| ▲ | Zenul_Abidin 5 hours ago |
| You can literally find it in the air. |
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| ▲ | not_a_bot_4sho 5 hours ago | parent | next [-] |
| Like gold in beach sand. It's everywhere. But extracting it is expensive and not very economical. |
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| ▲ | GloriousKoji 5 hours ago | parent | prev | next [-] |
| There's more water in the air than helium. |
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| ▲ | thaumasiotes 2 hours ago | parent | prev | next [-] |
| In the air? That's the one place you can't find helium. The earth doesn't have enough gravity to hold it down; if it gets into the air, it escapes into space. Any helium we have comes from underground, which is why you can see discussion of "mining" helium upthread. |
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| ▲ | adrian_b 31 minutes ago | parent | next [-] | | No that is false. While it is true that helium escapes from the atmosphere, it is also produced continuously in the Earth's crust. Thus there is an equilibrium concentration of helium in air, from generation and loss, and it is greater than for the heavier noble gases krypton and xenon, which do not escape from the atmosphere. So there is more helium in air than krypton and xenon, which are nonetheless extracted from air, despite their low concentration. However, their extraction from air is easier than for helium, because when liquid air is evaporated the lighter and more abundant gases evaporate first and krypton and xenon remain in the small liquid residuum. | |
| ▲ | BizarroLand an hour ago | parent | prev [-] | | The earth has plenty enough gravity to hold down helium. It's the rest of the atmosphere, being denser and heavier than helium, that counteracts earths gravity and forces it up to the top where solar winds dislodge it. |
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| ▲ | mttch 3 hours ago | parent | prev [-] |
| Or the moon, or Uranus |
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| ▲ | shagie 3 hours ago | parent [-] | | Helium on the moon is much more interesting than helium on the earth. Most of the helium on the Earth is from radioactive decay. The helium on the moon, however, is from capture from solar wind... and has a higher concentration of helium 3. https://www.esa.int/Enabling_Support/Preparing_for_the_Futur... | | |
| ▲ | thaumasiotes an hour ago | parent [-] | | > Apart from the traditional space-faring nations, the India has previously indicated its interest in mining the lunar surface. What happened here? Does the European Space Agency not have anyone who can proofread an English document? Why are they publishing in English? |
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