The planets 12/1/14 The planets What is the difference between theTerrestrial and the Jovian Planets? Remember: Terrestrial Planets Mercury, Venus, Earth, Mars Small Close to the Sun Dense/Solid Jovian Planets Jupiter, Saturn, Uranus, Neptune Large Far from the Sun Gas/Not dense Motions of the Planets speeds 225 rotate revolve
Each of the 8 planets of our Solar System areconstantly moving in many differentdirections and __________ First, they are moving with the Solar Systemaround the Milky Way Galaxy in periods ofabout _______ million years! They also __________ around an imaginaryaxis and _________ around the Sun speeds 225 rotate revolve Motions of the Planets Planet Rotation rotation period day
Planets spin on an imaginary axis in a motioncalled __________ The _________ of rotation is the amount oftime it takes for a planet to make one spinaround its axis this determines the lengthof the planets ______ rotation period day Planet Rotation Planets rotation Using the Solar System Data Table in your ESRT, answerthe following questions about the rotations of theplanets: What is the length of a day on Mars? ________________________ Which planet has the shortest period of rotation? _____________ What is the exact length of rotation for the Earth?_____________________ How long is one day on Saturn? ____________________________ Which planet has the longest period of rotation? ______________ Geocentric vs heliocentric Models
What is the difference between theHeliocentric and the Geocentric Models ofthe Solar System? Geo means Earth Earth centered model Helio means Sun Sun centered model https://www.youtube.com/watch?v=iiBIFlvu- X0 Geocentric Model Heliocentric Model Initial Proof Venus goes through phases just like ourmoon! Initial Proof Planet Revolution revolution orbit counterclockwise year
A planets ____________ is its movementaround the Sun in a path called an _______ The planets revolve around the Sun in a______________________ direction The amount of time it takes a planet torevolve around the Sun is considered thatplanets _______ orbit counterclockwise year Planet Revolution Planet revolution Using the Solar System Data Table in your ESRT, answerthe following questions about the revolutions of theplanets: How long does it take the Earth to revolve around the Sun?_________________________ What do we do to account for the lack of a full day in ourrevolution? _______________________________________ Before looking at your Reference Table which planet wouldyou expect to have the shortest period of revolution? Why? Which planet does have the shortest period of revolution?__________________ Before looking at your Reference Table which planet wouldyou expect to have the longest period of revolution? Why? Which planet has the longest period of revolution?__________________ Johannes Kepler Kepler was a 17th centuryGerman mathematician,astronomer, and physicist He was the first todiscover that planets donot orbit in perfectcircles around the Sun Keplers Laws of motion
sk=OS1&FORM=QBVR&pq=keplers%20discov&sc=4- 14&sp=2&qs=PA&sk=OS1#view=detail&mid=001C20E3DC9987C16AAE001C20E3DC9987 C16AAE After studying the planets to the point wherehe almost went insane, Kepler made anincredible discovery that he defined in 3Laws (we are only going to discuss 2 of them) Keplers 1st Law of motion
ellipse The orbit of a planet is an __________ withthe Sun at one of the two ______ An ellipse is an oval shaped orbit foci Keplers 2nd Law of motion
speed A planets orbit will change _________depending on its distance from the Sun When the planet is closest to the Sun, it willbe moving _____ When the planet is farthest from the Sun, itwill be moving _______ fast slow Keplers 2nd law of motion
PLANETS MOVE FASTER CLOSER TO THE SUN! Lets look at the elliptical orbit of a planet
Major Axis Planet Sun Minor Axis Foci The major axis is the longer line that cuts through the two foci! Eccentricity eccentricity eccentric
The ________________ of an ellipse is thedegree of ovalness or how oval-shaped itis The more flattened the orbit is, the more_____________ it is eccentric Eccentricity Eccentricity is a measured value that alwaysfalls between the numbers __ and __ A perfect circle has an eccentricity of _____ What do you think the eccentricity of astraight line would be? 1 zero Eccentricity Formula Eccentricity of ellipse = Distance between foci Length of major axis Eccentricity formula Determine the eccentricity of the followingellipse: 3.578 cm 5.897 cm Eccentricity of Planetary Orbits
Using the Solar System Data Table in your ESRT, answerthe following questions about the eccentricity of theplanetary orbits: What is the eccentricity of Earths orbit? ____________________ Which planet has an orbit closest to a perfect circle?__________________ Which planet has the most eccentric orbit? __________________ What is the eccentricity of the moons orbit around the Earth?___________________________ Inertia and Gravity inertia motion speed
The planets stay in their orbits because of abalance of two things: _________ and gravity Inertia is the concept that an object atrest stays at rest and an object in motionstays in motion unless acted on by anotherforce Inertia acts on the planets by maintainingthe _________ and ________ at which theyrevolve However, the force of gravity affects thismotion! inertia motion speed Inertia and Gravitation
attractive Gravitation is the ____________ force thatexists between two objects The gravitation force depends on two things: The ____________ between the objects The __________ of the two objects distance masses Gravitational Force higher
The larger the object, the _________ itsgravitational pull Gravitational Force higher
The closer two objects are together, the_________ the gravitational pull higher Inertia and Gravitation
So this is why planets move faster when theyare revolving closer to the Sun and slowerwhen they are revolving far from the Sun The Sun is pulling them in toward it causingthe planet to move faster!