SpaceAtlas Space Object Data
NASA JPL SBDB · 1999 GL4

1999 GL4

1999 GL4 belongs to the Apollo group of near-Earth asteroids, whose orbits cross the path of Earth; with a semi-major axis of 2.119 AU it takes 3.08 yr to circle the Sun.

Apollo Observations: 48
Orbital Period · P
3.08 yr
v(q)
41.1 km/s
v(Q)
10.2 km/s
Diameter · ≈
0.38 km
TJ
3.47
Eccentricity · e
0.6026

Orbit and dynamics

The path is an ellipse reaching 0.842 AU from the Sun at perihelion and 3.396 AU at aphelion, a radial span of 2.554 AU.

Applying Kepler's third law to a = 2.119 AU gives an orbital period of 3.08 yr, or about 1,127 days.

The high eccentricity (0.603) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 7.26° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 41.1 km/s at perihelion and falls to 10.2 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 = 19.88 and an assumed geometric albedo of 0.14, the diameter works out to roughly 0.38 km.

Observation record and orbit quality

The current orbit solution is based on 48 observations and has a weighted RMS residual of 0.6095 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
2.119 AU
Eccentricity
0.6026
Perihelion
0.842 AU
Aphelion
3.395909 AU
Inclination
7.26°
Orbital Period
— yr
Epoch
2461200.5
Mean Anomaly
315.55°

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

No close approaches to Earth are currently on record for this object.

Physical Parameters

Diameter
— km
Albedo
—
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
19.88

Orbit Quality

RMS
0.60952
Condition
6
Orbit ID
—
Data source: NASA JPL Small-Body Database . 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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