SpaceAtlas Space Object Data
NASA JPL SBDB · 2011 KP36

Spacewatch

Spacewatch follows a distinctly cometary orbit: an eccentricity of 0.873 carries it from 4.883 AU at perihelion out to 71.938 AU at aphelion.

comet Observations: 3,711
Orbital Period · P
238 yr
v(q)
18.4 km/s
v(Q)
1.3 km/s
TJ
2.64
Eccentricity · e
0.8729

Orbit and dynamics

The path is an ellipse reaching 4.883 AU from the Sun at perihelion and 71.938 AU at aphelion, a radial span of 67.055 AU.

Applying Kepler's third law to a = 38.41 AU gives an orbital period of 238 yr, or about 86,947 days.

The high eccentricity (0.873) produces a strongly elongated orbit, so the object spends most of its time far from the Sun.

The orbital plane is tilted 18.99° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 18.4 km/s at perihelion and falls to 1.3 km/s at aphelion.

Its Tisserand parameter with respect to Jupiter is T_J = 2.64, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

The measured diameter is 55.1 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.101 points to a comparatively bright, reflective surface.

Observation record and orbit quality

The current orbit solution is based on 3,711 observations and has a weighted RMS residual of 0.4092 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
38.41 AU
Eccentricity
0.8729
Perihelion
4.883 AU
Aphelion
71.938089 AU
Inclination
18.99°
Orbital Period
— yr
Epoch
2457561.5
Mean Anomaly
0.11°

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
55.1 km
Albedo
0.101
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
—

Orbit Quality

RMS
0.40916
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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