SpaceAtlas Space Object Data
NASA JPL SBDB · 21P

Giacobini-Zinner

Giacobini-Zinner follows a distinctly cometary orbit: an eccentricity of 0.711 carries it from 1.013 AU at perihelion out to 5.987 AU at aphelion.

comet Observations: 1,993
Orbital Period · P
6.55 yr
v(q)
38.7 km/s
v(Q)
6.5 km/s
TJ
2.47
Eccentricity · e
0.7105

Orbit and dynamics

The path is an ellipse reaching 1.013 AU from the Sun at perihelion and 5.987 AU at aphelion, a radial span of 4.974 AU.

Applying Kepler's third law to a = 3.5 AU gives an orbital period of 6.55 yr, or about 2,392 days.

The high eccentricity (0.711) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 32° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 38.7 km/s at perihelion and falls to 6.5 km/s at aphelion.

Its Tisserand parameter with respect to Jupiter is T_J = 2.47, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

The measured diameter is 2 km, a value from direct size determination rather than from brightness alone.

Observation record and orbit quality

The current orbit solution is based on 1,993 observations and has a weighted RMS residual of 0.515 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
3.5 AU
Eccentricity
0.7105
Perihelion
1.013 AU
Aphelion
5.98675 AU
Inclination
32.0°
Orbital Period
— yr
Epoch
2458070.5
Mean Anomaly
314.66°

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

Orbit Quality

RMS
0.51504
Condition
0
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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