the orbital period is how long it takes for neptune to orbit the sun.
the orbital period is how long it takes for neptune to orbit the sun.
how long it takes for neptune to orbit the sun?
orbital period
2004 kv18









































section::::orbit and classification.









































neptune trojans are resonant trans-neptunian objects (tno) in a mean-motion orbital resonance with neptune. these trojans have a semi-major axis and an orbital period very similar to neptune's (30.10 au; 164.8 years).









































section::::orbit and classification.:orbital instability.









































 is not a primordial neptune trojan, and will leave the region on a relatively short time scale. the orbit of a neptune trojan can only be stable when the eccentricity is less than 0.12. its lifetime as a trailing neptune trojan is on the order of 100,000 years into the future.









































section::::physical properties.









































section::::physical properties.:diameter and albedo.
2004 kv18
many of the planetesimals are also implanted in various orbits beyond neptune's orbit during its migration. while neptune migrates outward several au, the hot classical kuiper belt and the scattered disk are formed as some planetesimals scattered outward by neptune are captured in resonances, undergo an exchange of eccentricity vs inclination via the kozai mechanism, and are released onto higher perihelion, stable orbits. planetesimals captured in neptune's sweeping 2:1 resonance during this early migration are released when an encounter with the ice giant causes its semi-major axis to jump outward, leaving behind a group of low-inclination, low-eccentricity objects in the cold classical kuiper belt with semi-major axes near 44 au. this process avoids close encounters with neptune allowing loosely bound binaries, including 'blue' binaries, to survive. an excess of low-inclination plutinos is avoided due to a similar release of objects from neptune's 3:2 resonance during this encounter. neptune's modest eccentricity following the encounter, or the rapid precession of its orbit, allows the primordial disk of cold classical kuiper belt objects to survive. if neptune's migration is slow enough following this encounter the eccentricity distribution of these objects can be truncated by a sweeping mean-motion resonances, leaving it with a step near neptune's 7:4 resonance. as neptune slowly approaches its current orbit, objects are left in fossilized high-perihelion orbits in the scattered disk. others with perihelia beyond neptune's orbit but not high enough to avoid interactions with neptune remain as a scattering objects, and those that remain in resonance at the end of neptune's migration form the various resonant populations beyond neptune's orbit. objects that are scattered to very large semi-major axis orbits can have their perihelia lifted beyond the influences of the giant planets by the galactic tide or perturbations from passing stars, depositing them in the oort cloud. if the hypothetical planet nine was in its proposed orbit at the time of the instability a roughly spherical cloud of objects would be captured with semi-major axes ranging from a few hundred to a few thousand au.
five-planet nice model