SpaceAtlas Space Object Data
Hale-Bopp
NASA JPL SBDB · 1995 O1

Hale-Bopp

Hale-Bopp follows a distinctly cometary orbit: an eccentricity of 0.995 carries it from 0.891 AU at perihelion out to 353.9 AU at aphelion.

comet Observations: 66
Encyclopedia excerpt
Comet Hale–Bopp is a long-period comet that was one of the most widely observed of the 20th century and one of the brightest seen for many decades.
Orbital Period · P
2,363 yr
v(q)
44.6 km/s
v(Q)
0.1 km/s
TJ
0.04
Eccentricity · e
0.995

Orbit and dynamics

Between its closest point (0.891 AU) and its farthest (353.9 AU), the heliocentric distance changes by 353.0 AU over every revolution.

One full revolution takes 2,363 yr (863,020 days), computed from the semi-major axis of 177.4 AU.

The high eccentricity (0.995) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

A steep inclination of 89.29° carries it well above and below the ecliptic plane.

By the vis-viva equation its orbital speed rises to 44.6 km/s at perihelion and falls to 0.1 km/s at aphelion.

Because q < 1 AU and Q > 1 AU, this orbit geometrically intersects the region of Earth's orbit.

Its Tisserand parameter with respect to Jupiter is T_J = 0.04, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

The measured diameter is 60 km, a value from direct size determination rather than from brightness alone.

Its geometric albedo of 0.04 indicates a very dark, carbonaceous-type surface.

Observation record and orbit quality

Astrometry from 66 individual observations underpins this orbit; the fit leaves an RMS residual of 0.3835 arcseconds.

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
177.4 AU
Eccentricity
0.995
Perihelion
0.891 AU
Aphelion
353.913 AU
Inclination
89.29°
Orbital Period
— yr
Epoch
2459837.5
Mean Anomaly
3.88°

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
60.0 km
Albedo
0.04
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
—

Orbit Quality

RMS
0.38349
Condition
—
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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