Scale Model of the Solar System
You have often seen drawings showing the relative sizes of the planets, and even concentric circles showing their relative distances to scale (more or less). This may be the first time you have seen instructions to make a model of both the sizes and distances to the same scale. Perhelion is the closest distance to the sun, and Aphelion is the farthest. All planets travel in eliptical orbits.
|The Sun||10cm diameter 40 watt bulb||0||0|
|Mercury||1/3mm paint drop||10 3/4 feet||16 1/4 feet|
|Venus||1mm paint drop||25 feet||25 1/2 feet|
|Earth||1mm paint drop||34 1/2 feet||35 2/3 feet|
|Mars||1/2mm paint drop||48 feet||59 feet|
|Jupiter||10mm white marble or bead||173 feet||191 feet|
|Saturn||8 1/2mm hatpin or pearl||316 feet||353 feet|
|Uranus||3 1/3mm map pin or pearl||642 feet||705 feet|
|Neptune||3 1/5mm map pin or pearl||1045 feet||1063 feet|
The construction of this model began with a common pin. The head of it was painted white by dipping it into white paint, and it was mounted on a small black rubber stopper from a chemistry laboratory. The white spherical paint drop represented the Earth, and the stopper made an unobtrusive base, and a handle with which to pass it around. Soon an angle of fine wire was added with a smaller drop of paint to represent the Moon (distance from Earth = 27mm). Eventually the Sun and all the other planets were collected.
The table above represents the entire collection in its present form. If you will get out your paint, wire cutters, pins, etc. you can build your own. Buy a spherical light bulb to represent the Sun, the frosted decorative type that is about four inches in diameter. It is about 40 watts and will cost a couple of dollars. Get an adapter that will hold the bulb on one end and plug into a common power strip on the other.
My Jupiter is a marble from a Chinese Checker set, epoxyed to a small nail. If you can find a marble with some reddish streaks and a spot, so much the better. Hardware stores sell decorative wooden beads about that size, or you might have a broken set of pearls from an old necklace. Saturn, Uranus, and Neptune were made from an old hatpin and map pins which already had heads about the right size. I added a 19.5mm paper disc to Saturn for the rings. Venus and Mars are about the same size as ordinary common pins. For the smallest planets, use needles or cut the heads off pins and paint the cut ends with the smallest drops possible, or see if your local biology teacher will give you some tiny insect-mounting pins.
At the same scale, the nearest visible star (Alpha Centauri, roughly the same size as the Sun) would be at a distance of 1800 miles.