SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 SB3

2018 SB3

2018 SB3 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.143 AU it takes 1.22 yr to circle the Sun.

Apollo Observations: 45
Orbital Period · P
1.22 yr
v(q)
33.6 km/s
v(Q)
23.1 km/s
Diameter · ≈
0.03 km
TJ
5.47
Eccentricity · e
0.186

Orbit and dynamics

The path is an ellipse reaching 0.931 AU from the Sun at perihelion and 1.356 AU at aphelion, a radial span of 0.425 AU.

Applying Kepler's third law to a = 1.143 AU gives an orbital period of 1.22 yr, or about 446 days.

An eccentricity of 0.186 makes the orbit moderately elongated.

Its inclination of 2.57° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 33.6 km/s at perihelion and falls to 23.1 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 = 25.6 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.03 km.

Observation record and orbit quality

The current orbit solution is based on 45 observations and has a weighted RMS residual of 0.4436 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
1.143 AU
Eccentricity
0.186
Perihelion
0.931 AU
Aphelion
1.355598 AU
Inclination
2.57°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
156.55°

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

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

Date (UTC)Miss distanceVelocity
2029-Mar-04 12:52 0.285159 AU
42659239 km
5.67 km/s
2029-Sep-20 04:10 0.035485 AU
5308513 km
7.00 km/s
2034-Apr-26 22:05 0.241741 AU
36163999 km
12.47 km/s
2034-Dec-16 09:17 0.348398 AU
52119559 km
6.70 km/s
2040-Feb-16 17:59 0.334111 AU
49982306 km
6.56 km/s
2040-Sep-29 04:41 0.189161 AU
28298056 km
11.27 km/s
2045-May-04 21:50 0.079234 AU
11853293 km
8.05 km/s
2045-Nov-29 08:15 0.302413 AU
45240392 km
5.87 km/s
2051-Feb-03 01:49 0.356251 AU
53294465 km
7.02 km/s
2051-Oct-06 14:20 0.296032 AU
44285694 km
15.15 km/s
2056-May-15 15:02 0.043594 AU
6521535 km
4.85 km/s
2056-Nov-13 13:54 0.249593 AU
37338629 km
4.90 km/s
2062-Oct-11 07:37 0.317540 AU
47503312 km
18.30 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
25.6

Orbit Quality

RMS
0.44361
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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