<p>Do these if you have more than 45 minutes or if you have extra time at the end.</p><p>Note: To save time, estimate the average weight and age of the class and just use that. You probably don’t need to go through every single planet – just pick a couple extreme ones to get the point across – then move on to the fun part!</p><p>How Much Do You Weigh? Purpose To understand that weight is a measure of gravitational attraction and that this force is not the same on each planet.</p><p>Background Gravity is a universal, natural force that attracts objects to each other. Gravity is the pull toward the center of an object; let's say, of a planet or a moon. When you weigh yourself, you are measuring the amount of gravitational attraction exerted on you by Earth. The Moon has a weaker gravitational attraction than Earth. In fact, the Moon's gravity is only 1/6 of Earth's gravity. So, you would weigh less on the Moon. How much would you weigh on the Moon and on the other planets? </p><p>Procedure 1. Write your weight (or an estimate) on the board. 2. Pick a planet and multiply your weight by the number given in the "New" Weight Chart. Example for the Moon - for a person weighing 60 pounds on Earth: 60 x 0.17 = 10.2 A 60 pound person would weigh 10.2 pounds on the Moon! </p><p>"New" Weight Chart</p><p>Planet Multiply your Earth weight by: Mercury 0.4 Venus 0.9 Earth 1 Moon 0.17 Mars 0.4 Jupiter 2.5 Saturn 1.1 Uranus 0.8 Neptune 1.2 Sun 28</p><p>How Old Are You? Purpose To understand the relationship between planetary orbits around the Sun and our measure of time. </p><p>Background Your birthday is actually a celebration of a trip made by Earth around the Sun one time. For each trip around our star we "age" one year... or at least that is how we humans express it. How "old" are you on the other eight planets in our solar system? </p><p>Procedure 1. Figure your age in Earth days. [your age x 365] *Use the class average 2. For the terrestrial planets, divide your age in Earth days by the number of Earth days in a planet's year. The answer is your "new" age. Example for Mercury - for a person 20 years old on Earth: 20 x 365 = 7300 Earth days old 7300 / 88 (Earth days in Mercury's year) = 83 The 20 Earth-year-old person would be 83 years old on Mercury! 3. For the outer planets, find the number of Earth days in each planet's year. Then divide your age in days by the number of Earth days in that planet's year. The answer is your "new" age. Example for Jupiter - for a person 20 years old on Earth: 20 x 365 = 7300 Earth days old 12 Earth years x 365 Earth days/year = 4380 Earth days in one Jupiter year. 7300 / 4380 = 1.7 The 20 Earth-year-old person would be 1.7 years old on Jupiter! </p><p>"New" Age Chart</p><p>Terrestrial Planets Approximate length of year: Mercury 88 Earth days Venus 225 Earth days Earth 365 Earth days Mars 687 Earth days Outer Planets Approximate length of year: Jupiter 12 Earth years Saturn 29.5 Earth years Uranus 84 Earth years Neptune 165 Earth years</p>