# Relative Distance of Planets and Size of Earth and Moon (10-27 thru 11-2)

The Mathletes discovered the relative distances of the planets from the Sun measured in Astronomical Units (AU). One AU

equals 93,000,000 miles, the distance from the Earth to the Sun.

Each student made an estimate of what they think the distances are of each planet to the Sun. Most students spaced the

planets out in equal distances the same way we usually view the Solar System in photographs severely not drawn to scale.

The actual distances are extraordinary. The Sun to Pluto is 40 AUs or 3,720,000,000 miles away. Below is what their

estimate may have looked like. Then we arrived at the actual by folding another sheet of paper in half, half, half, etc.

We also had the students separate three pounds of Play Doh into 50 equal parts using factoring (first into 5 equal parts and then 10 each).  They took one of the pieces and rolled it into a sphere (this represents 1/50th of the whole).  They took the rest and rolled it up into a larger sphere and that represented Earth.  The smaller ball represented the moon.

Each group then had to stand where they thought the Earth and Moon would be in relative distance to each other.  They were surprisingly close.  The moon is 30 Earth diameters away from the Earth (they had to stand 10 feet away)

THE CHALLENGE: Each Mathlete should write down why they think that the Moon and the Sun appear to be the same size in the sky when we know that they are not. You can write a paragraph or a page and bring it to class.

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PLANETS.pdf33.58 KB