Solar System - Topic 5 PDF

THE SOLAR SYSTEM Topic 5  The Solar System Consists of: 1.The Sun 2. Planets: 3. The moon(s) 4. Asteroids 5. Comets 6. Meteoroids  The Sun The sun is a medium size STAR that produces its own ENERGY. Is the central and largest body of the...

THE SOLAR SYSTEM Topic 5  The Solar System Consists of: 1.The Sun 2. Planets: 3. The moon(s) 4. Asteroids 5. Comets 6. Meteoroids  The Sun The sun is a medium size STAR that produces its own ENERGY. Is the central and largest body of the solar system. Planets, moons, asteroids, comets, gas and dust move around the sun. The sun is responsible for Earth’s weather and climate. Is the closest star to EARTH which is why is seems so big to us. Other stars seem so much smaller because they are so far away from earth. One million Earths could fit inside the sun. The sun is 150 000 000 km away from the EARTH.  The Sun The sun is a burning sphere, composed mostly of : 75% HYDROGEN GAS & 25% HELIUM GAS. Temperatures within the sun can reach 15 MILLION DEGREES CELCIUS. NUCLEAR REACTIONS within the sun take place and are called NUCLEAR FUSION. This reaction (nuclear fusion) releases large amounts of HEAT and ENERGY. Temperatures outside the sun, a layer called the PHOTOSPHERE provides the right temperature to give earth the perfect temperature. If earth was CLOSER or FURTHER AWAY from the sun, the temperatures on earth would be TOO HIGH or TOO LOW. There would be no LIFE ON EARTH! Only a small fraction of the energy released by the sun actually reaches the earth. The rest just travels out into space or meets the moon or other planets.  OBJECTS AROUND THE SUN In our Solar system there are: 8 planets (and their moons), dwarf planets, asteroids, comets, gas and dust. All planets and other objects in the Solar System have their own features, such as: - Size -Distance from the Sun - Number of moons known, -What they are made of and their surface temperature -Time it takes for one orbit around the sun. ORBIT=: curved path of an object as it moves around another object.  The Planets Inner Planets (rocky plants) Outer Plants (gas Planets) - Mercury - Jupiter - Venus - Saturn - Earth - Uranus - Mars - Neptune  The Planets In order of DISTANCE from the Sun How do I remember the order of planets from the sun? MY – Mercury VERY – Venus EASY – Earth METHOD – Mars JUST – Jupiter SPEEDS – Saturn UP – Uranus NAMING – Neptune PLANETS – Pluto (Dwarf)  SOLID PLANETS SURFACE DISTANCE FROM REVOLUTION PLANETS ABOUT COMPOSITION THE SUN PERIOD IN EARTH DAYS 1. MERCURY Solid planet Has tiny amounts of 58 million km away It takes 88 earth days http://cdn.phys.org/newman/gfx/news/hires/2015/whatsimporta.jpg Hydrogen & Helium. from the sun to orbit around the sun, 2. VENUS Venus spins the Has CO2 and Sulphuric 108 million km away 255 Earth days opposite way to acid clouds. from the sun other planets 3. EARTH The only planet Has Nitrogen & Oxygen It is 150 million km It takes 365.25 Earth http://i.dailymail.co.uk/i/pix/2012/05/11/article-2142884-00A32E15000004B0-324_470x423_popup.jpg able to sustain in the atmosphere away from the sun. days to orbit around life. the sun: 1 year 4. MARS known as the Has Carbon dioxide, 249 million km away It takes 687 Earth http://scrapetv.com/News/News%20Pages/Science/images-3/mars-from-space.jpg “red planet” Nitrogen & Argon in its from the sun. days to orbit around due to the dust. atmosphere. the sun  GAS GIANTS : large planet consisting of hydrogen and helium. https://www.youtube.com/watch?v=ZHAqT4hXnMw SURFACE DISTANCE FROM REVOLUTION PLANETS INFO COMPOSITION THE SUN PERIOD IN EARTH DAYS 5. JUPITER -The largest planet has hydrogen and 780 million km away It takes 12 earth years - Giant gas planet helium in its from the sun. to orbit around the with rings atmosphere. sun. 6. SATURN Known for its has hydrogen and It is 1430 million km It takes 30 Earth years coloured ring made of helium in its away from the sun. to orbit around the ice-coated rock atmosphere. sun fragments. Gas giant with rings 7. URANUS A gas giant with rings hydrogen and 2280 million km takes 84 Earth years helium in its away from the Sun. to orbit around the atmosphere. sun 8. NEPTUNE Named after the has hydrogen and It is 4500 million km It takes 164 Earth roman god of the sea helium in its from the sun years to orbit around due to it’s features. atmosphere. the sun.  What about Pluto? http://images.realclear.com/286017_5_.jpg Pluto, since 2006 has been classified as a DWARF PLANET! Pluto is small, made of rock and methane. Pluto orbits the sun every 247 years. A DWARF PLANET is a celestial body that orbits the sun. The first 5 recognized are CERES PLUTO ERIS MAKEMAKE HUAMEA Check your understanding 1. Provide the names of the planets labelled a, b and c, respectively. (3) 2. Give the name of the planet that: a) takes 255 Earth days to orbit around the sun. b) is known as the “red planet”. c) is 249 million km away for the sun d) has plants and animals living in it e) named after the Roman god of the sea f) is the largest planet in size g) spins the opposite way to other planets 3. Name the central and largest body of the solar system. 4. Give the names of the Two gases that the sun is composed of.  ASTEROIDS http://static1.techinsider.io/image/56e7070e91058436008b63d0-1000-714/shutterstock_297359225.jpg Asteroids are large chunks of rock and metal that orbit around the sun. They are found between mars and jupiter. The word asteroid comes from the Greek word meaning star shaped. http://c.tadst.com/gfx/750x500/asteroid-10-things.jpg?1 Asteroids vary in size from a few metres to hundreds of kilometres. They aren’t perfectly round, they are lumpy. As they orbit the sun, they tumble and spin. Most asteroids orbit the sun in a ring called the asteroid belt located between Mars and Jupiter.  COMETS Comets are large chunks of ice and rock that orbit the sun and then move out beyond pluto. Comets are known as dirty snowballs of the Solar System. A comet is a few kilometers in diameter. Comets are not the same as asteroids. They have a large glowing head with a tail of gases. This tail is created by the ice melting in the comet as it passes the sun. You can see comets without a telescope as they pass. We call them shooting stars. One of the most famous comet it halley’s comet that orbits the sun every 76 years and can be seen from Earth as it passes.  SHORT & LONG PERIOD COMETS Short Period Comets Long period Comets Originate from the kuiper belt Originate from the oort cloud. and orbit for about two hundred Beyond the kuiper belt lies a years. collection of billions of comets This belt is a region of the solar called the oort cloud. system that lies beyond the It is located about one light year planets. from the sun. This belt contains millions of icy The outer limit of the oort cloud objects including some larger defines the boundary of the objects like the dwarf planets. solar system. Orbit the sun for thousands of years.  GRAVITY The solar system looks like a flat disc. Planets move and revolve around the Sun in a pathway called an elliptical orbit. The shape of this orbit is oval. Planets and the sun are held in place by a force of gravity. Each planet has its own force of gravity. Larger planets have a larger force of gravity than smaller planets because they have a greater mass. Because the sun is the largest and heaviest in our solar system, it is able to pull objects towards itself as it has the greatest force. At the same time as being pulled towards the sun, planets are also moving sideways. The combination of the inward pull and the sideways Gravity: the force that attracts a body movement causes planets to rotate around the sun. towards the centre of the earth, or towards any other physical body having mass.  Distance between the orbits of two planets When both planets are on the same side of the sun, they are closest to each other. When they are on opposite sides of the sun, they are farthest away. Close Venus For example, venus is 42 million Distant Sun Earth km from earth at its closest Venus 258 million km point and 258 million km away at its farthest point. This is because planets rotate around the sun at different speeds.  Distance in space Because the distances in space are so LARGE, we usually express them in ASTRONOMICAL UNITS (AU) An astronomical unit is THE DISTANCE FROM EARTH TO THE SUN which is 150 million kilometres. So 1AU = 150 000 000 km. To find the distance between orbits of two planets in AU, subtract the one planet’s distance from sun with the other planet’s distance. EG. (PAGE 79) If Earth is 1AU from the sun and Venus is 0,72AU from the sun, what is the distance between the Earth and Venus? (1AU – 0.72AU = 0.28AU) To convert to km, multiply by 150 000 000 … 0,28 X 150 million = 42 million km  Earths position in the solar system Conditions that support life on The Earth is the third planet from the Earth include: sun. Temperature range during a 24hr It is the only planet supporting life. period & during the year It supports life by providing food, air Amount of water available and water. Amount of light available and its intensity Living things rely on temperature, Availability of gases to ensure water, sunlight and oxygen that earth survival has to offer:  TEMPERATURE Temperature is closely related to the amount of light available provided by the sun as it heats the atmosphere. Temperature is also affected by: altitude water ocean currents Temperatures are cold in the polar regions and hot in the tropics due to the distance from the sun. The distance of the sun’s rays to A are shorter than the distance to B. The nearer to the equator, the warmer the Therefore, more rays reach point A and climate. the temperature will be hotter.  WATER Water is essential for the survival of plants and animals. The amount, frequency and distribution of water influences the distribution of plants and animals. Water can come in the form of: rain mist fog snow and ice Water occurs in three different phases: liquid (in oceans, rivers, dams and lakes) gas (water vapour in the air) solid (in the polar ice caps and ice bergs) The water cycle is controlled by the sun which ensures the survival of life. The water cycle: Movement of water from the atmosphere to Earth then back to the Atmosphere C C D E B A F  The process of the water cycle A – EVAPORATION :The sun causes liquid water molecules to move faster and become water vapour/gas. B – TRANSPIRATION: Plants lose water via leaves releasing water vapour. This is due to photosynthesis which depends on sunlight. C – CONDENSATION: Water vapour from A and B rises into the atmosphere. As it rises, it cools and molecules move slower. Molecules condense and form clouds. Molecules combine inside the clouds and become large and heavy. D – PRECIPITATION Molecules within the clouds become too heavy and fall as precipitation. Precipitation falls as rain, snow, sleet or hail depending on the temperature. E – RUN-OFF Some water seeps into the soil to nourish plants but a lot flows into rivers and lakes. F – COLLECTION : The precipitation eventually runs into the ocean. NB! Without the Sun to start the evaporation process, the water cycle would not exist. The water cycle ensures that water is replenished and ensures that life on earth (plants and animals) will survive.  SUNLIGHT http://65.media.tumblr.com/8082648f8c3c67a0c874d7c703bf2e76/tumblr_mgf2x04U8t1qdsq0ao1_1280.jpg The sun is the main source of energy on this planet. Radiant energy is needed for photosynthesis which ensures that plants get food. Energy flows through food chains, from the sun to plants to herbivores and carnivores. Energy source → Plants → Consumers → Decomposers light plays an important role in determining where plants and animals live. Plants and animals have adapted to the amount of light that is available to them in different regions.  Oxygen The ATMOSPHERE consists of layers of gases that support life and provide protection from the sun’s harmful rays. The main gases in the air that we breath are: NITROGEN 78%- used by plants to produce proteins OXYGEN 21%- produced by plants and used by animals CARBON DIOXIDE 0.03%- produced by animals and used by plants All living things need Oxygen to survive. Without Oxygen, we would not survive on Earth.