Solar System Showcase

How far away is Pluto?

Our solar system is truly enormous. Developing a sense of just how enormous is difficult, however. A good starting point to this understanding is to have children explore the relative distances across our solar system, and this game provides a fun way to do that. This is also a great activity for learning about the major bodies in our solar system, and to practice measuring and estimating.

Preparation

You will need a room at least 40 feet long for this game, and ideally 9-10 children. This activity is scalable – you could do it outside at a distance of 40 meters or yards instead, or at any measurement, really – you’ll just need to recalculate the measurements included in these instructions.

Print the planet images or create the name cards for each planet mentioned under “Suggested Materials” (see list of planets under “Make it Matter”). Tape the image of the Sun (or the printed word “Sun”) on one wall of the room you are in. If you are outside, tape to any appropriate object, or even place on the ground. Place the photo of Pluto 40 feet away (or farther, if you are changing the scale), on the ground or taped to a wall. Create a 40’ measuring line on the floor with masking tape or string, and mark 1-foot lines along its length, starting at Pluto and ending at the Sun. This will make measurement during the activity much easier for you.

NOTE: For an indoor, and smaller-scale (though slightly more involved) version of this activity, try the Astro Map activity from this curriculum (click here).

Resources

Figure 1

Suggested Materials

Printed Solar System images from NASA Inspirations (click here) of the Sun, each of the major planets, and Pluto and Ceres (the two largest dwarf planets), or 11 sheets of paper, each with a name of the Sun or a planet, large enough for people to read across the room.
Measuring tape
Masking tape

Optional Materials

A sesame seed or grain of rice.

Opening Discussion

Ask your students to name any planets in our solar system they can. Write down their list on chart paper or a dry erase board, and add anything they missed (use the list below for reference), including Ceres, the largest dwarf planet in the Asteroid Belt, and Pluto, also a dwarf planet:

Sun
Mercury
Venus
Earth
Mars
Ceres (the largest object in the Asteroid Belt)
Jupiter
Saturn
Uranus
Neptune
Pluto

Can they place these objects in order? Help them create a list in the correct order (above), and write this list down in a visible spot. How far apart do they think these objects might be? Show your students the NASA images of some of these objects included with this curriculum. You can print them out or show them the images on a computer. You can also visit NASA’s amazing solar system website, which is full of images, information and more: http://solarsystem.nasa.gov/planets.

The Challenge

Play this game by predicting how far apart the major objects in our solar system are!

Doing the Activity

Point out the “Sun” and “Pluto” signs you put up, and tell your students that you have created a scale model of the solar system, but you need help filling in the rest of the planets. Tell the group that you’d like to play a game where they predict how far apart the planets in our solar system are.
For a sense of scale, pass around a sesame seed or grain of rice, and tell students that it represents the size of the Sun in the solar system model you have created. NOTE: A sesame seed is about 3mm wide; a grain of rice is slightly thicker than that. If you scale this activity up (to 40 yards, for instance) your sample object will have to change as well. See “Suggestions” for scaling ideas.
Ask the group to gather at Pluto.
Refer to your list of planets and dwarf planets, and ask your students which planet is next closest to the Sun, after Pluto (Neptune). Ask the group to walk toward the Sun, and for each child to stop walking and stand where they think Neptune would be located in this scale solar system model. Hand the student closest to 9’ from Pluto the Neptune sign, and ask them to stay there and be Neptune (if you have fewer than 9 students, you can simply place the planet signs at each stop and all continue on together).
Have the rest of the group walk and predict where the next planet, Uranus, would be (20’ from Pluto). Give the closest student the Uranus sign, and have them stay there.
Continue in this manner with the remaining planets. When you reach Ceres…things start to get a little tight! You’ll need to break out the measuring tape to start measuring inches, and you’ll likely have to just choose a student for each planet, as your students will all be in around the same area.
Here are the planet distances in two measurements – the first column is how many feet and inches apart the planets are in our 40-foot solar system. Please note these are approximate distances – a good deal of rounding up or down has occurred, for the sake of simplicity. The second column is how far each planet actually is from the Sun in Astronomical Units (AU) – one AU is the average distance between the Earth and Sun (about 150 million kilometers, or 93 million miles):

Object	Distance from Pluto in the 40’ Scale Model	Actual Distance from Sun (in Astronomical Units, or AU)
Pluto	0'	39.4
Neptune	9'	30.1
Uranus	20'	19.2
Saturn	30'	9,54
Jupiter	34'	5.20
Ceres	37' 3"	2.77
Mars	38' 5"	1.52
Earth	39'	1.0
Venus	39' 3"	.72
Mercury	39' 7"	.39
Sun	40'	0

And see Figure 1 in Resources, above, for an overhead view of the distances.

Let’s Talk About It

Ask your students if they were surprised by the results. It is worth reinforcing the vast distances between objects in our solar system – while it may look like they are close together, based on this activity, our solar system is a truly enormous place. Ask your students how long they think it might take to drive in a car, at 60 miles per hour, from Earth to Mars (using the average distance between the two). Write everyone’s guesses down on a piece of chart paper, dry erase board, etc. Did anyone come close? Reveal the answer: Traveling from Earth to Mars at 60 mph would take 92 years (it’s 48,500,000 miles)!

Keep in mind this is non-stop travel. No bathroom breaks! Ask students to share the longest road trips they have ever taken. Can they imagine extending those trips to 92 years, or even almost 6 months? How long do they think it would take to travel in a car (or spaceship), at 60 mph, to the other major pit stops in our solar system? You can figure this out by dividing the distance between Earth and any object by 525,600 (the number of minutes in a year, since 60 mph = 1 mile per minute). If you are working with older children, you can give them this challenge – either share with them the average mileage listed below, or even have them research those distances on line. Then, have them calculate travel time by dividing the distance by 525,600. With younger children, you can have them guess travel times (now that they have some context with the three times above). Here are some distances from Earth (rounded) and 60 mph travel times:

Earth to The Sun – 93,000,000 miles (177 years)
Earth to Mercury – 57,000,000 miles (108.5 years)
Earth to Venus – 26,000,000 miles (49.5 years)
Earth to The Moon – 239,000 miles (5.5 months)
Earth to the Asteroid Belt – 111,500,000 miles (212 years)
Earth to Jupiter – 390,000,000 miles (742 years)
Earth to Saturn – 792,000,000 miles (1,507 years)
Earth to Uranus – 1,692,500,000 miles (3,220 years)
Earth to Neptune – 2,704,000,000 miles (5,145 years)
Earth to Pluto – 3,637,000,000 miles (6,920 years)

What do they think is in all that space between the planets/other objects (hint – we call it “space” for a reason…)? There is not a lot out there in space. The majority of the universe is wide-open and empty.

Build On What They Talked About

If you’d like to continue on past our solar system, you can ask your students to predict how far away, in the 40-foot model you created, the next closest star would be to our solar system (our closest star is, of course, the Sun). The closest star outside our solar system is called Proxima Centauri, and it is about 4.2 light years away – that’s almost 25 TRILLION miles. This is a distance that’s pretty much impossible to imagine. At 60 miles per hour, it would take over 47 million years to drive there. And in our 40-foot solar system model, Proxima Centauri would be 271,000 feet, or 51 miles away. Look on a map at how far 51 miles is from where you are.

Suggestions

This activity can be even more impressive if you can do it on a larger scale. If you are near a football field, for example, you could use the existing yard markers to help out. In this instance, start from the Sun instead of Pluto, and use the AU measurements above, calculating them as feet. Here are some measurements if you try this on different scales:
- 40-yard scale – the AU numbers in the chart above equal how many yards each object is from the Sun in a 40-yard model. You could also measure in feet by multiplying the AU numbers in the chart above by 3. For example, Mercury, your new first stop, would now be 1.17 feet (.39 yards) from the Sun, instead of around 5 inches, as it was in the 40-foot model. Pluto is 118 feet (39.4 yards) away from the Sun. Your example “Sun”, showing a sense of scale, should be something about 9mm in diameter, or a little less than 3/8 of an inch…about the size of an un-popped popcorn kernel.
- 100-yard scale – stick with yards, and multiply all AU numbers in the chart above by 2.5. For example, Mercury, your new first stop, would now be .975 yards from the Sun (you can round up to 1 yard), instead of around 5 inches, as it was in the 40-foot model. Pluto is 98.5 yards away from the Sun in this model. Your example “Sun”, showing a sense of scale, should be something about 23mm in diameter, or slightly less than one inch…about the size of a quarter.
For an indoor, and smaller-scale (and slightly more involved) version of this activity, try Astro Map from this curriculum (click here).
You could make similar relative distance maps of cities in the U.S., countries, streets in your town, etc.

Earth and Space science activities were developed with the support of NASA. This material is based upon work supported by NASA under grant award number NNX14AQ83G. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration (NASA).