If the earth were the size of a tennis ball how big would the sun be and how far apart?

Question

Please use good guestimation. Would our nearest star be much further away proportionately. Please calculate using mean distances etc.

Answer 1

someone else has already done this experiment. It doesnt' have all the stuff you asked for, but it is close... and use the stuff above for the size of the sun.

Again, start by setting the stage: that we will take the entire sun and scrunch it down to a 3-inch ball. A tennis ball (or lacrosse ball) is about right, but I have also used a small orange or tangerine to good effect (especially since the Florida Orange Growers Association would have us believe that oranges are "captured" sunshine!).

Now go through a few steps from the table above. It is good to include the earth as a reference point, and Jupiter because it is the largest planet. Including Saturn (the next planet out from Jupiter) is nice because it shows how quickly the distances get very large for the outer solar system, and Pluto, for better of for worse, is recognized as the most distant planet (although no longer considered to be the "edge" of the solar system--but that is another topic). That Pluto is more than three football fields away from the "orange" sun can be made even more effective if you are standing on or near a football field at the time! Also, reinforce the idea that these distances are the radii of the orbits--that each planet sweeps out a big "circle" in its trek around the sun.

The zinger here, of course, is if you make the last step in the table above (to the NEXT nearest star). Pictures of star clusters or nearby galaxies are misleading in a sense because the true distances between objects are not often placed in the proper context. Our Galaxy, the Milky Way, is a huge spiral of stars about 100,000 light years across. About 100 BILLION star populate the Galaxy. The sun and its nearest stellar neighbors are quite similar in size and temperature, and so the "orange" remains a good size reference. However, the distance is another matter altogether. Instead of using feet or football fields, we must increase the yardstick to miles or kilometers. The next nearest star to the sun is another orange-sized object more than 1400 miles away! I leave the possibility of describing the size of the Milky Way on this scale (100,000 ly = 33 million miles!) to your discretion, but I think in general this distance loses its meaning to most people.

3. Other Scalings

You can generate other scalings to your heart's content; really all you need is a good astronomy textbook with some numbers and a few props of the right approximate dimension. Here I mention just two others: one that "combines" the above two demonstrations into one (shorter) demonstration, and one that takes another big step out into the Universe.

a) Intermediate Scaling Example

In many situations you may want to set the scale for more than just the earth--moon system, but leaving the earth as a totally insignificant grain of sand may be going too far for your tastes. I have used the following scaling and effectively combined some highlights from both of the above demonstrations into one presentation with good results. In this one, we let the earth be scaled down to 3-inches (instead of the sun), which keeps most of the sizes and distances within the realm of understanding. I find it particularly effective to use an earth "ball" or paperweight with the continents marked. Squishy earth balls of about the right dimension are available in many gift or toy shops at very reasonable prices.

Table 3

Solar System Scaled to 3-inch Earth

Parameter Real Distance/Size Scaled Distance/Size
----------------- ------------------- ---------------------

Earth (diameter) /12,756 km/ 3 inches
Moon (diameter) /3,476 km / 0.8 inches (ping pong ball)
Moon (distance) /384,400 km/ 7.5 feet
Sun (diameter) /1,392,000 km/ 27.3 feet
Sun (distance) /150 million km = 1 AU / 0.55 miles (=0.9 km)
Jupiter (distance) / 5.20 AU / 2.9 miles (from sun)
Jupiter (diameter) /142,984 km/ 2.8 feet
Saturn (distance) / 9.54 AU / 5.2 miles (from sun)
Saturn (diameter) /120,536 km/ 2.4 feet
Pluto (distance) /39.54 AU / 21.7 miles (from sun)
Pluto (diameter) /2,300 km/ 0.5 inch (small rubber ball
or crumple up some tin foil)

Next nearest star /4.3 light years / 156,000 miles (or more than 6/10ths
of the way to the moon on the
"real" scale of things!)

Answer 2

The earth is 7900 miles in diameter. The sun is 864,000 miles in diameter (equal to 109 earths) and is about 93 million miles away (about 12,000 earths).

A tennis ball is 2.5 inches in diameter. (Call it roughly 5 to the foot or about 25,000 to the mile.) On the tennis ball scale, the sun would be 109 tennis balls wide, or about 250 inches, which is about 21 feet. The sun would be 12,000 tennis balls away, which is about half a mile.

Alpha Centauri is 4.3 light-years away which is about 240,000 times as far as the sun. So on the tennis ball scale, Alpha Centauri would be an object also about 21 feet wide, about 120,000 miles away, or about halfway to the moon.

Answer 3

If a tennis ball has a diameter of about 8 centimeters The Sun at this scale could have a diameter of 8,76 meters and it would be 942,36 meters away from the tennis ball.

Answer 4

you can fit roughly 1,000,000 Earths into a comparable area the size of the Sun. Figure out how big the tennis ball is and multiply by 100.

Answer 5

Wow, Thank you! I was asking myself the same thing the other day