GRADE 5 EARTH SCIENCE UNIT Test Date: ______________ Astronomy Study Guide Know the difference between these two views of the solar system: Geocentric and Heliocentric. Use Twinkle 101/Astronomy 101 log book notes. My Very Educated Mother Just Served Us Nachos (a mnemonic device for remembering the order of the planets in our Solar System) Neptune Uranus Jupiter Mars Earth Venus Mercruy Sun Saturn Outer Planets or Gas Giants Inner or Rocky Planets Asteroid: a small rocky object that orbits the sun. Asteroid Belt Be able to draw or explain a picture that models the relationship between the universe, the galaxies, solar systems, planets and moons. Study Twinkle 102 log book notes. Our solar system is in the Milky Way galaxy. galaxy solar system planet moon universe star Only 2 types of objects in the universe make their own light: stars and meteors. All the other objects (planets, moons, comets, etc.) just reflect light from the stars. Rotation: the spinning of an object around its axis. Earth’s rotation is why the Sun appears to rise in the East and set in the West. Day: the amount of time it takes a planet or moon to complete one rotation around its axis. Earth’s rotation takes 24 hours. axis Day Night Revolution: one complete orbit of an object around another object in space. Year: the amount of time it takes a planet to complete one revolution around the Sun. Earth’s revolution around the sun takes 1 year or ~365 days. Gravity is the force that keeps objects in orbit. Objects with greater mass have more gravity. Sun Page 2 Spring: Northern Hemisphere Fall: Southern Hemisphere. SEASONS Summer: Northern Hemisphere Winter: Northern Hemisphere SUN Winter: Southern Hemisphere Fall: Northern Hemisphere Summer: Southern Hemisphere Spring: Southern Hemisphere. If Earth’s axis was not tilted we would not have seasons. We have seasons on Earth because our axis is tilted AND because we revolve around the sun. As Earth revolves around the Sun, sometimes the axis points towards the sun and sometimes it points away. This way we revolve through the four seasons of winter, spring, summer and fall in one year. Earth’s ROTATION causes the sun to appear to move across the sky, rising in the East and setting in the West. Shadows are longer when the sun is lower in the sky. And shift direction as the sun moves. THE SUN: The star at the center of our solar system. Study textbook pages p 318-321 sunspots: dark, cooler spots on the surface of the sun. solar prominence: bright loops of plasma that flow up from the sun’s surface. solar flares: brief bursts of energy from the sun’s surface solar wind: streams of charged particles (plasma) thrown into space from the sun that can disturb Earth’s compasses and communication systems and can produce auroras (northern and southern lights) in the polar skies. Page 3 Meteoroid: mini-asteroid that orbits the sun. Meteor: a meteoroid that has been pulled by gravity towards the surface of a planet or moon and is burning up due to the force of friction with the planet’s atmosphere, commonly called a “shooting star”. Meteors and stars are the only objects that are a true source of light in space. They PRODUCE light, they do not just reflect it. Meteorite: the part of a meteor that doesn’t burn up and crashes into the surface of a planet or moon making an impact crater. Phases of the Moon (The Lunar Cycle) Phases of the Moon: the different shapes of the moon you see from Earth. The phase of the moon depends on how much of the sunlit side of the moon you see from Earth. It takes about* one “moonth” for the moon to orbit around the Earth and complete a full lunar cycle. Phases of the Moon occur as the moon revolves around the Earth. 1st Quarter Earth Full Moon New Moon Last Quarter “Last Left Lit” Ocean Tides: changes in the water level at the shoreline caused by the moon’s gravitational pull on Earth. The water comes up higher on the beach at High Tide and lower on the beach at Low Tide. The tides change as the Earth rotates. There are two High Tides and two Low Tides each day… that is a total of 4 tidal changes. Atmosphere: the blanket of Earth Both Moon gases that surrounds Earth Atmosphere Impact Craters No Atmosphere Maria: flat dark areas of the Weather Gravity No Weather moon that are covered with Wind Mountains No Liquid Water hardened lava. People used Liquid Water Rocks Maria (Mare) to think these were seas. Moving Water/Rivers Plains Rays Impact crater: bowl shaped Weathering/Erosion Valleys Moonquakes hole in the surface of moons Life Extinct Volcanoes Diameter =3,476 and planets made by Active Volcanoes Rotate (1/4 size of Earth) meteorites. Diameter =12,742km Revolve See Textbook Earthquakes Extinct Volcanoes Rays: fine rock blown out in p322-325 Soil Frozen Water straight lines from a crater Blue Sky after a meteorite hits. Clouds STUDY THIS GUIDE, LOG BOOK NOTES, GREEN FOLDER PAPERS AND CH 7 in your TEXTBOOK!