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steelcryo t1_jb9nso4 wrote

The other comments have already answered the question, but I'm going to add in a bit of context that's really obvious, but rarely thought about and that is that the moon is massive.

We often think of the moon as quite small, because we see it in the sky all the time and it looks small. Then we get these really high resolution pictures of it, normally something you can't do at great distances. Which further increases the perception that the moon is quite small.

Truth is, the moon is huge. Compared to the Earth, it's small, but as a physical entity, it's pretty big. Now I'm saying all this to give some comparison to the main question.

This is the Tycho crater. It's not the biggest crater on the moon, but it is one of the most visually distinct in that you can easily see the edges of it. That crater looks fairly small, but is actually 83km in diameter. So if that's how small something 83km across looks, it puts into scale just how tiny something as small as a rocket/lander would be.

Yes, telescopes can magnify much more than that picture, but it gives a good sense of the scale of what you are actually trying to look at.

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extropia t1_jb9r3q7 wrote

That's a great example! Without any obvious Earth-like features like coastlines and clouds to compare it to, it's easy to look at the crater and think you could walk across it in a day.

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Mr__Teal t1_jbb7wvi wrote

It's 83km, you could walk that in a day at least on Earth. Might be easier to do an easy run on the moon rather than walk, but outside needing a support crew to resupply you with air you could probably do it on the moon as well.

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clonked t1_jbbwclz wrote

If you managed to do a constant pace of 15 minute miles, walking non-stop, it would take nearly 13 hours to walk ~51 miles (83 km). That is technically achievable, but not by a majority of people.

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zxyzyxz t1_jbcw5kz wrote

How does the lower gravity factor into it? Does it make it easier to walk across? What would the effort feel like as opposed to walking that far on Earth?

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clonked t1_jbd22vy wrote

The lower gravity can actually make you walk slower, because there is less ground tension from the lower gravity. Overall it would be a considerably harder task on the moon, their gravity is ~16% of what earth's is.

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Wild_Sun_1223 t1_jbc0bez wrote

Yes, since a Earth day is 86.4 ks, then you can do it at a walking pace of 83 / 86.4 ~ 1 m/s, which is slower than average (1.4 m/s). But in practice you'll wanna sleep, so maybe two Earth days is better than one. Note that regarding oxygen, bottles could be laid out in advance similar to an Everest climb on Earth, and there could be a half-way camper for sleeping.

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_Jam_Solo_ t1_jbbvelw wrote

I find 83km is less than I was expecting. That's not very far at all. It's like a 45min drive.

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Tidorith t1_jbcf8gb wrote

Linear distances are small, areas are large. It's easy to drive across an 83km crater, but imagine trying to paint the whole thing.

Volumes are even larger still.

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andrewmaixner t1_jb9rqlv wrote

And for those who benefit from geographic comparison, the moon is almost as wide as the continental United States, or 2/3 as wide as China.

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formerlyanonymous_ t1_jb9tqbf wrote

Huh, I'd definitely thought bigger. Thanks.

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coren77 t1_jb9xyaf wrote

Me too.... so I looked it up just to get a grasp on difference! From a purely diameter related measurement, the moon is ~2100 miles, while the earth is around 8000 miles in diameter. The US is around 2700 miles across depending on how you measure. However in actual square miles, the moon is MUCH more massive (sphere, yay!) than any one country on earth; the moon is around 14.6million square miles, wile the entire continent of asia is around 17.2million sq miles (largest country on earth, Russia, is "only" 6.6 million miles).

The More You Know!

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Legitimate_Bat3240 t1_jbamjqk wrote

Surface area of the moon is a few million less sq miles than the total surface area of Asia.

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andrewmaixner t1_jban7wi wrote

Yes. My super-basic comparison is based on diameter or width (not surface area), Asia is != China, and the moon is spherical not mostly-flat. This is "X river is Y football fields long" quality of comparison ;)

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