Please jot down or ponder your answers. 1. What causes seasons. a Please jot down or ponder your answers. 1. What causes seasons? a. Earth is closer to the Sun in the summer and farther away in the winter b. something else 2. How can you tell the difference between planets and stars? a. planets are brighter b. something else 3. What causes Moon phases? a. Earth’s shadow b. something else 4.What is Pluto? 5. What’s the difference between the Solar System and the Milky Way? How many stars are in each?

Sally Brummel, Planetarium Coordinator, Bell Museum of Natural History Explore the Universe: Astronomy Activities for the Classroom and Beyond Sally Brummel, Planetarium Coordinator, Bell Museum of Natural History sbrummel@umn.edu 612-624-8146

Today's Goals: 1. To give you background knowledge of astronomy so you are confident in presenting the content and answering questions. 2. To demonstrate activities related to astronomical misconceptions and other topics.

ExploraDome At your school At the Bell Museum The ExploraDome is a portable, immersive learning environment where students experience "hands-on, minds-on" learning. The ExploraDome programs feature age-appropriate lessons delivered underneath a 25-foot diameter dome at your school or a 12-foot diameter dome at the Bell Museum. Through guided inquiry, based on the Minnesota State Science Standards, students can virtually travel from inside of the subatomic realm to the edge of the known universe! This system is the first portable dome in the world built around the dynamic scaling software known as Uniview. The ExploraDome program inspires minds and leaves a lasting impression on students.

Please jot down or ponder your answers. 1. What causes seasons. a Please jot down or ponder your answers. 1. What causes seasons? a. Earth is closer to the Sun in the summer and farther away in the winter b. something else 2. How can you tell the difference between planets and stars? a. planets are brighter b. something else 3. What causes Moon phases? a. Earth’s shadow b. something else 4.What is Pluto? 5. What’s the difference between the Solar System and the Milky Way? How many stars are in each? These may sound silly, but it’s meant to challenge you. Those are common misconceptions, and I’ve found that most people know those *aren’t* the reasons, but can’t explain what the real reasons were. So I didn’t want to put the correct answers in writing! Life is not a multiple choice test. It’s better to have the knowledge and be able to explain than to pick the answer from the list.

Life is not a multiple choice test!

Standard 3.3.3.1 Sun and Moon Observe and describe the daily and seasonal changes in the position of the sun and compare observations. Recognize the pattern of apparent changes in the moon's shape and position. Standard 3.3.3.2 Solar System Demonstrate how a large light source at a great distance looks like a small light that is much closer. For example: Car headlights at a distance look small compared to when they are close. Recognize that the Earth is one of several planets that orbit the sun, and that the moon orbits the Earth. Standard 8.3.3.1 Sun and Solar System Recognize that the sun is a medium sized star, one of billions of stars in the Milky Way galaxy, and the closest star to Earth. Use the predictable motions of the Earth around its own axis and around the sun, and of the moon around the Earth, to explain day length, the phases of the moon, and eclipses. Compare and contrast the sizes, locations, and compositions of the planets and moons in our solar system. Standard 9.3.3.2 Solar System Describe how the solar system formed from a nebular cloud of dust and gas 4.6 billion years ago. Compare and contrast the environmental conditions that make life possible on Earth with conditions found on the other planets and moons of our solar system The ExploraDome’s programs are based on the 2009 MN science standards. Here are some select standards for various grades. Third grade is the earliest that astronomy appears in the standards.

1. What causes seasons? a. Earth is closer to the Sun in the summer and farther away in the winter b. something else Earth is tilted toward the Sun in a hemisphere’s summer and away from the Sun in the winter. The higher Sun produces more direct sunlight, which concentrates the energy and heats more efficiently. A way to demonstrate this with a flashlight: shine it directly on your white/blackboard and trace the lit-up area. Then hold it at the same angle but tilt it and do the same. The light from the flashlight while tilted has to cover a larger area so each individual point gets less light, or fewer photons.

Planets do not twinkle, and move among the fixed stars. 2. How can you tell the difference between planets and stars? a. planets are brighter b. something else Planets do not twinkle, and move among the fixed stars. Learning to distinguish the difference between planets and stars takes commitment. Planets look like stars but from night to night “wander” among them. (In fact, “planet” comes from a term that means to wander. To ancient stargazers, the wanderers were Mercury, Venus, Mars, Jupiter, Saturn, the Sun and the Moon. ) Jupiter and Venus are brighter than any star, but Mercury, Mars, and Saturn have some stars that outshine them. A good description of why planets do not twinkle: http://earthsky.org/space/why-dont-planets-twinkle-as-stars-do You must get to know the stars and constellations, and be able to recognize an object that isn’t in the same place as it was the night before. A good way to start is by using a skymap for a few months as a guide to see how the planet positions change. Advanced learners may go on to predicting where and when they will see planets. Free skymaps are at: http://www.skymaps.com/ skymaps.com

3. What causes Moon phases? a. Earth’s shadow b. something else As the Moon orbits Earth, we see different views of the Moon's sunlit side. Here is an activity using models of Earth, Moon, and Sun to discover what causes Moon phases. http://www.learner.org/teacherslab/pup/act_moonphaseintro.html

Moon Phase Activity Kinesthetic method If your head is Earth with your nose as a mountain and the flashlight is the Sun, stand so it is noon on "Mt. Nose." (directly facing light) Stand so it is midnight. (facing directly away) Stand so it is sunrise. (left shoulder pointed toward light) Rotate until it is sunset. (half turn counterclockwise) Add the Moon into the demonstration. Using the Moon graphic as a guide, determine where in the Moon's orbit each phase occurs. This activity demonstrates: Half of the Moon is always lit by the Sun, but you can only see the portion of sunlit side that is facing you. You cannot see every phase at any time during the day.

Moon Phase Activity Kinesthetic method

4. What is Pluto? Most popular answer: Not a planet Second most popular answer: A dwarf planet What is a dwarf planet?

What is a dwarf planet? Dwarf planets are round like planets. And they are smaller. But the space around them is full of similar small objects. The space around planets is mostly empty. Dwarf planets can be in either the Asteroid belt or the Kuiper belt. Asteroids are made of rock and metal, Kuiper belt objects are made of ice and rock. This is a good topic for emphasizing that science is a process, a way of understanding our universe, instead of a body of facts. Knowing what something “is” or “isn’t” is not useful if you do no know how scientists came up with the definitions. The story of Pluto is analogous to the story of the discovery of asteroids, which took place around 1800. Astronomers discovered a new object orbiting the Sun and categorized it as a planet. They named it Ceres. Then they discovered another. And another. Within a few decades they had discovered dozens, and they realized they had discovered a new category of objects. Some astronomers knew this right away and termed them asteroids, meaning “star-like.” It took about 50 years for everyone to agree that they were not planets. Pluto was discovered in 1930 and deemed a planet. Soon after, astronomers suggested the existence of a population of objects beyond Neptune akin to the asteroid belt. One of them was Gerard Kuiper (“KI-per”) and the theoretical belt was named after him. The next Kuiper belt object (KBO) was discovered 62 years later, in 1992. Today there are over 1000 KBOs known, and there are likely hundreds of thousands of them. The first one bigger than Pluto was discovered in 2005, named Eris. This was briefly known as the “10th planet” until astronomers came up with the official definition.

5. What’s the difference between the Solar System and the Milky Way 5. What’s the difference between the Solar System and the Milky Way? How many stars are in each? The Solar System is the collection of the Sun and all the objects that orbit it. The Sun is one of the stars in the Milky way. The Milky Way is a galaxy, which is a collection of 400 billion stars, along with gas and dust. We know of hundreds of other solar systems in our galaxy: stars beyond our Sun that have planets. It’s hard for many students to realize that there is only one star in the solar system: the Sun. They know the Sun is a star, but the distinction of “solar system” vs. “galaxy” is hard to comprehend. A good way to describe it is: “Your city is one of many that make up the state of Minnesota. Our Solar System is one of many that make up the Milky Way Galaxy.”

Earth-Moon Scale Of the following objects, which two best represent the Earth-Moon size comparison: Basketball Golf ball Tennis ball Marble Soccer ball How far apart should the two balls be?

Earth-Moon Scale Of the following objects, which two best represent the Earth-Moon size comparison: Basketball Golf ball Tennis ball Marble Soccer ball How far apart should the two balls be? Wrap string around basketball 10 times, about 30x diameter of the Earth. The scale of the Earth and Moon is easier to visualize/demonstrate, but still suffers from initial misconception. If students hold misconceptions about distances, they may have difficulty discarding the belief that Earth's shadow causes the phases of the Moon. Beginning with an investigation of the Moon's distance from Earth helps students understand later that half of the Moon's surface is always lit.

Scale Model Solar System Approximation method Using an arm’s length of register tape, each student will illustrate the relative distances between the orbits of the planets. 1. Write “Sun” on one end of the paper strip and “Pluto” on the other end. 2. Fold the tape in half; this is Uranus. Label the strip. 4. Fold Pluto to Uranus; this is Neptune. 5. Fold the Sun to Uranus; this is Saturn. 6. Fold the Sun to Saturn; this is Jupiter. 7. Fold the Sun to Jupiter; this is the Asteroid Belt. 8. Fold the Sun to Asteroid Belt; this is Mars. 9. Fold the Sun to Mars; this is Venus. 10. Write Mercury between Sun and Venus. 11. What is missing? Write Earth between Venus and Mars. One of the most difficult concepts for students, and adults, is the sense of scale in the solar system: how the sizes of the planets compare to each other, how much distance is between each object, and especially how these two compare. Here are a variety of methods for demonstrating this concept. From “Pocket Solar System,” developed by the Astronomical Society of the Pacific. http://www.astrosociety.org/education/astro/bayarea/PocketSolarSystem.pdf

Scale Model Solar System Approximation method For younger students: do the activity without introducing distance and units. For older students: introduce the distance measurement of “Astronomical Unit” and the idea of approximation. At this scale, the Sun would be less than 3 millimeters, and the planets would be undetectable.

Scale Model Solar System Kinesthetic method Divide students into groups of at least 8 and assign each a solar system object. (Objects in italics are optional) Have each pace off the number of steps corresponding to their objects in a place such as a gym, football field, playground, etc. Each step = 1 meter Sun: start Mercury: 1 step Venus: 2 steps Earth: 2.5 steps Mars: 4 steps Asteroid belt: 8 steps Jupiter: 13 steps Saturn: 24 steps Uranus: 49 steps Neptune: 76 steps Kuiper belt: 100 steps From National Geographic Education http://education.nationalgeographic.com/education/activity/planetary-size-and-distance-comparison/?ar_a=1

Scale Model Solar System Kinesthetic method For younger students: instead of requiring each step to equal 1 meter, you can use one student’s step size as long as he/she keeps consistent. This demonstrates the idea of relative scale. For older students: calculate the scale to fit the area in which your class will model the solar system. At this scale the sun would be 1.3 cm (.5 inches) in diameter, Jupiter would be just over a mm and the rest of the planets barely detectable.

Scale Model Solar System Web demonstrations http://www.scalesolarsystem.66ghz.com/ http://www.davidjarvis.ca/dave/gallery/lg/star-sizes.jpg 1. This is the closest method I’ve seen that allows for visible representations of both size and distance. 2. Comparing planet sizes and expanding to comparisons with stars

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