OTHER SOLAR SYSTEM OBJECTS

Comets, Asteroids, and Meteors

ASTEROIDSAsteroid - rocky body that varies in diameter that has a pitted irregular surface

Some have satellites orbiting them

Thousands orbiting the Sun in asteroid belt

Asteroid Belt - rocky planetesimals that orbit between Mars and Jupiter

Occasionally collide and break into smaller fragments

Asteroid Belt

METEORSMeteoroid - any interplanetary material that enters atmosphere

As it passes through atmosphere it’s heated by friction and burns - produces streak of light called a meteor

Meteorite - a meteor that does not burn up completely and strikes the ground

Produce impact craters

IMPACT CRATERSEvidence of impacts are lost over time - erosion and plate tectonics

Meteor Crater - Arizona

KUIPER BELTKuiper Belt - small group of solar system bodies that are mostly rock and ice that lie outside orbit of Neptune

30 to 50 AU from the Sun

COMETSComets - small, icy bodies that have highly eccentric orbits around sun

Come from oort cloud

Oort Cloud - collection of comets located between Kuiper Belt to 100 000 AU from Sun

Occasionally, their orbit is disturbed by gravity of another object - thrown into inner solar system

COMETSWhen a comet comes close to the sun it evaporates, forming a head and one or more tails

Head - small solid core surrounded by glowing gas

Tail - gas and dust that is pushed away from comet by particles of solar radiation from Sun

Tail always points away from Sun

PERIODIC COMETSPeriodic Comets - comets that repeatedly return to inner solar system (regular permanent orbit around Sun)

Halley’s Comet - 76 year period

Each time it comes near Sun it loses some of its matter, leaving behind a trail of particles left in Earth’s upper atmosphere - meteor shower

Most meteors are caused by dust particles from comets

DWARF PLANETSDwarf Planet - object that, due to its own gravity, is spherical in shape, orbits the Sun, is not a satellite, and has not cleared the area of its orbit of smaller debris.

At least 12 other objects whose classification is undecided

Eris Dysnomia Ceres PlutoCharon