Explore! Jupiter's Family Secrets

Jump to Jupiter


Children ages 8 to 13 help create and then navigate an outdoor course of the traditional "planets" (including dwarf planet Pluto), which are represented by small common objects. By counting the jumps needed to reach each object, children experience firsthand the vast scale of our solar system. The children's posters from Jump Start: Jupiter! may be used to construct the course.

Participants taking part in activitiy

What's the Point?

  • The solar system is a family of eight planets, an asteroid belt, several dwarf planets, and numerous small bodies such as comets in orbit around the Sun.
  • The four inner terrestrial planets are small compared to the four outer giant planets.
  • Planets have some similarities and many differences.
  • The distance between planetary orbits is large compared to their sizes.
  • Models can help us comprehend large-scale spatial relationships.


For each group of 20 to 30 children:

  • Measuring tape
  • 1 softball or grapefruit
  • 3 pepper flakes, each attached to a (3"x5") card
  • 2 poppy seeds, each attached to a (3"x5") card
  • 2 (1/2" or so) marbles, one slightly smaller than the other, each attached to a (3"x5") cards
  • 2 peppercorns, each attached to a (3"x5") card
  • 1 meter- or yard-stick
  • Optional: 1 set of Our Solar System lithographs (NASA educational product number LS-2013-07-003-HQ) or 1 set of 11x17 LPI Solar System Posters
  • Optional: 1 set of children's posters about solar system objects from the activity Jump Start: Jupiter!
  • 12 (3') stakes to attach to the planet lithographs or children's posters
  • Mallet or heavy object (for placing stakes in the ground)
  • Tape
  • A large outdoor area

For each child:

For the facilitator:


  • Review the complete background information.
  • Determine how many planets your space accommodates before you start.A football field, for example, would contain the entire model out to the orbit of the dwarf planet Pluto if the course doubles back on itself six times. You do not have to use all the planets! You may be able to modify the course to fit inside by halving the scale (of planets and distances) or by using only the inner planets. The activity works best if the planets from Mercury to Jupiter are included to illustrate the scale of our solar system. If you must omit some of the solar system objects, provide a wall or other area to display the Our Solar System lithographs or Jump Start: Jupiter! posters about those that cannot be represented in the course.
  • Set up a solar system course in an outside area or in a long hallway. Mark each object's position with a stake. Jump to Jupiter: Planet Sizes and Distances provides the appropriate distances.
  • Alternatively, create your own larger or smaller course. Use the Exploratorium museum's online calculator to automatically determine the scaled sizes of the planets and distances from the Sun, relative to the size of the Sun you provide. A larger course will make the planet representatives larger and easier to see. A smaller course may fit in tighter location, or even indoors, but the Pluto, Mercury, and Mars representatives quickly become too tiny to see with the naked eye as the course is scaled down.
  • Attach the children's Jump Start: Jupiter posters or the Our Solar System lithographs to the appropriate stakes.
  • Optional: You may want to have an adult present at each stake in the course as the distances may be quite large. Additional adults also can guide the children with questions and information and keep them moving to other planets.


1. Explain that the children will be creating a scale model of the solar system.

  • What's a model?

We use models to help us represent objects and systems so that we can study and understand them more easily. By "a scale model" in this case, we mean a model that has smaller parts but parts that are relatively the same size and distance to each other as the real planets, dwarf planets, asteroid belt, and Sun.

  • Are all the planets the same size? No!
  • What about distance from the Sun? Are the planets all the same distance from the Sun? No.
  • What are some of the objects in the solar system? Starting with those closest to the Sun, there is Mercury, Venus, Earth, Mars, the asteroid belt, Jupiter, Saturn, Uranus, Neptune, and the dwarf planet Pluto.

2. Present the items you have selected to represent the planets, Pluto, and asteroid belt and ask them to identify which one is the appropriate size for their solar system object. Invite volunteers to come forward and appropriately label the cards with the solar system objects' names as they are identified.

  • Which item would represent the Sun? Softball or grapefruit.
  • How big would Earth be? About the size of a poppy seed or dessert sprinkle — 1/100 the size of the Sun.
  • How about Jupiter? Mercury and the dwarf planet Pluto? Jupiter would be about the size of a large marble — 1/10 of the size of the Sun. Mercury and Pluto would be very tiny pepper flakes — just specs — in this model!

3. Have the volunteers line up in the order of the planets from their distance from the Sun.

  • If you are going to make an accurate model of the solar system, what things might you consider? How far apart would the objects need to be placed?

Explain that their objects are 10 billion times smaller than the actual planets! Even so, an entire large yard or football field would be required to hold this model of the solar system out to the orbit of the dwarf planet Pluto.

Facilitator's Note: You may wish to have older children calculate the scale of this solar system model for themselves. Provide the children with the solar system objects' actual sizes and distances from the Sun, which is summarized in Family Portrait...in Numbers. After dividing the figures by 10 billion, the children may wish to convert them to more commonly used units. The following conversion factors may be helpful:

1 yard = 36 inches
1 meter = 39.37 inches
1 mile = 5280 feet
1 inch = 2.54 centimeters
1 kilometer = 0.62 miles

4. Have the children navigate the solar system course!
Distribute Journals or the "Jump to Jupiter" pages and pencils or pens. Ask the children to count and record the total number of (one-meter) jumps from the Sun it takes to get to each marker. Provide the meter- or yard-stick for the children to practice jumping that length.

5. Guide the children as they discover distance, size, and interesting facts about a solar system object at each stake. Ask the children to start counting with the number at which they left off (i.e., count six jumps to Mercury, then count from six until they reach Venus at eleven jumps, etc.). Have them note the size of each marker representing a planet.

  • How many hops from the Sun is the planet, asteroid belt, or Pluto?
  • How big does the softball "Sun" look from here? Imagine what the real Sun would look like in the sky of this solar system object!
  • What do you think is happening to the temperature as they travel further away from the Sun? It's getting colder!


  • Did you miss running into an asteroid between Mars and Jupiter?
  • Are the planets in a straight line, as they are in our model? No!

Remind the children that the planets are in motion as they orbit the Sun. Only rarely do several planets "line up." Have them imagine the circles that each planet would trace! Or, if desired, invite a few children to carry a selection of planet models in large circles around the "Sun" to demonstrate their orbits.

Facilitator's Note: One common misconception among children is that the planets are often, or even occasionally, lined up in a row. Those planets closest to the Sun — Mercury and Venus — orbit faster than Earth and do frequently line up with the Earth and with each other, but it takes many hundreds of years for distant giant planets like Uranus and Neptune to line up with each other. Chances are that in the entire history of our solar system, the planets have never all been lined up.

  • Which was the largest planet in our solar system model? Jupiter.
  • What were the smallest objects in our solar system model? Even the largest asteroid in the asteroid belt, Ceres, is just a speck of dust. Pluto, Mercury, and Mars are all tiny pepper flakes.
  • What did you notice about the distances from the Sun to the inner planets versus the distance to the outer planets? The inner terrestrial planets — Earth, Mercury, Mars, and Venus — are much closer together. The giant planets get farther and farther apart.
  • How long do you think it would it take a spacecraft to get to these other planets? Accept all answers before providing more information.

Part of this answer depends on the type of spacecraft and if it is doing other things like circling other planets. In general, if it was possible for a spacecraft to fly directly to Mercury, it would take it about 51/2 months to get to there if it was going in a straight shot. The MESSENGER spacecraft, launched in 2004, arrived at Mercury in 2011; MESSENGER had several flybys of other planets to help it slow down so that it was able to go into orbit around Mercury. New Horizons, launched in 2006, is expected to reach the dwarf planet Pluto at the "other end" of our solar system in 2015! Due to a gravitational assist from Jupiter, New Horizon's trip has been shortened by three years.In 2016, the Juno spacecraft will arrive at Jupiter. Juno launched in 2011, and like MESSENGER, it will have a flyby that slings it past Earth (in 2013) on its way to the giant planet.

  • What do you think happens to the temperatures as you get farther from the Sun? In general, the greater the distance the colder the temperature!

Temperatures can reach a scalding 800°F (425°C) on Mercury and even warmer on Venus (850°F!) due to its thick atmosphere. After Earth's balmy –125 to 130°F (–87 to 54°C), the temperatures begin to plummet rapidly. It is –238°F (–150°C) on Jupiter, and afrigid –364°F (–220°C) on Pluto.

  • How far away — at the scale of the game — do you think the Alpha Centauri star system, the nearest stars (besides our Sun), is? Allow the children to guess before providing the answer: At this scale, Alpha Centauri would be slightly larger than a softball and about 2,500 miles (4,000 kilometers) away, roughly the distance between Los Angeles and New York City!

If possible, build on the children's knowledge by offering them a future Jupiter’s Family Secrets activity. Invite the children to return with their families to see the planets of our solar system for themselves in Planet Party.

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