Some examples/analogies that help convey the scale of space?

[EnigmaSCADA]

When discussing a space related topic with someone who is not necessarily enthusiastic or formally educated on the topic, I find that there's often a large misconception of scale when people imagine earth (as it sits in the darkness of space), distances (near earth, solar system, and beyond), and time + speed of course.

I believe this is due to 1) the inability of Joe Average to observe these qualities first hand on a daily basis, 2) educational/entertainment images & examples not being to scale at all (mostly for practical reasons, think of the average classroom solar system model done to scale), and of course 3) Hollywood's needs.

Over the years I've read a few really great examples/analogies that help convey the true scale to the average person and are especially helpful when educating children. Many of which, I can't recall easily. For example:

Regarding distances/size: If earth were a peach, the ISS would be skimming the fuzz.

Regarding "crowdedness" of satellites: Imagine ~5000 people lived scattered around earth. Chances are they would live out their entire lives without ever knowing they weren't alone."

I was hoping to compile more examples like these that convey the scale and scope of space to anyone, child or adult. Please share any that you think are good for this purpose.

[incoming]

Here's a try.  It's hard when you get bigger than the solar system because the distances are so absurd...even if you imagine the earth as the size of a grain of sand, the nearest star to ours would still be 4,000 km away, which is about the distance from San Diego to Hawaii. [edited]

But...if Earth were about the size of a baseball, and you set it on home plate of Nationals Stadium, which is in the very southern edge of Washington D.C....

...the ISS would be right next to the baseball, separated by about the thickness of two nickels
...the moon would be about 1/4 of the way to the pitchers mound, or about the distance a decent bunt travels down the third baseline
...the orbit of Mars would be well past the left field fence, about a block and a half past the entrance to the stadium
...the orbit of jupiter would be across the city, almost to maryland
....the nearest edge of the oort cloud would be past the Canadian border
....the farthest edge of the oort cloud, more or less the edge of our solar system, would be half way to the moon (really gives you an idea of how big the oort cloud is)
...the nearest star would be just past the moon. [edited]

I'd encourage you to build your own spreadsheet and experiment. Make a column of solar system distances, then scale the earth to be whatever size you want, scale the other distances by the same amount, and see what you come up with. If nothing else it will help YOU to get your mind around some of the distances...

also this is a cool website for visualizing - http://www.distancetomars.com/

have fun!

edit - i welcome someone to check my math...
edit 2 - a km to m conversion got me off by 10^3 on alpha centuri. Now fixed in both examples. 

[Crispy]

I checked your math* and made a quick spreadhseet
https://docs.google.com/spreadsheets/d/1hY_X2gIiRAe-EM4P3ktHoK5iPaIaGkZ5lMZfEpLcgrE/edit?usp=sharing

If the earth is 1mm wide, then it orbits 12m from the sun and a-Centauri is ~3,250km away, not 4 million.

Here are some more fun comparisons:

If the Earth was at the other end of a football field, it'd be the size of a grape. The moon would be the size of a lentil, at an outstretched-hand orbital distance from it. You'd be holding a yoga-ball sized sun.

If Neptune was at the other end of a football field, the sun would be the size of a quarter in your hand and Earth would be the size of a period mark in a paperback book. It'd be 9 ft away from you.

If  a-Centauri was at the other end of a football field, the whole solar system (up to Neptune) would fit on your pinky fingernail. The orbital radius of Earth is about as thick as that nail.







*s - please check mine also!

[1]

In the Entertainment/hobbies thread, there's a fellow in Finland who's made a scale model of the solar system. Although most of his model fits in the Finnish city of Akaa, Proxima Centauri is "close" enough that he was able to find someone to help him mount it in Australia. The thread's a fun read; go check it out.

https://forum.nasaspaceflight.com/index.php?topic=40636.0

[Lunadyne]

One of my favorites is the Toilet Paper Solar System.  I've used this one a number of times and it really does help convey some basic concepts about the Solar System, like the  rocky planets vs. the gaseous planets,

What's needed:

-300-sheet roll of toilet paper (each sheet represents ~20,000,000 km)
-pictures of the planets and other objects (I use some flash cards culled from a space card set)

Unroll the toilet paper and place the planet or object on the respective squares:

Sun:  1
Mercury: 3
Venus:   5
Earth:    7.5
Mars:    11.5
Jupiter:   39
Saturn:   72
Uranus:   144
Neptune:   225
Pluto:   300

I also have some asteroid belt cards I put between Mars and Jupiter, and some Kuiper Belt objects I put way out beyond Pluto.  If you wanted to include Alpha Centauri you would need an additional 7,000 rolls.

While simplified, it really does a good job conveying the scale of the Solar System to the general public.

If you're doing this at a public museum or planetarium, you should also make use of their change funnel to explain some basic orbital mechanics and the idea of gravity wells.