2 Gravity Force of attraction between any 2 masses *Weight – the measurement of gravity*Gravitational force- keeps planets in orbitDepends on:Mass of each objectDistance between objects
3 Mercury: 38% of Earth’s Venus: 91% of Earth’s Earth: 100% of Earth’s Mars: 38% of Earth’s Jupiter: 254% of Earth’s Saturn: 108% of Earth’s Uranus: 91% of Earth’s Neptune: 119% of Earth’s Pluto: 8% of Earth’s So what this all means is that a person who weighs 100 pounds on Earth would weigh 38 pounds on Mercury or Mars, 91 pounds on Venus, 254 pounds on Jupiter (!!!), 108 pounds on Saturn, 91 pounds on Uranus, 119 pounds on Neptune, or only 8 pounds on Pluto.
4 Moons and Satellites Satellite- Moon- Any object that orbits (revolves) around another larger objectMoon-Natural satellite of a planet
5 THINK….Write down the difference between rotation and revolution.
6 Stars Big ball of gas that gives off light and heat The way it appears in sky depends on their distance to EarthSUN- closest star to earthConstellation- specific pattern of starsAstronomy- study of stars/planets
7 Our Solar System Our solar system is made up of: Sun Eight planets Their moonsAsteroidsCometsStars
8 Inner Planets- “Terrestrial” Planets The inner four rocky planets at the center of the solar system are:MercuryVenusEarthMars
9 Mercury Planet nearest the sun The smallest planet Covered with cratersHas no moons or ringsAbout size of Earth’s moon
10 Venus Sister planet to Earth Has no moons or rings Hot, thick atmosphereBrightest object in sky besides sun and moon (looks like bright star)Covered with craters, volcanoes, and mountains
11 Earth Third planet from sun Only planet known to have life and liquid waterAtmosphere composed of composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).
12 Mars Fourth planet from sun Appears as bright reddish color in the night skySurface features volcanoes and huge dust stormsHas 2 moons: Phobos and Deimos
13 Outer Planets “Gas Giants” The outer planets composed of gas are :JupiterSaturnUranusNeptune
14 Jupiter Largest planet in solar system Brightest planet in sky 60+ moons, 5 visible from EarthStrong magnetic fieldGiant red spotRings have 3 parts: Halo Ring, Main Ring, Gossamer Ring
15 Saturn 6th planet from sun Beautiful set of rings 31 moons Largest moon, Titan,Easily visible in the night skyVoyager explored Saturn and its rings.
16 Uranus 7th planet from sun Has a faint ring system 27 known moons Covered with cloudsUranus sits on its side with the north and south poles sticking out the sides.
17 Neptune 8th planet from sun Discovered through math 7 known moons Triton largest moonGreat Dark Spot thought to be a hole, similar to the hole in the ozone layer on Earth
18 Activity Come up with your own phrase to help you remember the planets Starting with the planet closest to the sunMy Example:“My Very Educated Mother Just Saw Uncle Ned”