SpaceAtlas Space Object Data
NASA JPL SBDB · 349P

Lemmon

Lemmon follows a distinctly cometary orbit: an eccentricity of 0.3 carries it from 2.501 AU at perihelion out to 4.641 AU at aphelion.

comet Observations: 228
Orbital Period · P
6.75 yr
v(q)
21.5 km/s
v(Q)
11.6 km/s
TJ
3.03
Eccentricity · e
0.2997

Orbit and dynamics

Between its closest point (2.501 AU) and its farthest (4.641 AU), the heliocentric distance changes by 2.14 AU over every revolution.

One full revolution takes 6.75 yr (2,465 days), computed from the semi-major axis of 3.571 AU.

An eccentricity of 0.3 makes the orbit moderately elongated.

The orbital plane is tilted 5.49° relative to the ecliptic.

By the vis-viva equation its orbital speed rises to 21.5 km/s at perihelion and falls to 11.6 km/s at aphelion.

Its Tisserand parameter with respect to Jupiter is T_J = 3.03, a standard discriminator between asteroidal and cometary dynamics.

Size and surface

The measured diameter is 2.98 km, a value from direct size determination rather than from brightness alone.

A geometric albedo of 0.104 points to a comparatively bright, reflective surface.

Observation record and orbit quality

Astrometry from 228 individual observations underpins this orbit; the fit leaves an RMS residual of 0.5234 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
3.571 AU
Eccentricity
0.2997
Perihelion
2.501 AU
Aphelion
4.641229 AU
Inclination
5.49°
Orbital Period
— yr
Epoch
2458923.5
Mean Anomaly
136.05°

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
2.983 km
Albedo
0.104
Density
— g/cm³
Rotation Period
— h
Absolute Magnitude
—

Orbit Quality

RMS
0.52343
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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