SpaceAtlas Space Object Data
NASA JPL SBDB · 2018 GJ1

2018 GJ1

2018 GJ1 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 1.804 AU it takes 2.42 yr to circle the Sun.

Apollo Observations: 275
Orbital Period · P
2.42 yr
v(q)
41.2 km/s
v(Q)
11.9 km/s
Diameter · ≈
0.25 km
TJ
3.86
Eccentricity · e
0.5517

Orbit and dynamics

The path is an ellipse reaching 0.809 AU from the Sun at perihelion and 2.799 AU at aphelion, a radial span of 1.99 AU.

Applying Kepler's third law to a = 1.804 AU gives an orbital period of 2.42 yr, or about 885 days.

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

The orbital plane is tilted 6.8° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 41.2 km/s at perihelion and falls to 11.9 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 = 20.8 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.25 km.

Observation record and orbit quality

The current orbit solution is based on 275 observations and has a weighted RMS residual of 0.4658 arcseconds.

Condition code U = 1 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
1.804 AU
Eccentricity
0.5517
Perihelion
0.809 AU
Aphelion
2.799267 AU
Inclination
6.8°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
101.4°

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
2030-Sep-24 01:29 0.128731 AU
19257943 km
17.19 km/s
2035-Apr-30 21:52 0.071021 AU
10624548 km
16.49 km/s
2047-Sep-02 21:01 0.146097 AU
21855780 km
11.08 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
20.8

Orbit Quality

RMS
0.46576
Condition
1
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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