SpaceAtlas Space Object Data
NASA JPL SBDB · 385P

Hill

Hill follows a distinctly cometary orbit: an eccentricity of 0.402 carries it from 2.555 AU at perihelion out to 5.995 AU at aphelion.

comet Observations: 353
Orbital Period · P
8.84 yr
v(q)
22.1 km/s
v(Q)
9.4 km/s
TJ
2.81
Eccentricity · e
0.4023

Orbit and dynamics

Between its closest point (2.555 AU) and its farthest (5.995 AU), the heliocentric distance changes by 3.44 AU over every revolution.

One full revolution takes 8.84 yr (3,228 days), computed from the semi-major axis of 4.275 AU.

The high eccentricity (0.402) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 16.86° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 22.1 km/s at perihelion and falls to 9.4 km/s at aphelion.

Its Tisserand parameter with respect to Jupiter is T_J = 2.81, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

Neither a measured diameter nor a reliable absolute magnitude is available for Hill, so its physical size remains unconstrained.

Observation record and orbit quality

Astrometry from 353 individual observations underpins this orbit; the fit leaves an RMS residual of 0.7175 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
4.275 AU
Eccentricity
0.4023
Perihelion
2.555 AU
Aphelion
5.994833 AU
Inclination
16.86°
Orbital Period
— yr
Epoch
2456253.5
Mean Anomaly
82.92°

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
—

Orbit Quality

RMS
0.71747
Condition
1
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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