Moons

 Many moons in our Solar System  They have craters, volcanoes, possibly underground oceans A radar mapping image made by the Cassini spacecraft of a flyover area on Saturn's giant moon Titan showing an ice volcano

Satellites  Natural (not man made) or artificial bodies that revolve around larger bodies such as planets are called satellites  Mercury and Venus have no natural satellites  All other planets have moons (satellites)

Luna: The Moon of the Earth  Solar system is 4.6 billion years old  Based this data from lunar rocks brought back from Apollo mission

Surface of the Moon  Impact craters on the moon tell the age of the moon  If the surface is young, there hasn't been time for many craters to form  Different parts of the surface of the Moon exhibit different amounts of cratering and therefore are of different ages

Lunar Origins  Formation of the moon happened in three steps  1 st Impact – large body collided with earth, blasted part of Earth’s mantle in space  2 nd Ejection – sent mantle debris from Earth and from impacting body (including its iron core)  3 rd Formation – debris orbited around Earth and began to join together

Moon Formation 

Phases of the Moon  /animations/content/moonphase.html /animations/content/moonphase.html  Waxing – sunlit fraction is getting larger  Waning – sunlit fraction is getting smaller  Moon always gets same amount of sun( same as Earth)  You always see same side of the moon

Phases of the Moon  Appearance of the moon from its changing position relative to Earth and the sun  As moon revolves around Earth, amount of sunlight on the side of the moon that faces Earth changes  Called Phases

Waxing and Waning  Waxing – sunlit fraction is getting larger  Waning – sunlit fraction is getting smaller  Crescent – croissant shaped or fingernail clipping  Gibbous – bulging outward

Phases