Astronomy activities for Elementary students
1.  Begin by discussing the vastness of the universe. For example, tell students that light travels at the unimaginably fast speed of 300 million meters per second, and yet light takes years to travel to us from the stars and takes thousands or evenmillionsof years to travel the depths of space between galaxies. When we’re dealing with those kinds of distances, it’s no wonder that we often think of them as being beyond our grasp. One way to put these distances into perspective is to think of them as multiples of smallerscale distances. By putting these quantities in the context of a wellunderstood frame of reference, they begin to have more meaning.  
2.  Help students grasp our place in the enormous universe by reviewing your school’s “galactic address”—beginning with its street address and ending with its place in the universe. Discuss the different units of measurement that are used to describe distances in each part of the galactic address. Give students examples for each step, or have them use reference materials to provide their own examples. Review any unfamiliar units of measurement, such as lightyears and astronomical units. By thinking about their location on a small scale first and then moving out to a much larger scale, students begin to get a sense of how distance is measured at each scale.


3.  Explain that one way to put the enormous sizes and distances of space into perspective is to compare them to smaller scales that are easier to grasp. In this activity, students will convert distances and sizes in space to smaller units. To begin, distribute the Classroom Activity Sheet: Understanding Sizes and Distances in the Universe, and have students work in pairs to answer the questions.  
4.  To help students understand how to solve these problems, you may wish to do the following problem together as a class:
Problem: Using a scale in which a quarter represents Earth, what would the distance from Earth to the moon be? Solution: Three pieces of information are needed in order to determine this scale distance to the moon: the diameter of the quarter, Earth’s diameter, and the actual distance from Earth to the moon. Measuring the quarter reveals that it has a diameter of 1 inch. Earth’s diameter is about 8, 000 miles. The actual distance from Earth to the moon is an average of 240, 000 miles, although this distance can vary with the moon’s orbit around Earth. For these calculations, though, the average can be used. Now that we have these three pieces of information, we can find the fourth piece (the scale distance) by setting up the following ratio: This is equivalent to the statement “The diameter of a quarter is to Earth’s diameter as our scale distance is to the actual average Earthmoon distance.” Substituting what we know shows us that: Remember that it’s important to keep track of the units. If Earth’s diameter had been given in kilometers, it would be incorrect to use 240, 000 miles for the Earthmoon distance. We would need to convert that distance to kilometers, too. Because both diameters are given in miles, they cancel each other and can be crossed out of the equation. In this problem, we should expect our result to be in inches, the same unit as the quarter’s diameter. By multiplying both sides of the equation by 240, 000 miles to isolate, we find that d = (240, 000 miles) × (1 inch/8, 000 miles) = 30 inches So, at this scale, the distance between Earth and the moon would be 30 inches. 

5.  Before students start working on the problems, it may be useful to go over scientific notation, which is a helpful way to deal with large numbers. Use the following examples to illustrate the powers of 10:


6.  Have each pair of students solve the problems listed below, which also appear on the Classroom Activity Sheet: Understanding Sizes and Distances in the Universe. Also included for students are constants that provide helpful information to be used in scaling. Students must figure out which information is needed to solve each problem. Students can work with partners to solve the problems, but each student should fill out his or her own sheet. All the questions from the Classroom Activity Sheet and the answers are listed below. Questions on the Classroom Activity Sheet: Understanding Sizes and Distances in the Universe
If Earth were the size of a penny
Helpful Measurements
