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