Hacker News Reader

Comment by swagasaurus-rex | Hacker News Reader

How much volume is actually available inside of asteroids that populate our solar system?

This xkcd talks instead about surface area, but suggests that the Earth holds a good chunk of the mine-able volume that can fuel industry.

Now, if we could siphon off hydrogen from the gas giants and fuse them into heavier elements, we could have orders of magnitude more material to work with.

View on HN

It isn't just surface area, but also the elemental composition. When the earth was molten, every siderophilic[0] element sank into the earth's core, leaving the crust with relatively low concentrations of precious metals[1]. All the precious metals we can mine are from later asteroid impacts, not the initial material that formed the earth. Mining asteroids would potentially give us more access to those precious metals.

[0] https://en.wikipedia.org/wiki/Goldschmidt_classification#Sid...

[1] https://www.sciencedaily.com/releases/2011/09/110907132044.h...

Not sure about volume but mass wise it’s a drop in the bucket. About 4% of the moons mass according to Wikipedia.

I was surprised to learn that the earth is about as massive as Mercury, Venus, Mars, the moon and a few more moons combined.

The Earth is too massive - almost all of the earths mass is below the crust and inaccessible due to extreme temperatures and pressure, bad sci-fi movies not withstanding.

Most asteroids have so little gravity that mining them out would be quite feasible.

Reply on news.ycombinator.com