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Collecting Stardust
An anonymous reader writes "Washington University in St. Louis space scientists are reporting the first definitive laboratory dissection of an interstellar dust particle, thus pulling out each grain's history individually. When collected at high-altitude, the origin of six grains are from outside our solar system. 'Space' is full of dust, or ejected material from long-dead stars. In this case, 3 of the 6 dust grains are from red giant stars, and perhaps 2 are from supernovae. In the next 5 years, there are six missions targeting a rendezvous with either a comet or asteroid, including the Stardust mission to return the first extraterrestrial samples since Apollo. That only leaves 100 billion comets left to explore in our own solar system's Oort cloud." Update: 02/28 17:22 GMT by M : Fixed university name.
When collected at high-altitude, the origin of six grains are from outside our solar system.
IIRC, someone once wrote that "...even God cannot tell carbon atoms apart." How do you pull something from the upper atmosphere and conclusively determine that it came from outside the solar system? Perhaps it would help to RTFA (and I will) but it just baffles me how these scientists are able to figure this stuff out. I'm starting to fall into that "Science as magic" category, I guess.
GF.
Lots of petrified grits
I suggest they check out the moon's craters for the dust residue from asteroid impacts...
this is not a sig.
> I found it interesting that commercial mining of asteroids was mentioned
> in the third article. Sure, raw materials are plentiful in asteroids,
> but wouldn't the cost of getting there far outweigh the benefits
> of the plentiful resources? I guess this would be practical if/when
> we run out of certain ores, or as an "While we're here, we might
> as well" measure, but I can't see it going anywhere otherwise
> until the price of space travel drops dramatically.
Yeah, it's an "economy of scale" thing. Once we have regular (and by regular I mean many companies each making daily launches) access to space, the incremental cost of space travel will be far, far below what we pay now in terms of cost per unit mass.
And, thing is, it doesn't cost much in terms of energy to get to any given asteroid once you're outside the gravity well of Earth. The only cost would really be time, since momentum keeps you going until you want to brake. So you start up a pipeline of automated mining probes to Ceres. Much like on modern microprocessors, the initial hardware cost would be greater, but you'd be able to transport mining materials at a much faster and more reliable rate than you otherwise would.
And mining in a low gravity environment (Ceres, the largest asteroid, has less than a thirtieth of Earth's surface gravity) should be far less energy intensive than mining on Earth, where you have to expend unbelievable amounts of energy to merely move mined elements from the mines to the transports, and where you're severely limited in machine travel range due to friction related to that nasty 9.8m/s^2 that we have to put up with all the time here.
And some asteroids will probably have minable minerals in abundance, and remote spectral analysis will be able to allow us to identify mineral compositions from millions of miles away. That does away with a huge portion of the work involved in mining on Earth, where you have to often indirectly figure out what minerals are hidden beneath the surface, wasting time by drilling all over the place. That costs money continuously, and you could save on that with asteroid mining.
There are probably some other things in asteroid mining that I'm not thinking of. I'm not miner, and my "engineering" knowledge is rather amateurish (I'm more of a theoretical guy, being a programmer and all). Maybe wear and tear of machines would be less (due to both that lesser gravity we discussed above and the total lack of atmosphere or microorganisms to break down the machine parts). Maybe there are social benefits, like higher morale for the folks who like to work in larger and more open environments (this century, maybe "getting away from it all" will mean accepting a job that lets you work fifty million miles away for a year or two).
Economies of scale, my man. We have to force ourselves to pay the high costs to continue the proliferation of new technology. I we don't do this, we go stagnant. Space launches these days are often more expensive than they were in the old days, even when you take inflation into account. It's because we stopped doing them so often. It saves a few billion dollars a year in the short term. But we might have made back those billions -- and far more -- by now from the direct and indirect benefits of building up an economy-of-scale framework of space travel. I mean, heck, we landed on Luna six years before I was born. We have space probes ten light hours away. We also have advanced manufacturing facilities on Earth now. Had we continued our push into space instead of borking it all in the seventies through the nineties, I imagine that we would have simple factories producing complex objects on the cheap (at least with products that require tons of work on a small amount of raw material -- no friction and no gravity equals huge cost reductions!) now. Chip fabbing companies would be looking at near to medium term options for building astro-fabs. Do you realize how much more precision in the sub-nanometer range you'd get in building chips when you don't have to worry about gravity and vibrations from the local landmass and atmospheric variables? I mean, crap, we probably would be able to further accelerate process shrinks. 3.0GHz on a 130nm process? What a backwards technology for a space-enabled 2003!
Economies of scale, my man. Startup costs are [almost] always prohibitive. That's how science and technology works. Live with it. But don't work to inhibit it.
-JC
Most of modern astrophysics isn't scientific, in fact.
As someone who studied astrophysics at university, I can honestly say that statement is just bull. Yes, astrophysics is mainly a theoretical science, but that doesn't make the science any less valid.
The fact that you couldn't get through reading A Brief History Of Time without dismissing its contents as "anything more than fantasy" suggests to me that you're the kind of person who doens't have the capacity for anything other than simple thought.
I'll ask you two simple questions that illustrate just how dependent science in general is on theories:
Q: How do you know that the Earth is round? (Ie, how can you prove it?)
Q: How do you know that gravity exists? (Again, prove its existance.)
Observational astronomy has helped astrophysicists prove and refine their theories. Want proof of the effect of gravity on light as predicted by Einstein's Theory of General Relativity? Then just look at gravitational lensing caused by the Sun. Etc, etc.
Astrophysics may be a relatively new science (it's less than a hundred years old) but it's backed up by astronomy (the oldest science) pretty damn well.
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg