20 December 2019: pacing off the distances to the planets. Students joined teacher and Head of School Dr. Lou Ellen Kay to walk down Avenida de Mesilla, placing scale models of the Sun and the planets at appropriately scaled distances. Starting from the Sun, represented as a paper plate 8” in diameter, they walked 10 paces (30 feet) to reach Mercury, where Lou Ellen drew a pinhead 0.03” in diameter to represent Mercury! On they went, to place planets out to Neptune at 777 paces! At the stopping point she spoke about the far greater reaches to the Kuiper Belt, then the scattered disk, then the end of the Oort cloud (at a real distance of 1 light-year, scaled to 50,000 times the distance to the Earth, or 1,300,000 paces, which is 740 miles, a walk down to Mazatlan, Mexico! We skipped that part.
Solar system model – Earth as a peppercorn
Sun-any ball, diameter 8.00 inches
Mercury-a pinhead, diameter 0.03 inch
Venus-a peppercorn, diameter 0.08 inch
Earth-a second peppercorn
Mars-a second pinhead
Jupiter-a chestnut or a pecan, diameter 0.90 inch
Saturn-a hazelnut or an acorn, diameter 0.70 inch
Uranus-a peanut or coffee bean, diameter 0.30 inch
Neptune-a second peanut or coffee bean
How Big is the Solar System? http://www.noao.edu/education/peppercorn/pcmain.html
This peppercorn is the Earth we live on.
The Earth is eight thousand miles wide! The peppercorn is eight hundredths of an inch wide. What about the Sun? It is eight hundred thousand miles wide. The ball representing it is eight inches wide. So, one inch in the model represents a hundred thousand miles in reality. This means that one yard (36 inches) represents 3,600,000 miles.
Put the Sun ball down, and march away as follows
10 paces. Call out “Mercury 0.4 AU 10 paces
Another 9 paces. Venus 0.7 AU 19 paces
Another 7 paces. Earth 1 AU 26 paces
Another 14 paces. Mars 1.5 AU 40 paces
Another 95 paces to Jupiter 5 AU 135 paces
Another 112 paces. Saturn 9.5 AU 247 paces
Another 249 paces. Uranus 19 AU 496 paces
Another 281 paces. Neptune 30 AU 777 paces