The History and Classification of Pluto

Dwarf Planet

Pluto's classification since 2006, unlike other planets.

Kuiper Belt Object (KBO)

Celestial bodies located in the Kuiper Belt region.

Trans-Neptunian Object (TNO)

Objects orbiting the Sun beyond Neptune's orbit.

Plutinos

KBOs that share a 2:3 orbital resonance with Neptune.

Orbital Characteristics

Patterns of movement and position of celestial bodies.

Terrestrial Planets

Rocky planets including Mercury, Venus, Earth, Mars.

Jovian Planets

Gas giants including Jupiter, Saturn, Uranus, Neptune.

Elliptical Orbit

An elongated circular path, typical of comets.

Asteroids

Small rocky bodies primarily found in the Asteroid Belt.

Comets

Icy bodies with elliptical orbits, often with tails.

Oort Cloud

A distant spherical shell surrounding the solar system.

Meteoroids

Small debris from asteroids or comets, sand-grain to boulder size.

Meteor

A meteoroid that enters Earth's atmosphere.

Meteorite

A meteoroid that survives atmospheric entry to reach Earth.

Solar Wind

Stream of charged particles emitted by the Sun.

Failed Planet Formation

Pluto does not clear its orbital neighborhood.

Near-Earth Fragments

Large debris that could impact Earth, monitored by NASA.

Planet Definition

A celestial body orbiting a star, cleared neighborhood.

Historical vs. Astronomical Status

Pluto's planet status based on tradition, not criteria.

Tail of Comets

Formed when comets approach the Sun, influenced by solar wind.

Composition of Comets

Made of water, methane, and ice; referred to as dirty snowballs.