SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 FH1

2018 FH1

2018 FH1 is an Aten-type near-Earth asteroid whose orbit lies mostly inside that of Earth, with a semi-major axis of 0.938 AU and a period of 0.91 yr.

Aten Observations: 46
Orbital Period · P
0.91 yr
v(q)
36.8 km/s
v(Q)
25.7 km/s
Diameter · ≈
0.02 km
TJ
6.38
Eccentricity · e
0.1771

Orbit and dynamics

Between its closest point (0.772 AU) and its farthest (1.104 AU), the heliocentric distance changes by 0.332 AU over every revolution.

One full revolution takes 0.91 yr (332 days), computed from the semi-major axis of 0.938 AU.

An eccentricity of 0.177 makes the orbit moderately elongated.

Its inclination of 3.55° keeps it close to the plane of the ecliptic.

By the vis-viva equation its orbital speed rises to 36.8 km/s at perihelion and falls to 25.7 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 = 26.6 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.02 km.

Observation record and orbit quality

Astrometry from 46 individual observations underpins this orbit; the fit leaves an RMS residual of 0.406 arcseconds.

Condition code U = 4 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
0.9381 AU
Eccentricity
0.1771
Perihelion
0.772 AU
Aphelion
1.104238 AU
Inclination
3.55°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
123.27°

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
2028-Mar-16 22:25 0.022923 AU
3429171 km
4.34 km/s
2028-Oct-12 04:41 0.208848 AU
31243290 km
6.36 km/s
2029-Jul-03 11:47 0.256181 AU
38324181 km
12.14 km/s
2037-Mar-23 15:30 0.334432 AU
50030241 km
15.00 km/s
2037-Dec-26 22:11 0.194805 AU
29142421 km
5.33 km/s
2038-Jun-01 23:51 0.101365 AU
15163955 km
3.71 km/s
2038-Aug-10 18:36 0.126615 AU
18941292 km
2.88 km/s
2039-Jun-25 01:03 0.455928 AU
68205930 km
18.32 km/s
2047-Mar-16 04:05 0.132466 AU
19816613 km
8.89 km/s
2047-Nov-14 08:44 0.222842 AU
33336625 km
6.84 km/s
2048-Jul-09 21:02 0.102209 AU
15290218 km
7.27 km/s
2057-Mar-22 12:42 0.045763 AU
6846099 km
3.86 km/s
2057-Oct-06 08:09 0.203896 AU
30502383 km
6.16 km/s
2058-Jul-02 05:11 0.282770 AU
42301823 km
13.00 km/s
2066-Mar-20 22:38 0.267403 AU
40002950 km
12.98 km/s
2066-Dec-10 09:07 0.212493 AU
31788482 km
6.21 km/s
2067-Jul-08 03:19 0.069825 AU
10445715 km
3.64 km/s
2076-Mar-13 15:20 0.014024 AU
2097974 km
5.53 km/s
2076-Oct-24 16:23 0.213693 AU
31967998 km
6.62 km/s
2077-Jul-07 22:26 0.183803 AU
27496595 km
9.96 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
26.6

Orbit Quality

RMS
0.406
Condition
4
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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