Explore the Solar System here on Earth!

See how well you do at the following simple trivia questions:

1. How big is the Moon?
2. How big is the Earth?
3. How big is Jupiter?
4. How big is the Sun?
5. How big is Pluto?
   
6. How far is the Moon from the Earth?
7. How far the Earth is from the Sun?
8. How far is Jupiter from the Sun?
9. How far is Pluto from the Sun?
   

Give up? Here are the answers:

1. The Moon is 2160 miles in diameter
2. The Earth is 7926 miles in diameter
3. Jupiter is 88,800 miles in diameter (at equator)
4. The Sun is 893,000 miles in diameter
5. Pluto is 1412 miles in diameter
   
6. The Moon is 238,900 miles on average from Earth
   
7. The Earth is 93,000,000 miles on average from the Sun
   
8. Jupiter is 483,600,000 miles on average from the Sun
   
9. Pluto is 3,675,000,000 miles on average from the Sun
   

Ok, so why are these solar system dimensions so hard to remember? (except for maybe the 93 million miles -- people seem to remember that one for some reason.) Because they're very BIG numbers that go beyond our everyday understanding. Most of us need to see things in comparison to other things to get some sense of how big or far away they are.

It seems that what we need is a model of the solar system just like we use a globe to see what the continents look like on Earth.

The only problem is that the smallest object in the model, Pluto, has to be 2.6 million times smaller than the largest distance in the model, the Sun-Pluto distance. The immense distances between planets in our solar system as compared to their sizes is why making an accurately "to scale" solar system model to be very difficult.

The best we can do is to make our model big, very, very big.

Currently there are at least 14 true to scale solar system models that I could find on the web. The solar system model in Peoria, Illinois, USA claims to be the world's largest at about 40 miles between the Sun and Pluto. Funny enough, the solar system model in Aroostook County, Maine also claims to be the world's largest, also at about 40 miles between the Sun and Pluto.

See a list of more solar system models at the site of the Alachua Astronomy Club, which is currently rebuilding their own Solar System model, which apparently has gone missing: Florida Solar System Walk.

You can make your own solar system model by visiting the Solar System Model Calculator. You simply enter the diameter of your Sun model (in inches or mm) and the calculator will give you the resulting sizes and distances to scale of the rest of your model.

Here is a great article on building a thousand yard solar system, if the earth were the size of a peppercorn: The Thousand Yard Model, or The Earth as a Peppercorn.

See more references here: Solar System Model metapage

Good Night!