Hands-on Experiments for the entire family....

What You'll Need
 

1 - 2 x 2-foot (60 x 60 centimeter) wooden board or cardboard square

1 - 10 to 12-inch (25 to 30 centimeter) wooden stick, 1/4 to 1/2 inches (6 to 12 millimeters) in diameter

1 - tube of glue

1 - marker

During the course of the year, we all notice that the Sun appears at different places during the same time of the day. At 6 P.M. in July it's still sunny outside, while at 6 P.M. in January the Sun has already set. It's easy to notice difference over the course of months, but what about the difference over weeks or even days?

With this activity you can verify that the Sun appears in a different location at a specific time every day of the year with one exception. On March 21, the Vernal (spring) Equinox, and September 21, the Autumnal (fall) Equinox, you will find the Sun in exactly the same position in the sky.

1. Glue the wooden stick to the cardboard square so that it stands upright (as shown in the sketch below). To assure that the full shadow fits on the cardboard, you may want to glue the stick closer to one of the edges.

4. Repeat this daily or weekly at the exact same time each day.

5. Discuss your observations with your family. Ask them if they think that there are any days where the shadow will appear in the same place at the same exact time. Ask them if they think that there are places on the planet where the shadow would appear at the same place at the same time every day.

What's Going On
 

The cause of the change in the shadow's location (i.e. the location of the Sun) is the tilt of the Earth's axis which causes the Earth to face the Sun at an angle of 23 degrees. Depending on where the Earth is located in its orbit around the Sun determines the length of the day. Since the Earth's location around the Sun is changing continuously, so are the length of the days.

The only two days where the Sun's location matches at any time are March 21 (Vernal Equinox) and September 21 (Autumnal Equinox).

The only place on the Earth where the Sun's location matches everyday is on the equator.

If your family continued this experiment the whole year round and connected the dots of your markings, the picture would look as follows. (Note the point of intersection. That point is where March 21 and September 21 fall.)

What You'll Need
 

1 - sheet of cardboard

1 - sheet of white paper
 

1 - piece of aluminum foil approximately 1 x 1 -inch (3 x 3 centimeters).

1 - pin or sharp point

1 - roll of tape

1 - pair of scissors

1 - ruler

1 - candle

 

Finding the Size of the Sun and Moon

In this activity you'll learn how to build a simple pinhole viewer. This apparatus can be used to project images from a variety of light sources. When used to project an image of the Sun, the pinhole viewer can be used to determine the diameter of Sun.

1. Cut a square about 3/4 x 3/4-inch (2 x 2 centimeters) out of the center of the cardboard.

3. Using the pin or other sharp point, puncture the foil to produce a small hole. You now have a pinhole viewer.

E X P E R I M E N T     1

Viewing an Image of a Candle

2. Light the candle. 3. Turn out the lights in the room. 

4. Hold a white sheet of paper a few inches or centimeters away from the opposite side of the pinhole viewer. You should be able to see an image of the flame projected on the paper.

 E X P E R I M E N T     2
 

Measuring the Size of the Sun

1. Hold the pinhole viewer so that the light from the Sun passes through the hole and falls on a sheet of white paper held behind the hole. Try to make the distance between the pinhole and the paper as large as possible.

2. Using your ruler, measure:

a. The diameter of the image of the Sun on the paper =

b. The distance from the pinhole to the paper =

Note: The distance from the Earth to the Sun is approximately 93,000,000 miles (149,600,000 kilometers).

 E X P E R I M E N T     3
 

Measuring the Size of the Moon

What's Going On

The pinhole viewer you built can project a variety of light sources. More complex pinhole viewers and cameras use a dark chamber behind the pinhole. This allows for the projection of images from sources that are not as bright as the ones used in this exercise. In a basic way, this is how cameras work.

What You'll Need
 
1 - set of clue cards

 
1 - set of planet image cards
 
1 - glue stick
 
1 - pair scissors
 
1 - piece of construction paper
 

The Order of the Planets

Using the "clue cards" and printouts of the planets provided, you'll learn about the order of planets in our solar system.

What to Do

1. Cut out the planet images. You'll use them as a visual aid to figure out the order of the planets.

2.  Cut out and distribute one clue card to each family member or participant. Give two to some if there are more cards than family members. Inform each person that he/she is not allowed to show the clue cards to anyone else, but is allowed to read them aloud to the group as many times as necessary.

3.  Using the clues, see if your family can figure out the order of the planets.
4. Check your answer with the Planet Order List Chart. If your order is different, try to see where you might have gone wrong.

5. Construct the order of the planets using construction paper and the planet images.

What You'll Need
 

9 - pieces of paper
 

1 - roll of toilet paper
 

1 - ruler
 

1 - set of planet printouts (provided) or 1 compass to draw your own


1 - pair of scissors
 

1 - calculator
 

1 - long hallway or outdoor space of at least 110 feet (30.5 meters). You can make a partial model if your space is smaller.

1 - table with measures of planet radius and distance to the Sun relative to scale

The Size and Distance of the Planets

In this activity, you'll investigate the concepts of relative size and distance by creating a basic model of our solar system.

1. Cut out the planet printouts provided, or using the measurements in the table above, use your compass to draw circles on paper. Note that this activity uses two scales: one for the printouts and cut-outs (larger), and one for the distances between the planets (smaller). This is due to the enormous distances involved. The planet cut-outs would be too small to use in our scale model.
 

2. If you choose to draw your own circles, label each planet. Cut the circles out and use them as your planets.
 

3. Choose a point at one end of a hallway, large room, or outdoor space as the Sun and mark it as your starting point.
 

4. Without looking at the table, place each planet in order of the distance you think they are from the Sun. As a reference, use 22.4 inches (57 centimeters) for the distance between Earth and the Sun.

5. Using the table, measure the distances by rolling out the toilet paper. Mercury is 1.9 sheets relative to the Sun, Venus 3.6 sheets from the Sun, etc. See how well your family did at estimating the distances. Move the planets to their proper distances, and you've built a scale model of the solar system.

What's Going On

This activity helps demonstrate the immense scale of our solar system. The sizes of the planets vary greatly as do the distances between planets and their distance from the Sun. The size of the Sun at larger scale (which isn't included in printouts) would have been 76.7 inches (195 centimeters) in diameter (38.4 inches in radius).