The Solar System Ballet, a learning activity for kids of all ages ----------------------------------------------------------------- 1. Objective: To learn about the planets, their motions, their distances and their individual characteristics. 2. Prep Work: Grades K-5: none Grades 6+ : hopefully some basic geometry and algebra (it makes the exercise more meaningful with it, but it can be done without it) 3. Equipment: computer/laptop LCD Projector screen models of the planets (styrofoam balls or beachball models) strong flash light labels for the planets industrial size (25ft+) tape measure blank paper pencils planet distances chart + copies planet sizes chart + copies some empty space in the class room (or go outside) 4. Instructions see main text 5. Assessment a. before I usually ask them if they know the names of the planets, possibly in order (most of them do). b. afterwards one could ask more details, how do the planets and moons move, how are the first four different from the second four, how do I know the Earth is round? The older ones should describe it in words, the little ones in pictures (and I get loads of those after many classes). To teach people about our Solar System can be revealing and rewarding, for the students and the teacher. Especially the little ones care not so much about the finer details, but getting to orbit is fun. The issue with little ones (and some bigger ones too) is that they cannot yet grasp theoretical ideas purely with their minds. If you can show them a video, that's better, but if they are able to learn it with their bodies, essentially being what they learn about, they will understand and remember it much more easily. And, as I have discovered, they will also enthusiastically tell everyone else about it (even though grandma may not be too keen on being the fast-moving comet). There are three segments to this, they can be done together or separately, one, two, or all three, depending on time limits and age of the students. FIRST SEGMENT (any age) I usually start out by talking story about the planets (here in Hawaii talking story is an important part of life). I show pictures of the planets (more detail for grades 4+, less for the little ones), and relate the appearance and environment of each planet to things they know from the Earth/Moon system. First, look at the whole collection and see the difference between the first four (little rocky ones) and the second four (gas giants). See the sun to scale, and see a picture of all the planets lined up nose-to-nose three times and still not fill the diameter of the sun. Mercury: small, rocky, hot, lots of craters, looks like the Moon. Venus: cloudy, 90 atmospheres (give diving rule of 33ft/1atm, make the older ones do the math, both ways)*, acid rain, volcanic soil (like Hawaiian cinder)**. * I tell them that the SCUBA rule is that you gain 1 atm. of pressure for every 33 ft you descend. So, at 99 ft you have how many atmospheres (4, most forget to add the one you start with). Then, for the older ones, after I tell them that Venus has 90 atm., I ask them how deep they would have to go down in the ocean to get that (89 atm * 33ft = 2937ft = .55 miles, over half a mile, way below the SCUBA limit of 300ft). ** Looking at a picture of a crater (one crater), I point out that Venus (or Earth or Mars for that matter) are not as riddled with craters as Mercury. How come? I usually get many theories on stuff burning up in the atmosphere, which is good. When they see the photos of the lava flows, the older ones usually get it. I make a point of comparing the appearance of the soil to the stuff we have here on the Big Island. Earth: I show one of the photos of Earth from Apollo, and have them figure out how this was taken (visualize the appearance of Earth from LEO (shuttle, station) and from further away with the help of balls (sports balls, styrofoam balls). And I usually throw in a geography question about which two continents we are looking at (Africa and Antarctica). Moon: Make them realize the difference in appearance to Mercury (the maria, lava lakes, just like in Hawaii). And now they see the difference between ground that has been covered with lava, and ground that hasn't, side-by-side. Mars: volcanic soil (like Hawaiian cinder), sand storms, same inclined axis => seasons, Olympus Mons (vs. Everest and Mauna Kea), Vallis Marineris (about as long as the US is wide). Again I make a point of comparing the appearance of the soil to the stuff we have here on the Big Island. For classes engaged in robotics and/or space habitat exercises, I point out climatic and soil conditions, and ask questions about how they would prepare for that. [skip the asteroids unless they ask] Jupiter: the biggest one (about 1000x Earth, about 1/1000 of Sun, make the older ones do the math), gas giant, red spot, storms, weather, 4 Galilean moons (63 total, one student was ready to recruit two other classes to get the whole system together). Show picture of Io with volcanoes (the little ones get a kick out of a description of the smell). For the older ones show a picture of Europa's cracked ice surface and the potential promises underneath. Saturn: the rings (point out that the other gas giant have rings as well, just smaller). I always add a painting of what it look like to fly through the rings, it visualizes best that these are separate particles orbiting. Titan (atmosphere, lakes), ~60 more moons. Uranus and Neptune: weathern patterns, blue methane. Triton and its geysers (compare to Yellowstone). 27 and 13 moons. Pluto: for the older ones I get into the discussion as to why it got kicked out of the family. Horizons Mission is on the way. 4 moons. Comets: dirty snowballs (if time and outside space, do the shave-ice and hair-dryer experiment after the orbiting). Point out the two tails, and that the gas tail always points away from the sun. Ok, now that they know a little bit about the planets, it's time to orbit. I ask for a volunteer to be the sun (for the little ones I ask the teacher). Rarely is there room to do the whole Solar System at once, so I do it one planet at a time. Each volunteer gets to hold a model of their subject. Then I ask for a Mercury volunteer. I ask the whole class "Mercury is what?" [answer: Mercury is a planet] "A planet does what?" [answer: A planet goes around the sun] And so Mercury does (I make sure it happens counter-clock-wise). Then I ask for a Venus volunteer. I ask the whole class "Venus is what?" [answer: Venus is a planet] "A planet does what?" [answer: A planet goes around the sun] And so Venus does (I make sure it happens counter-clock-wise). Then I ask for an Earth and a Moon volunteer. I ask the whole class "The Moon is what?" [answer: The Moon is a moon] "A moon does what?" [answer: A moon goes around the planet] And so the Moon does (I make sure it happens counter-clock-wise). "Earth is what?" [answer: Earth is a planet] "A planet does what?" [answer: A planet goes around the sun] And so Earth does (I make sure it happens counter-clock-wise, and that Earth doesn't leave the Moon behind). Then I ask for a Mars and a Phobos volunteer. I ask the whole class "Phobos is what?" [answer: Phobos is a moon] "A moon does what?" [answer: A moon goes around the planet] And so the moon does. "Mars is what?" [answer: Mars is a planet] "A planet does what?" [answer: A planet goes around the sun] And so Mars does (hopefully not losing Phobos). By now they see the pattern, and usually the whole class answers in a chorus. With the older ones (and/or big classes) I add more moons with the outer planets, making it a bit more challenging. I've had one fourth grade some years ago in a big gym, who managed to do the whole Solar System at once without getting the orbits mixed up. I wish I'd taped that... And if I have more students than planets and moons, I get the rest to do comet orbits (they love doing the slingshot). SECOND SEGMENT (grades 4+) I have the students take out a sheet of paper, put a spot on one side called "Sun", and another spot of the other side called "Pluto" (they get mad if you leave out Pluto, beware of angry 4th graders). Then I ask them to put in the rest of the planets (and I ask for volunteers to recite the sequence if some have forgotten). Usually they space them out pretty evenly. Then I show them a chart of the real distances of the planets from the Sun (in AU, which I explain). The third column shows Pluto at the classroom scale of 33ft. For middle school and up I make them do the math for the other 8 planets. First, we set up the equation for Earth together, solve it, and then the class gets divvied up in 7 groups to work on the others. I've had mixed results, some 6th graders go at it like greased lightning, some 9th graders look at me like I'm nuts having them do actual math. I take my cue from the teacher in these cases. For the younger ones I have a filled-out chart, high schoolers get no breaks. Then we get to work with the tape measure. I ask for 10 volunteers (1 sun, nine planets). The Sun stands at one end of the class room, and we measure out the positions of the planets. This activity can of course also be done outside on larger scales. It becomes clear that the planets are not evenly spaced. The inner Solar System is very crowded, while the outer planets have lots of space between them. How come? Nobody knows, yet. I mention the extra-solar systems discovered, and how they are all different. Lots more to be figured out by future researchers. The follow-up question is, "How big is the Sun on this scale?" Usually, even the adults think on scales of the size of the building. Point out that that means all the planets would be inside the sun, which is clearly (and fortunately) not the case. The anwer is 7mm (using the 33ft Pluto distance). I then point out that therefore even the biggest planet is smaller than a grain of sand on the beach. That usually gets me buggy eyed students. Yes, space is very large and very empty. The second follow-up question is, "How far away is the nearest star on this scale?" (Proxima Centauri at 4 ly). Guessing ensues. The answer (from Hilo) is in Waimea (~50 miles as the crow flies). With the older ones that often results in a discussion on travel to other stars and the inefficiency of emailing friends on other planets. I always happily indulge them. One could add another bit on doing the Solar System object sizes to scale, i.e. have the Sun be as high as the class room (10ft), and scale everything else accordingly. That would be a great homework assignment. THIRD SEGMENT Pt. A (grades 4+) This concentrates on historical measurements, using basic math (geometry and algebra). I ask for three volunteers (Sun, Earth, Moon), and have them repeat the orbiting exercise. Then I point out the two configurations where eclipses can happen. I use a flashlight on the students' heads if the class room is dark enough. Then I show a time-lapse photo of a lunar eclipse. "What shape is the shadow?" [answer: The shadow is round] "What shape is the object making the shadow?" [answer: The object is round] "Which object makes the shadow?" [answer: The Earth] Therefore, the Earth is round. I point out that this can be observed by anyone, with the naked eye, and that it was noticed many thousand years ago. If anyone asks why it needed to be discovered again so much later, I refer them to their history and/or politicial science classes (it is better to avoid getting into discussions about the church). For the younger ones, I use my flashlight on random objects around the classroom to illustrate the fact the the shadow always takes the shape of the object making the shadow. Pt. B (grades 6+) I show a map of Egypt and tell the story of Eratosthenes. I tell of his experiment setting up poles at each place to measure the shadow on the summer solstice. There is no shadow at Syene, but there is a 7-degree shadow at Alexandria. I show a graphic with the geometry setup, and ask for the geometry rule regarding opposite angles when a line bisects two parallels (and I am continuously dismayed at the lack of math knowledge of the middle and high schoolers). Sigh... Once that is set up and explained, I help them set up the equation for measuring the circumferences of the Earth. Once we have our result, I point out the power of very basic math. THE END