Nomenclature

Nomenclature#

Let’s do some fast definitions:

Asteroids
A general term for rocky minor planets

Trans-Neptunian Objects (TNO)
The most small bodies in our Solar System lies beyond Neptune’s orbit thus called TNOs.

  • Kuiper Belt Objects (KBO)
    Icy bodies living in the Kuiper belt (low inclination and eccentricity orbits) that are also TNOs.

    The most famous KBO is Pluto (first discovered) and Ceres

Near Earth Objects (NEO)
Objects that come near Earth with perihelia of less than ~1.3 AU.

The dynamical lifetime of NEOs is at max ~\(10^7\) yrs

Trojan Asteroids
Asteroids that orbit the Lagrangian points of Jupiter.

Oort Cloud#

Sedna#

90377 Sedna is a KBO and was discovered at a perihelion of 76 AU and aphelion of 900AU which is phenomenal.

  • Sedna is considered to live in the inner Oort cloud.

  • It is unknown why Sedna orbits so much further than the rest. Most theorize a perturbation of some sort either by stars, a far planet, or came from somewhere else.

Asteroid Statistics#

Size Distribution#

Due to numerous collisions in the early history of the Solar System it,the size distribution of the asteroid follows a power law:

\[\begin{split} \begin{aligned} N(R) &= \int_{R_0}^{R_1}{\frac{N_0}{R_0}\left(\frac{R}{R_0}\right)^{-\zeta} dR}\\ N(R) &= \int_{R}^{R_\text{max}}{\frac{N_0}{\zeta - 1}\left(\frac{R}{R_0}\right)^{-\zeta} dR} \end{aligned} \end{split}\]

Where the second line is the cumulative equation,

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