SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 GM

2018 GM

2018 GM belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.67 AU it takes 2.16 yr to circle the Sun.

Apollo Observations: 167
Orbital Period · P
2.16 yr
v(q)
42.9 km/s
v(Q)
12.4 km/s
Diameter · ≈
0.17 km
TJ
3.91
Eccentricity · e
0.5521

Orbit and dynamics

Between its closest point (0.748 AU) and its farthest (2.592 AU), the heliocentric distance changes by 1.844 AU over every revolution.

One full revolution takes 2.16 yr (788 days), computed from the semi-major axis of 1.67 AU.

The high eccentricity (0.552) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 33.05° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 42.9 km/s at perihelion and falls to 12.4 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 = 21.6 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.17 km.

Observation record and orbit quality

Astrometry from 167 individual observations underpins this orbit; the fit leaves an RMS residual of 0.4235 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
1.67 AU
Eccentricity
0.5521
Perihelion
0.748 AU
Aphelion
2.592007 AU
Inclination
33.05°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
257.79°

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-Mar-28 21:16 0.268295 AU
40136430 km
29.15 km/s
2033-Sep-23 16:40 0.361428 AU
54068857 km
17.91 km/s
2046-Apr-26 22:03 0.335546 AU
50196957 km
18.10 km/s
2048-Oct-07 05:46 0.357004 AU
53407078 km
29.04 km/s
2059-Apr-08 15:05 0.036829 AU
5509607 km
23.90 km/s
2061-Sep-26 08:29 0.222686 AU
33313302 km
21.02 km/s
2072-Mar-18 18:19 0.470212 AU
70342749 km
34.28 km/s
2074-May-09 16:15 0.482452 AU
72173833 km
17.13 km/s
2076-Oct-12 02:25 0.463866 AU
69393296 km
32.26 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
21.6

Orbit Quality

RMS
0.42347
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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