Could living on/ mining the moon cause unintended consequences for Earth? e.g. changes in tide or anything else?
In: 248
So if we are just living and mining on the moon, nothing changes.
Moon’s gravity effect comes from moon’s mass. if we are just mining and living on the moon, the stuff isn’t going anywhere, moon maintains its mass.
But if we start to strip mine it and ship the stuff back to earth. over a long period of time, it will gradually lose gravity, and we’ll see the effect.
No, not unless we transfer a substantial fraction of the Moon’s mass to Earth, which we will never do.
Likely not. At least to a functional level. *Technically* any removal of mass would *technically* change the interaction but at the scale of tides, not a functional amount.
Even more so in our lifetime and the next few generations.
The moon gets hit with a literal metric ton of meteorites a day.
Plus, it already has a mass of 73,430,000,000,000,000,000 metric tons already.
Scratched a bunch of math since it got lost in the sauce. In effect, the biggest mines on earth in far easier conditions and longer time scale would barely make an impact.
To have a serious effect on the gravitational pull it would take a huge undertaking to move that much mass.
Edit – I’m asking because I presume the plan is to move the mined material back to Earth. So over time the mass would be getting lower at some rate
Consequences? That depends at least partly on how you decide to get the stuff you’ve mined back down to earth. The cheapest way is probably to fling it into space and let earth’s gravity pull it in. The only snag there is that it will be coming in at 25,000 mph and yeah, there will be consequences.
This idea is worked up in more detail in Heinlein’s “The Moon is a Harsh Mistress”.
No. No amount of mining on a human scale would have significant consequences for the moon’s orbit or tides or anything like that.
You could take the total amount of everything that humans have ever mined in the entire history of humanity, multiply it by a million, and transport it from the moon to earth, and it still would not have a significant effect on the moon’s orbit or the tides. The moon is just too big. Any amount of mining significant enough to effect the moon’s orbit or the tides in a noticeable way would already effect the earth even more dramatically by covering it in a noticeably thick layer of moon stuff. That’s how much you’d need to import, it would be so much that it would cover the earth in a layer of moon.
Okey let’s see. We mine around 15 billion tonnes of material per year on Earth. Let’s say we aim for the same amount to be mined on the moon. This is of course oversimplification as the minerals are quite different , in the beginning we would mine not even a millionth, but over a long time we may mine more.
Anyways keep it simple.
Let’s assume that to have a significant change, we would need to mine and ship away 0.1% of the moon’s mass. This would take approximately 7.34*10^22/(1.5*10^10) * 0.001 years . Or roughly 4.89 billion years.
I think we are safe
Let’s look at some numbers – the mass of the moon is ~7.348×10^19 metric tons. It’s composed of a number of different minerals, but assuming we need a change of at least 1% in the total mass, the only ones to really look at are aluminum and silicon. On an annual basis, we’re currently extracting and using 65M and 8.5M tons of aluminum and silicon respectively. So, if we were to set up operations on the moon extracting 10 times that much every single year (so 650M tons of aluminum and 85M tons of silicon) how long would it take before we’d removed 1% of the moon’s mass?
Just under a billion years. The moon’s *way* more massive than you might think. We’ll evolve into non-human creatures before we’re able to affect the tides by mining the moon.
Each year, we mine a total of about 61 billion tons from Earth. The Moon has a mass of roughly 80 quintillion tons. That is, if we mined the Moon at the same rate as we mine the Earth currently and shipped all of that back to Earth, we’d reduce the mass of the Moon by about 10% of 1% of 1% of 1% per year, or 0.0000001%. At that rate, we might start to see effects in 100,000 years., when the Moon’s mass has been reduced by 0.01%.
I doubt we’d get even close to mining the Moon at that rate, and, even if we did, a lot of the minerals would likely be left on or around the Moon to build infrastructure. Realistically, the problem rate would take closer to a billion years to hit, and the Sun is only expected to last about 5 billion years.
They blew up the moon building moon condos or something like that in “The Time Machine”.
I need to watch that movie again!
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