UNIT 7: Kilo Hōkū - Astronomy & Navigation Teacher s Notes for: The Ordered Solar System Before the students can begin their Tour Through the Solar System they need to have a roadmap. This exercise provides both an internal roadmap, by teaching the students about their learning style, and an external map when they create a model Solar System. The model Solar System can be left up in the classroom for the whole unit so that students can review their progress in each lesson. This section consists of 6 activities. The first 3 activities are core to the learning outcomes and the last 3 are additional that can be done if there is time. Objectives The goal of this unit (Part B of Unit 7) is to teach the order and general properties of the planetary objects in our Solar System. Learning Outcomes To enable students to: Learn there are now 8 planets in the Solar System and why Arrange the objects in our Solar System in the correct order Learn that planets are not equally spaced Learn Gas Giants are bigger and farther apart than terrestrial planets Understand planets are not all alike (e.g., not all the same size), some have atmospheres, some don t, some have moons while others do not Gravity varies on each planet as a function of mass and planet radius Sun is ~ 100 x bigger than Earth Jupiter is ~ 10x bigger than Earth Although Mars is 50% bigger in size relative to Mercury, they have equivalent gravity Explain why the Earth has a gravitational force similar to Saturn, even though Saturn is 8x s bigger and 100x more massive (it is less dense) 1. Optional Surveys: VARK and Multiple Intelligence Have students take the VARK or multiple intelligence surveys at: Multiple Intelligence Survey http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks1/ict/multiple_int/questi ons/questions.cfm Visual, Aural Read/Write, and Kinesthetic (VARK) Survey http://www.vark-learn.com/english/page.asp?p=questionnaire (website addresses listed below). Have the students record their results for the different learning styles. The purpose of taking the surveys: to support those who have learning challenges Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 1
to provide teachers a demographic of how students learn so that they can develop additional learning strategies to target the different learning styles of students to form students for group work so that each learning style is represented In this curriculum we have attempted to stimulate the four different learning styles: Visual, Aural, Reading/Writing and Kinesthetic. 2. Introductory Lecture The Ordered Solar System Show the NASA Powerpoint The Ordered Universe (see preview in Part A of this unit and slideshow on compact disk included in this curriculum), which covers the definitions of a planet, gas giants versus terrestrial planets, and introduces the terms dwarf planet and plutoid. These keywords, plus Kuiper Belt and Asteriod Belt are defined at the end of the accompanying Powerpoint handout. Source: http://www.soest.hawaii.edu/curriculum/tourthroughthesolarsystem/ Discussion topics: 1) Why does the Solar System contain only eight planets and why is Pluto no longer a planet? o Recent discoveries of large objects orbiting the Sun beyond Neptune and Pluto have raised the question, What is a planet? The International Astronomical Union (IAU) has re-examined the way planetary bodies are classified, and in August 2006 it passed a resolution redefining the criteria for planetary status. 2) What three properties define a planet? A planet is defined by three properties: It is a celestial body that orbits the Sun It is massive enough that its own gravity causes it to form in a spherical shape There are no other objects of comparable size other than its own satellites (e.g., moons) in its orbit 3) What do objects in Pluto s orbit have to do with its new classification? An object is considered to have cleared the neighborhood around its orbit when there are no other objects of comparable size within its orbit, except for its own moons. For instance, Pluto shares its orbit with Kuiper Belt objects; thus it has not cleared its orbit and does not meet the requirements for the new definition of a planet. Using this definition, the IAU has determined that our Solar System now has eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 2
4) What is Pluto now known as? Pluto has been reclassified as a dwarf planet, and because it is located beyond the orbit of Neptune, it s also known as a plutoid. Another dwarf planet that is also a plutoid is Eris which is an icy body that is about the same size as Pluto but is farther away from Earth (the distance from Pluto to Eris is almost the same distance as the distance from the Sun to Pluto). It was partly due to the discovery of Eris that the IAU re-defined planets. 5) Is Ceres the same as Eris? Ceres is also a dwarf planet, but it is not a plutoid because it is not located beyond the orbit of Neptune. Ceres is the largest asteroid found in the Asteroid Belt, which is located between the orbits of Mars and Jupiter. Additional background reading can be found in the Unit 7 Appendix on the compact disk included with this curriculum see Solar System Lithographs: Visuals & Notes file. 3. Planet Activities (Order & Size) Review: Place Planets in Correct order Have students review the 8 planets and their order from the Sun. Only a preview of the images are printed in the curriculum. A full set of Lithographs are in the Unit 7 Appendix in three versions: Our Solar System Lithographs (Visuals & Notes) Original Our Solar System Lithographs (visuals only) Our Solar System Lithographs (Visuals & Notes) half page version Students can recite this mnemonic or make there own to memorize the planets order: My Very Excellent Mother Just Served Us Noodles Bonus Questions: See Unit 7 Appendix on compact disk for 1 page handout for students. They will need to view the full set of lithographs and notes (online at: http://www.soest.hawaii.edu/curriculum/tourthroughthesolarsystem/solar- System-Lithograph-complete-Set.pdf. No answer key is provided. Scale of the Planets Activity: Assign Object to Planet View the Scale in the Universe images (3 page handout printed in curriculum or show the 5 color slides see pdf document in Unit 7 on CD). Then give groups various objects (see table below) and ask them to place them on the Scale in the Universe Activity handout under the correct planet names. Discuss answers and share facts in table below with class. Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 3
Example of objects to use to represent relative Planet and Plutoid sizes http://www.parkland.edu/planetarium/guidesearch.html Object Diameter (miles) Scale Object Scale Object Scale Distance from Sun (inches) Sun 864,000 38-inch sphere grapefruit n/a Mercury 3,100 brass BB salt grain 3-1/8 Venus 7,550 marble raw sugar 6-3/4 Earth 7,927 marble raw sugar 9-1/4 Mars 4,200 1/4" bead salt 14-1/8 Jupiter 88,900 softball cherry 48-1/2 tomato Saturn 75,200 baseball green 89-1/4 grape Uranus 29,200 golf ball frozen pea 177-3/4 Neptune 28,000 ping pong ball frozen pea 279-3/4 Pluto 1,500 grain of sand speck of baking soda 367 4. Plot the Distance of the Planetary Objects Using the data table provided in the handout, have the students plot the distance of the planets in A.U. (Astronomical Unit) from the Sun. (1 A.U. = 149,598,000 km, the distance from the Earth to the Sun.) The goal is to be able to emphasize the distance between planetary objects, a common misconception is that the planets are equally spaced. It is good to have the students graph the distance between the planets by hand rather than in Excel so that they have to think about the scale that they are going to use and to see how great the distance is. The more advanced students can calculate the distances between planets, in A.U., themselves. Download graph paper from: http://incompetech.com/graphpaper/plain/. Select the grid size that works best for this activity, for example: Minimum border = 0.5 cm Grid line width = 0.5 points Grid spacing = 2 lines/cm Online Activity: Another way for the students to visual the distance between the planets can be seen at: http://www.bradley.edu/las/phy/astronomy/scale.html It is a tour of the Solar System with relative distance between each planet illustrated by scrolling between planets. Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 4
Plot the distance of the planetary objects exercise ANSWER KEY 1. How do the distances to the Sun compare for the inner (Mercury through Mars) versus the outer (Jupiter through Pluto) planetary objects? The distances between planetary objects are closer together for the terrestrial planets (Mercury through Mars) while the distances between Jupiter through Pluto are significantly larger (see the graph provided on the following page). 2. Between which two planets does the Solar System double in size? Saturn (9.5 AU) and Uranus (19.2 AU). The above figure is a graph of the distance from the Sun in A.U. versus the planetary object order, starting with Mercury, including the Earth s Moon, and ending with Pluto. The students graphs should resemble the plot above. Diamonds represent terrestrial planets; Mercury is blue/gray diamond, Venus is a royal blue diamond, Earth is a green diamond, and Mars is a red diamond. Circles represent gas giants; Jupiter is shown as an orange filled circle, Saturn is a pale yellow filled circle, Uranus is a cyan filled circle, and Neptune is a dark blue filled circle, Pluto is shown as a white square and the Earth s Moon is a gray triangle. Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 5
5. Extension Option: Order it Up Game (http://www.windows.ucar.edu/tour/link=/games/order_planets_intro.html) Alternatively, if the classroom has a computer with Internet access and a computer projector then the game, Order it Up can be projected onto the screen. "Order It Up" is a computer game about solar system statistics in which the players put planets in order on the basis of various statistics (i.e. mass, # of moons, etc.). Players must complete several puzzles to finish the game and scores are kept with a jumbled photo of a planet that un-jumbles as the player correctly places planets in order. The game gives the players 10 hints. It takes between 5 and 10 minutes for individuals to play. The individual puzzles (8-10 of them in random order) make good think-pair-share activities. For each list, give the student pairs 2 minutes to assemble a list. Then the class as a whole should direct the instructor to enter the answers into the applet and decide whether to go for a hint. Suggestions for use: Use this web page as a study guide In class as a game that 2 people or 2 groups of students can compete against each other. Ka Hana Imi Na auao A Science Careers Curriculum Resource Go to: www.cds.hawaii.edu/kahana 6