Other Solar System Objects

A moon is a natural satellite Solar systems Moons All are composed of rock & metal Most orbit the outer planets Mercury & Venus have no moons Earth has one moon Mars has two moons Gas giants all have many moons

Number of Satellites Jupiter 63 Saturn 60 Uranus 27 Neptune 13 Mars 2 Earth 1

Dwarf Planets

Dwarf Planet It is neither a planet or satellite. It is a planetary mass object that is in orbit around the sun. Unlike a planet, it cannot clear an orbital region Examples: Pluto, Eris, Ceres The term dwarf planet was adopted in Pluto was demoted from a planet to a dwarf planet 3 years after the discovery of Eris.

Eris

Ceres Largest asteroid in the asteroid belt. Originally was thought to be a planet Now considered a dwarf planet

Ceres

Pluto Distance from sun: A.U. Orbital period 248 years Rotational Period 6.4 days # of Satellites: 3 Best image of Pluto from Hubble Space Telescope

Pluto Mass:.2% of Earth Volume:.6% of Earth 2/3 of the Moon Density: 1.8 g/cm 3 Mainly of rock & ice Temperature: -400 ° F Atmosphere: N 2, CH 4, CO New Horizons 2015

Orbit of Pluto Orbit is tilted about 17º from the ecliptic For about twenty years it was closer to the Sun than Neptune.

Asteroid Belt

Where most asteroids originate. Located between the orbits of Mars and Jupiter. Asteroid Composed mainly of rock and metal.

Asteroid belt

METEORS

Meteors A meteoroid is a small, solid particle that travels through space A meteor is the luminous phenomenon observed when a meteoroid enters Earth’s atmosphere and burns up Popularly called a shooting star. A meteorite is any portion of a meteoroid that reaches Earth’s surface.

Meteor Shower When Earth crosses the trail of a comet, particles left over burn in Earth’s atmosphere, producing bright streaks of light. Meteors are observed to originate from one point in the night sky.

Meteor Shower

Stony Meteorite

Iron Meteorite

Stony/Iron Meteorite

Meteor Crater- Arizona

Comets

Small, icy bodies that have highly eccentric orbits around the Sun. When a comet comes within 3 AU of the Sun, it begins to evaporate and forms a head and one or more tails. The head has a small solid core, surrounded by an envelope of glowing gas.

Where are comets located Short period comets originate in Kuiper belt. Long period comets originate in Oort cloud.

Kuiper Belt

A shadowy disk-like zone beyond the orbit of Neptune (30 to 50 AU from the sun). Populated by dwarf planets and a trillion or more comets.

Oort Cloud

A spherical shell around the solar system Extends from the end of the Kuiper belt 50 A.U. to about 100,000 A.U. (1.5 light years*) *Next closest star is about 4.4 light years away

Haley’s Comet

Hale-Bopp Comet January 1997 Visible even in a city’s light polluted skies Most observed comet in history