2/3/20091Small BodiesSmall Bodiesin the Solar Systemin the Solar SystemPSC 203PSC 203OverviewOverview In this section:In this section: What do we know about the formation of the What do we know about the formation of the solar system?solar system? What are the properties of the small bodies in What are the properties of the small bodies in the solar system?the solar system? What happens when small bodies impact the What happens when small bodies impact the Earth? Earth? Solar System ReviewSolar System Review What objects are found in the solar What objects are found in the solar system?system? What objects are classified as small What objects are classified as small bodies?bodies? What are the general properties of the What are the general properties of the terrestrial and jovian planets? terrestrial and jovian planets? FormationFormation What is the solar nebula theory?What is the solar nebula theory? VideosVideos DiscussionDiscussionSummarySummary Cloud of gas and dustCloud of gas and dust Small particles stick togetherSmall particles stick together Build up into larger bodiesBuild up into larger bodies Sun blows extra gas out of inner regionsSun blows extra gas out of inner regions Leftover fragments collide with larger Leftover fragments collide with larger bodiesbodies Sparse small bodies collect in stable areasSparse small bodies collect in stable areasProperties of the planetsProperties of the planets Explanation of planet propertiesExplanation of planet properties TemperaturesTemperatures CompositionComposition SizeSize MoonsMoons SpacingSpacing2/3/20092AsteroidsAsteroids What type of material is left over in What type of material is left over in asteroid belt region? asteroid belt region?  Properties we see …Properties we see …Asteroid ImagesAsteroid ImagesAsteroid BeltAsteroid Belt Main Belt Main Belt –– between between Mars and JupiterMars and Jupiter Unknown number Unknown number probably > 1 millionprobably > 1 million ~ 200 > 100 km~ 200 > 100 km Diagrams misleadingDiagrams misleading Really spread outReally spread outOther AsteroidsOther Asteroids Trojan AsteroidsTrojan Asteroids Along Jupiter's orbitAlong Jupiter's orbit Near Earth AsteroidsNear Earth Asteroids Video (CNN interview)Video (CNN interview) Kuiper Belt ObjectsKuiper Belt Objects Starts just outside of Neptune’s orbitStarts just outside of Neptune’s orbit What type of material do we see here?What type of material do we see here?CometsComets What type of material is left over in the What type of material is left over in the outer regions of the solar system? outer regions of the solar system?  Properties we see …Properties we see …2/3/20093Comets closer inComets closer in What happens as a comet approaches the What happens as a comet approaches the Sun? Sun?  Ice starts to meltIce starts to melt Releases trapped dust and gasReleases trapped dust and gas Sun pushes material out into large tailSun pushes material out into large tailComet DiagramComet DiagramMeteroidsMeteroids Generally small to very smallGenerally small to very small Could be primarily rock, metal, or mixCould be primarily rock, metal, or mix Not easily visible in spaceNot easily visible in space Visible when impact earth’s atmosphereVisible when impact earth’s atmosphereVocabularyVocabulary Meteoroid Meteoroid –– in spacein space Meteor Meteor –– in atmospherein atmosphere Meteorite Meteorite –– on surfaceon surface Meteor shower Meteor shower –– group of meteors coming group of meteors coming from one region of the skyfrom one region of the sky when earth passes through old comet tailwhen earth passes through old comet tailImpact on EarthImpact on Earth Very, very smallVery, very small Burn up in atmosphere unnoticedBurn up in atmosphere unnoticed Very smallVery small Shooting star in airShooting star in air Doesn’t reach surfaceDoesn’t reach surface SmallSmall Bright fire ballBright fire ball Small meteorite left on groundSmall meteorite left on groundImpact on EarthImpact on Earth MediumMedium Bright fire ball, shock waveBright fire ball, shock wave Crater left on surfaceCrater left on surface LargerLarger Massive blast on impactMassive blast on impact LargestLargest … extinction event …… extinction event …2/3/20094Impact videosImpact videos Real Meteor ...Real Meteor ... ShoeMaker Levy ...ShoeMaker Levy ... Understanding Asteroids ...Understanding Asteroids ... (0(0--2 and 52 and 5--8) 8) InIn--class activityclass activity Individually, write down on the index card, Individually, write down on the index card, one remaining question you have about one remaining question you have about something in the solar system.something in the solar