How Far Away is the Moon? (The Scale of the Universe)

If the Earth were the size of a basketball and the moon a tennis ball, how far apart would they be? Diagrams that are not to scale make us think that they're closer than they really are.

Category:

Education

Tags:

• moon
• earth
• scale model
• scale of the universe
• solar system model
• science literacy
• moon's orbit

[GodDamnPontiac]

with just a little bit of thought it would be easy to determine. the moon is roughly 126,000 miles from the earth and Earth's diameter is roughly 13-14,000 miles. which means you can fit 10 earths in between the orbit between Earth and Luna.

[1veritasium]

@GodDamnPontiac careful! The Earth's diameter is roughly 13,000 KILOMETERS (and the distance to the moon is actually 385,000km) so you can fit about 30 Earths between the Earth and moon.

[upurhoe12321]

Our nearest star is the god damned sun...

[1veritasium]

@EchoCosmic Wow. Because this is the internet I never know if people are just trolling. In case you're not, a basketball and a tennis ball are a pretty good scale model. Moon diam/ Earth diam = 3500km/12750km = 0.27 Tennis ball/Basketball = 6.5cm/25cm = 0.26

[ScienceofWinning]

@cynthiacalgaro the average distance between the earth & the moon is ~384400km, & the Earth's diameter is about 12756.2km, now you need only to scale them down. If we assume that the basketball has a diameter of about 23.85cm, we need only multiply that by 30.134 to get the distance that the tennis ball should be from the basketball. Roughly 7.16 meters. I hope that helped!

[ScienceofWinning]

@hooloovoo1st As you did, I'm sorry for that. You would indeed be correct then, the moon being roughly 9.592 Earth circumferences away from us at it's average distance.

[hooloovoo1st]

@ScienceofWinning Uhh, I said miles, and circumference. I didn't say km or diameter.

[ScienceofWinning]

@hooloovoo1st Nope!! the earth has a diameter of about 12756.2km, & the average distance between the Earth & the moon is ~384400km. This means that the distance from the Earth to the moon is actually about 30.134 times the diameter of the Earth. I actually made a prezi on Newton's law of gravitation that you can check out if you want. It doesn't have much in the way of conceptual explanation, but it walks through the calculations.

[ScienceofWinning]

@upurhoe12321 & the nearest star to our sun is Proxima Centuari, roughly 4 light years away :D

[hooloovoo1st]

@1veritasium The way I remember it (very approximately) is that the Earth is about 24,000 miles in circumference and the moon is about 10 times that distance away; 250,000 miles. Like I said, very approximate, but it helps me remember.

[cynthiacalgaro]

Thank you so much on behalf of the whole 4th grade! Kids love to see that adults don't know this stuff either. We'd like to replicate this question activity with the kids... Could you provide measurements for the distance between the Earth-basketball and Moon-tennis ball? 30 Earths is helpful, but it would be easier to have it in meters :-)

[lifeinpictures]

Cute, but you wandered off topic in your attempt to be hip and ironic. Dingus.

[Ratheos]

I was hoping he would just take the tennis ball and chuck it.

[mohamedgna]

his first mistake is that he used a tennis ball, the moon is roughly about quarter the diameter which makes guessing that much easier!