Hi, I teach 8th grade science and I wanted to take my students outside onto the football field and have them represent the solar system. My questions are: If we go out to the field and make the earth the size of a marble, how big and how far away should the other planets and the sun be? I looked at solar system live and I will be able to place the planets from there, but I don't know how far apart they should be? Do you have any suggestions?

P.S. Our field is just a little bit larger than 2 football fields.

I worked out what a scale model of the solar system would look like with the Earth the size of a 1 cm marble, but I don't think it'll fit in your space! Here's what I got:

Object

Diameter (cm)

Distance from Sun (m)

Sun

109

--

Mercury

0.38

46

Venus

0.95

84

Earth

1.0

118 (387 ft)

Mars

0.53

178

Jupiter

11.2

610 (2000 ft)

Saturn

9.4

1120

Uranus

4.0

2250

Neptune

3.9

3530

Pluto

0.18

5800 (3.6 miles)

So, it doesn't look like this particular scale will work. To fit it on the space of two football fields, I think you will have to use something very small, like sand, or points on a piece of paper, for the smallest planets. I found a site that will calculate the scale model for you if you input the Sun size. I would just try putting in different sizes for the Sun and see if you can get something that will work for you.

Lynn uses radar astronomy to study the planets, especially Venus. She got her PhD in Astronomy from Cornell in Summer 2004 and is now working at the Smithsonian in Washington D.C. on the Mars Express radar.