Science: asteroid vs. hero physics

[Eltab]

One option would be to use it to break down matter on the asteroid, turn it into pico-printer-gel manufacturers, and then use those in turn to break down more of it, in an exponential replication loop. Once the whole thing is turned into printers, they then turn each other into propulsion units and fly themselves away.

The last third of 2010. It makes a good plotline.

But the author wants Our Heroine to be in peril at the climax, not watching safely from a short distance.
Maybe her suit gets infected with the 'make motors' nanite-virus, too? Or would that distract from the big picture?

 

[Janx]

With a mass driver you could scoop up stuff from the asteroid itself!

That would work for a distant asteroid, but doesn’t seem to work for an an asteroid which is at most a day away.

Thx!
TomB

Good idea. I figure to limit the pico-printer-gel to arranging atoms/molecues. So I need carbon and hydrogen to make hydrocarbons, frex.

Did we ever figure out the composition of the asteroid? Making rockets or mass drivers (hers are bracelet/anklets, so bigger=better). Seems a modest upscale could be feasible. and justify the # fig newtons needed to entice this beast to move.

Do we know what asteroids are made of before we get there? Presumably kind of yes, but how much do we know?

 

[MarkB]

The last third of 2010. It makes a good plotline.

But the author wants Our Heroine to be in peril at the climax, not watching safely from a short distance.
Maybe her suit gets infected with the 'make motors' nanite-virus, too? Or would that distract from the big picture?

Maybe distance isn't an option. The pico-gel printers can relay commands between each other, but her suit is the command node for them, and needs to be in the loop, so she has to remain physically present during the whole process.

 

[tomBitonti]

Good idea. I figure to limit the pico-printer-gel to arranging atoms/molecues. So I need carbon and hydrogen to make hydrocarbons, frex.

Did we ever figure out the composition of the asteroid? Making rockets or mass drivers (hers are bracelet/anklets, so bigger=better). Seems a modest upscale could be feasible. and justify the # fig newtons needed to entice this beast to move.

Do we know what asteroids are made of before we get there? Presumably kind of yes, but how much do we know?

Re: Asteroid composition. Then short answer is that it varies, according to distance from the sun:

Beyond their shape, there are a number of ways to classify asteroids. The first is by composition. The typical composition of an asteroid depends on its distance from the Sun. At the outer edges of the asteroid belt, that is between three and three and a half times further from the Sun than the Earth, over eighty percent of the asteroids are known as C-type.

The C stands for carbon and the surfaces of these asteroids are almost coal-black. These asteroids contain large quantities of carbon molecules as well as the more usual rocks and metals. They are very similar in composition to the carbonaceous chondrite meteorites that sometimes fall on Earth. It is thought that these meteorites are chippings, smashed off during collisions between asteroids.

Closer to the Sun, at just over twice the Earth's orbital distance, the proportion of C-type asteroids is only about 40 percent. Here, the majority of asteroids are grey, without the carbon material and principally made of silicate compound rock.

For more details, I tried Mineralogy and Surface Composition of Asteroids, Vishnu Reddy, Et. Al.
https://arxiv.org/ftp/arxiv/papers/1502/1502.05008.pdf
But it is far too dense, and doesn't present composition results in any simple representation.

Further searches found:

The majority of asteroids fall into the following three categories:

C-type (carbonaceous): Includes more than 75 percent of known asteroids. Very dark with an albedo of 0.03-0.09. Composition is thought to be similar to the Sun, depleted in hydrogen, helium, and other volatiles. C-type asteroids inhabit the main belt's outer regions.

S-type (silicaceous): Accounts for about 17 percent of known asteroids. Relatively bright with an albedo of 0.10-0.22. Composition is metallic iron mixed with iron- and magnesium-silicates. S-type asteroids dominate the inner asteroid belt.

M-type (metallic): Includes many of the rest of the known asteroids. Relatively bright with an albedo of 0.10-0.18. Composition is apparently dominated by metallic iron. M-type asteroids inhabit the main belt's middle region.

And:

In broad terms there are three classifications of asteroid based on their composition:

C-type, which are the most common, are carbonaceous, and consist of clay and silicate rocks. They exist furthest from the Sun, and so have been least altered by heat, meaning that they are the most ancient. Due to the fact that some have never even reached temperatures above 50°C, it is estimated they can contain up to 22% water.

S-type or silaceous asteroids are made up primarily of stony materials and nickel-iron. They inhabit the inner Asteroid Belt.

M-type, or metallic, are made up mostly of nickel-iron, and are found in the middle region of the Asteroid Belt.

What I've read (albeit, mostly science fiction) has mass driver payloads jacketed in iron, because a magnetic material is needed for the mass driver.

Thx!
TomB

 

[Eltab]

Do we know what asteroids are made of before we get there?

Somebody mentioned upthread that this is not a natural asteroid, it is a thrown projectile. The throwers, if they want to maximum damage, would send a metallic slug down on the target. Next best would be a stone composition. Iceballs will not melt as much as you would think in fiction, but still are brittle and could be shattered / broken into chunks /melted with the 'magnifying glass' trick before arrival.

Want to throw the readers for a loop? The thing used to be a carbonaceous chrondite, and inside a magnetic jacket is mostly oily goop, frozen or molasses-like or quicksand-y due to vacuum and ambient light / heat.

 

[Janx]

Somebody mentioned upthread that this is not a natural asteroid, it is a thrown projectile. The throwers, if they want to maximum damage, would send a metallic slug down on the target. Next best would be a stone composition. Iceballs will not melt as much as you would think in fiction, but still are brittle and could be shattered / broken into chunks /melted with the 'magnifying glass' trick before arrival.

Want to throw the readers for a loop? The thing used to be a carbonaceous chrondite, and inside a magnetic jacket is mostly oily goop, frozen or molasses-like or quicksand-y due to vacuum and ambient light / heat.

Actually, Marsies flew over and grabbed some rocks and flung them at earth because they were tired of taxation without representation.

 

[Umbran]

Actually, Marsies flew over and grabbed some rocks and flung them at earth because they were tired of taxation without representation.

"We are tired of taxation without representation. So, we will murder billions!"

Yeah, that's some ethical high ground there. :/

 

[Tonguez]

Maybe they don’t have tea on Mars

 

[Janx]

"We are tired of taxation without representation. So, we will murder billions!"

Yeah, that's some ethical high ground there. :/

Allegedly they did feel bad about it. Nobody's exactly gotten their side of the story other than they tried to stop the second launch.

Who knows how it really went down...

I just figured it was enough of a twist on the previous two perspectives I present.

 

[Umbran]

Allegedly they did feel bad about it.

"Yeah, we feel really bad about destroying the birthplace of humanity. But there was serious cash involved...."

Nobody's exactly gotten their side of the story other than they tried to stop the second launch.

Who knows how it really went down...

The only really relevant point is that it didn't go down *accidentally*. There is no, "Whoops! We threw a mountain-sized rock across interplanetary distances, and *just happened* to hit the Earth. So sorry!" Whoever did it, meant it. Consider what would be necessary for that to place those responsible on the right side of history.