Harcourt Science Unit D Chapter 3 Mrs. Strand Lockwood Middle School

Chapter Project

Solar System Terms to know –Planetary system –Asteroid –Meteoroid –Comet –Astronomical unit –Light year

Organization of the Solar System There have been various models over time. There are two basic theories –Geocentric –Heliocentric There are two basic orbital patterns –Elliptical –Circular

Structure of the Solar System Sun Planets Moons Asteroids Meteoroids –M–Meteors –M–Meteorites Comets –W–What is the difference between a planet and a moon? docs/media/space- environment/gaspra.gif&imgrefurl= pace-environment/1-asteroid-planetiod- meteoroid.html&h=440&w=523&sz=100&hl=en&start=3&tbnid=BDqORudhAqNsvM: &tbnh=110&tbnw=131&prev=/images%3Fq%3Dmeteoroid%26svnum%3D10%26hl%3 Den%26lr%3D%26sa%3DG s/StarChild/solar_system_level2/fireball_big.gif&imgrefurl= sfc.nasa.gov/docs/StarChild/solar_system_level2/peekskill.html&h=270&w= 468&sz=52&hl=en&start=8&tbnid=pFWbhRdf87zYMM:&tbnh=74&tbnw= 128&prev=/images%3Fq%3Dmeteoroid%26svnum%3D10%26hl%3Den%26 lr%3D%26sa%3DG mgrefurl= 4&sz=20&hl=en&start=17&tbnid=Ku0KHoUFvLAaRM:&tbnh=119&tbnw=66&prev=/ images%3Fq%3Dmeteoroid%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DG comet.jpg&imgrefurl= =6&tbnid=JFAv4ExC3iWa1M:&tbnh=107&tbnw=143&prev=/images%3Fq%3Dcomet%26svnum %3D10%26hl%3Den%26lr%3D%26sa%3DG

Astronomical Units and Light-Years 93,000,000 miles or 150,000,000 KM distance from sun to earth = 1 AU Usually used to measure distances between planets 5,900,000, 000 miles or 9,500,000,000 KM distance from the sun to the nearest star Light years usually used To measure distance to stars

Cycles of Planets Terms to know: –Rotation –Axis –Revolution –Orbit –Ellipse

Planets rotate on their axis Each day, 24 hours on Earth, is one rotation. Each year, 365 1/4 days on Earth is one revolution.

Orbits Elliptical –Perihelion –Aphelion How planets move in their orbits –Property of inertia

Wobbly planets Precession of the Earth How do we even know this happens? –The North star changes from time to time. See chart pg D90

Why do planets have seasons? Terms to know: –Season –Axial tilt

Earth Seasons Are we pointing towards the sun or away from it? –Autumnal Equinox Dates? –Winter Solstice Dates? –Vernal Equinox Dates? –Summer Solstice Dates? Hmmmmm… How does the tilt of the earth affect temperature?

What… Still looking to the stars for answers?

Why are seasons on Mars so much more extreme? Angle of axis Shape of orbit Do you think there are planets with NO seasons? Why or why not?

Phases of the moon Terms to know: –Phases –First quarter –Third quarter –Waning –Waxing p:// oBriZfI2M:&tbnh=105&tbnw=140&prev=/images%3Fq%3Dmoon%2Bphases%26svnum%3D10%26hl%3Den%26lr%3 D%26sa%3DG

Phases of the moon Have you ever wondered why the moon appears larger in the early evening, than later at night?