Earth Science

EARTH AND MARINE SCIENCES Intensive English Program : Grade 9 Earth and marine Sciences (Health Science 5) Subject Code : ว23205 Teacher : Miss Warittha Somjaroen

INDEX

1 :: Our Solar System :: Our planetary system is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity — the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, dwarf planets such as Pluto, dozens of moons and millions of asteroids, comets and meteoroids. Beyond our own solar system, we have discovered thousands of planetary systems orbiting other stars in the Milky Way. 10 Need-to-Know Things about the Solar System 12 ONE OF BILLIONS MEET ME IN THE ORION ARM Our solar system is made up of a star, eight planets Our solar system orbits the center of the Milky Way and countless smaller bodies such as dwarf Galaxy at about 515,000 mph (828,000 kph). We’re planets, asteroids and comets. in one of the galaxy’s four spiral arms. 34 A LONG WAY ROUND SPIRALING THROUGH SPACE It takes our solar system about 230 million years to There are three general kinds of galaxies: elliptical, complete one orbit around the galactic center. spiral and irregular. The Milky Way is a spiral galaxy. 56 GOOD ATMOSPHERE(S) MANY MOONS Our solar system is a region of space. It has no The planets of our solar system—and even some atmosphere. But it contains many worlds— asteroids—hold more than 150 moons in their including Earth—with many kinds of atmospheres. orbits. 78 RING WORLDS LEAVING THE CRADLE The four giant planets—and at least one asteroid— More than 300 robotic spacecraft have explored have rings. None are as spectacular as Saturn’s destinations beyond Earth orbit, including 24 gorgeous rings. astronauts who orbited the moon. 9 10 LIFE AS WE KNOW IT FAR-RANGING ROBOTS Our solar system is the only one known to support NASA’s Voyager 1 is the only spacecraft so far to life. So far, we only know of life on Earth, but leave our solar system. Four other spacecraft will we’re looking for more everywhere we can. eventually hit interstellar space.

2 Solar System Word Search Search for the planets in our solar system. The names can be horizontal, vertical or backward. JUPITER URANUS VENUS MERCURY EARTH NEPTUNE MARS SATURN Name ………………………………….……………………………….…………………… Class M. ………………… No. ………………

3 Our Home Planet Know your planets: Earth All of the planets in the Solar System revolve around the Sun. Some are close to the Sun, while others are farther away. Color in the circle where Earth is on the diagram to the right. Name: Earth is named after the Ancient Greek goddess of mountains and streams. Where Is It?: Earth is the third planet from the sun. Earth and Mars are the only two planets that are the right distance away from the sun so that it is not too hot or too cold to support life. Size: Earth is the fifth largest planet in our solar system. Earth and Venus are nearly the same size, but Earth is slightly larger. What’s It Made Of?: Earth is called a terrestrial planet, which means it is made mostly of rocks. The outer crust contains rocks and metals such as iron and magnesium. The mantle is made of metals and silicates. The core is made of liquid and solid iron and nickel. Life: High amounts of water and metals, as well as a thick atmosphere that keeps a stable temperature, have made Earth a place where life thrives. Scrambles: Unscramble the words for the answer. ……………………………… 1. 70% of the Earth’s surface is covered with this: RTEWA ……………………………… 2. Earth’s internal heat comes from this section: REOC ……………………………… 3. This protects the Earth from the sun’s radiation: ZOEON Name ………………………………………………………………………………. Class M. ………………………. No. …………………………

4 10 Need-to-Know Things about Our Home Planet 12 MEASURING UP THIRD ROCK If the Sun were as tall as a typical front door, Earth orbits our Sun, a star. Earth is the third planet Earth would be the size of a nickel. from the Sun at a distance of about 93 million miles (150 million km). 34 AS THE WORLD TURNS WE'RE ON IT A day on Earth is 24 hours. Earth makes a complete Earth is a rocky planet with a solid and dynamic orbit around the sun (a year in Earth time) in about surface of mountains, canyons, plains and more. 365 days. Most of our planet is covered in water. 56 BREATHE EASY OUR COSMIC COMPANION Earth's atmosphere is 78 percent nitrogen, 21 Earth has one moon. percent oxygen and 1 percent other ingredients— the perfect balance to breathe and live. 78 RINGLESS ORBITAL SCIENCE Earth has no rings. Many orbiting spacecraft study the Earth from above as a whole system—observing the atmosphere, ocean, glaciers, and the solid earth. 9 10 HOME, SWEET HOME PROTECTIVE SHIELD Earth is the perfect place for life as we know it. Our atmosphere protects us from incoming meteoroids, most of which break up in our atmosphere before they can strike the surface. Homework: ............................................................................................................................. ............................................................................ ................................................................................................................................................................................... ...................... ............................................................................................................ ............................................................................................. ............................................................................................................................. ............................................................................ ............................................................................................................................. ............................................................................

Structure of the Earth 5 Formation When the solar system settled into its current layout about 4.5 billion years ago, Earth formed when gravity pulled swirling gas and dust in to become the third planet from the Sun. Like its fellow terrestrial planets, Earth has a central core, a rocky mantle and a solid crust. ➢ Primary waves P-waves can travel through any type of material, including fluids. ➢ Secondary waves S-waves can travel only through solids, as fluids (liquids and gases) do not support shear stresses. Structure Earth is composed of four main layers, starting with an inner core at the planet's center, enveloped by the outer core, mantle and crust. The inner core is a solid sphere made of iron and nickel metals about 759 miles (1,221 kilometers) in radius. There the temperature is as high as 9,800 degrees Fahrenheit (5,400 degrees Celsius). Surrounding the inner core is the outer core. This layer is about 1,400 miles (2,300 kilometers) thick, made of iron and nickel fluids. In between the outer core and crust is the mantle, the thickest layer. This hot, viscous mixture of molten rock is about 1,800 miles (2,900 kilometers) thick and has the consistency of caramel. The outermost layer, Earth's crust, goes about 19 miles (30 kilometers) deep on average on land. At the bottom of the ocean, the crust is thinner and extends about 3 miles (5 kilometers) from the sea floor to the top of the mantle. Name ………………………………………………………………………………. Class M. ………………………. No. …………………………

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