Our Solar SystemOur Solar System

A system of eight planets and many other A system of eight planets and many other objects that orbit our sunobjects that orbit our sun

Inner PlanetsInner PlanetsThe 4 solid, rocky planets closest to the The 4 solid, rocky planets closest to the

sun; Mercury, Venus, Earth, Marssun; Mercury, Venus, Earth, Mars

Mercury – 1st planet, moon-like appearance, 4500C during the day, -1750C at night

Venus – 2nd planet, Earth-like, dense CO2 atmosphere, 4640C avg. temperature

Inner Planets (cont.)Inner Planets (cont.)Earth – 3Earth – 3rdrd planet, 150 planet, 150

million km from the sun, million km from the sun, or 1 astronomical unit or 1 astronomical unit (AU)(AU)

Mars – 4th planet, red iron-oxide surface

Outer PlanetsOuter PlanetsThe 4 planets farthest from the sun; Jupiter, The 4 planets farthest from the sun; Jupiter,

Saturn, Uranus, and NeptuneSaturn, Uranus, and NeptuneJupiter – 5th planet,

largest in solar system, gas planet composed of

liquid hydrogen, helium & some ammonia, methane

& water vapor

Saturn – 6th planet, ringed gas planet with the lowest

density

Outer Planets (cont.)Outer Planets (cont.)

Uranus – 7Uranus – 7thth planet, gas planet, gas planet with rotation axis planet with rotation axis

almost parallel to its almost parallel to its revolution planerevolution plane

Neptune – 8th planet, gas planet similar to Uranus with methane gas giving

the blue color

Solar System TermsSolar System TermsSphere – a round, three-dimensional object Sphere – a round, three-dimensional object

whose surface at all points is the same distance whose surface at all points is the same distance from its centerfrom its center

Axis – an imaginary line around which an object Axis – an imaginary line around which an object spinsspins

Solar System Terms (cont.)Solar System Terms (cont.)

Rotation – the spinning of an object around its axisRotation – the spinning of an object around its axis

Revolution – the orbiting of one object around Revolution – the orbiting of one object around another, like Earth revolving around the sunanother, like Earth revolving around the sun

Ellipse – an elongated, closed curve; the shape of Ellipse – an elongated, closed curve; the shape of planetary orbitsplanetary orbits