SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 EF4

2018 EF4

2018 EF4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.18 AU it takes 1.28 yr to circle the Sun.

Apollo Observations: 74
Orbital Period · P
1.28 yr
v(q)
33.9 km/s
v(Q)
22.2 km/s
Diameter · ≈
0.02 km
TJ
5.34
Eccentricity · e
0.2093

Orbit and dynamics

Between its closest point (0.933 AU) and its farthest (1.427 AU), the heliocentric distance changes by 0.494 AU over every revolution.

One full revolution takes 1.28 yr (468 days), computed from the semi-major axis of 1.18 AU.

An eccentricity of 0.209 makes the orbit moderately elongated.

The orbital plane is tilted 5.47° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 33.9 km/s at perihelion and falls to 22.2 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 = 26.3 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

Astrometry from 74 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4704 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
1.18 AU
Eccentricity
0.2093
Perihelion
0.933 AU
Aphelion
1.426974 AU
Inclination
5.47°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
191.2°

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
2031-Aug-04 01:21 0.407237 AU
60921812 km
7.28 km/s
2035-Nov-14 23:17 0.147247 AU
22027861 km
9.03 km/s
2036-May-14 17:26 0.294709 AU
44087803 km
4.77 km/s
2040-Aug-22 16:33 0.367123 AU
54920873 km
6.89 km/s
2041-Apr-05 21:02 0.382178 AU
57173038 km
17.16 km/s
2044-Nov-02 12:42 0.342408 AU
51223546 km
15.71 km/s
2045-Jun-12 13:08 0.371142 AU
55521982 km
6.30 km/s
2049-Sep-15 09:20 0.294088 AU
43994906 km
5.92 km/s
2050-Mar-24 21:23 0.153190 AU
22916966 km
10.75 km/s
2054-Jul-03 21:01 0.409141 AU
61206613 km
7.04 km/s
2058-Oct-15 19:04 0.193540 AU
28953108 km
4.09 km/s
2059-Mar-07 02:57 0.001666 AU
249167 km
5.44 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
26.3

Orbit Quality

RMS
0.47043
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.

Keep exploring

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