June 16, 2021: A summer project is to build a sidewalk solar system model. The scale uses the sun’s size as the size of a basketball. Earth’s distance is 88 feet.
by Jeffrey L. Hunt
Build a sidewalk solar system model. It’s a great summer project to show children the relative sizes and distances of the sun and planets.
The equipment needed is a tape measure (the longer, the better), sidewalk chalk for temporary markers or spray paint for a longer-term model.
With any model, making all the scales work is the challenge. This is evident with the relative sizes and distances of the planets. Can we make the planets large enough, but keep their distance from the sun reasonable? Well, not really. A long neighborhood sidewalk is needed.
We start with the sun’s actual diameter, 840,000 miles. Let’s reduce it to the diameter of a basketball, about 9.55 inches. At this scale the planets’ sizes are tiny, especially the inner planets until Jupiter is marked. Then place the planets at their distances from the sun.
|Object||Scale size (inches)||Scale Distance (feet)|
If you’re building a classic solar system, including Pluto, its distance from the sun in 2021 is 3018.4 feet from the sun. The planet is small, only 1/200 inch, just a tiny dot.
Have fun with this model.
Articles and Summaries
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- Venus Evening Star (Summary)
- Mars during 2021 (Summary)
- Planets during June 2021
October 5, 2021: Before sunrise, a very thin moon is visible in the eastern sky. The evening planet pack – Evening Star Venus, Jupiter, and Saturn – are visible at the same time after sundown.
October 29, 2021: Today is the date for equal daylight and equal darkness for about 42° north latitude. This is not to be confused with the autumnal equinox.
October 4, 2021: Before sunrise, the razor-thin lunar crescent is low in the eastern sky.
October 3, 2021: Before sunrise, the thin crescent moon is in the eastern sky, to the lower left of Regulus. After sunset, the planet pack – Evening Star Venus, Jupiter, and Saturn – shine brightly.
October 2, 2021: The crescent moon appears near the head of Leo in the eastern sky this morning before sunrise.