s
2042-May-08 10:16 0.436078 AU
65236292 km
16.81 km/s
2042-Oct-21 04:01 0.151741 AU
22700084 km
15.01 km/s
2044-Aug-26 09:33 0.462045 AU
69120963 km
21.27 km/s
2045-Feb-27 09:01 0.492140 AU
73623087 km
19.49 km/s
2047-Jun-14 08:16 0.372512 AU
55727026 km
10.37 km/s
2047-Oct-14 07:51 0.090920 AU
13601440 km
9.59 km/s
2050-Mar-27 16:15 0.485247 AU
72591937 km
20.54 km/s
2052-Sep-01 07:15 0.223005 AU
33361046 km
10.04 km/s
2053-Jan-09 18:11 0.427126 AU
63897134 km
10.66 km/s
2055-Apr-25 21:27 0.454539 AU
67998065 km
18.48 km/s
2055-Oct-18 05:23 0.262871 AU
39324885 km
18.47 km/s
2057-Aug-23 05:20 0.366937 AU
54893006 km
17.66 km/s
2058-Feb-15 15:15 0.484885 AU
72537809 km
18.01 km/s
2060-May-27 22:56 0.400195 AU
59868298 km
13.50 km/s
2060-Oct-20 18:58 0.009330 AU
1395770 km
10.99 km/s
2063-Mar-16 02:08 0.487847 AU
72980849 km
20.55 km/s

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

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
24.41

Orbit Quality

RMS
0.41488
Condition
6
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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