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Easily-Captured Asteroids Identified
Hugh Pickens DOT Com writes "Long overlooked as mere rocky chunks leftover from the formation of the solar system, asteroids have recently gotten a lot more scrutiny as NASA moves forward with plans to capture, tow, and place a small asteroid somewhere near our planet. Two different private space companies, Planetary Resources and Deep Space Industries, plan to seek out and mine precious metals and water from near-Earth asteroids. Now Adam Mann reports that astronomers have identified 12 candidate Easily Retrievable Objects (EROs) ranging in size from approximately 2 meters to 60 meters in diameter that already come (cosmically) close enough to our planet — close enough that it would take a relatively small push to put them into orbits at Lagrange points near Earth using existing rocket technology. For example, 2006 RH120 could be sent into orbit at L2 by changing its velocity by just 58 meters per second with a single burn on 1 February 2021. Moving one of these EROs would be a 'logical stepping stone towards more ambitious scenarios of asteroid exploration and exploitation, and possibly the easiest feasible attempt for humans to modify the Solar System environment outside of Earth (PDF),' write the authors in Celestial Mechanics and Dynamical Astronomy. None of the 12 ERO asteroids are new to astronomers; in fact, one of them became briefly famous when it was found to be temporarily orbiting the Earth until 2007. But until now nobody had realized just how easily these bodies could be captured."
Looks like it's time to build a foundry in space so we can begin the construction of satellites, space stations and long range spacecraft with materials readily available in space, so we don't have to keep carting it up there. Between that and robots and assembly machines, we should be able to build out stuff in the next couple decades.
Watch for Penguins, they eat Apples and throw rocks at Windows.
I know the article talks in relative terms - but changing a massive object's velocity by 58 m/s is not trivial. Also, this assumes the asteroid isn't tumbling or rotating. You would have to cancel this before actually attempting to move the object.
or easily retargeted to hit DC? How long before the politicians demand trillions on behalf of their owners to protect the U.S. from the "asteroid threat". War on Space, here we come!
It doesn't have to hit Earth to affect it. Consider the tides. Our global eco system has evolved to expect tides. It would be difficult if not impossible to predict the full extent of the harm that could result if tidal patterns are altered. All sorts of life could flourish or die under such changes.
I'm not exactly a tree-hugger, but I certainly appreciate the factors and influences over life on this planet. This would affect the oceans in all sorts of ways. That which affects the oceans and the life within them will affect us and possibly even global weather patterns.
Because a 2~60m diameter stone in space can significantly alter tides.
It doesn't have to hit Earth to affect it. Consider the tides.
Why not consider the Lily? Look, the largest of these objects is sixty meters in diameter. I'm math-challenged, but a quick back-of-the-napkin calculation reveals marinara sauce and a little olive.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
There's stuff whizzing past us all the time with the gravitational attractive force that these rocks will have. It's not going to impact tidal patterns until we start capturing relatively large objects... like relative to the moon kind of size.
You know you only have to stand about 6 feet away from somebody to have the same gravitational pull on them as Mars has on you when it's closest to earth?
Mars already impacts our tidal patterns more than these rocks.
And what happens if, due to a malfunction, the thruster doesn't shut off when it's supposed to, and it burns for longer than 58 seconds?
People got angry about BP, and before that the Exxon Valdez, but that was after the accidents had already happened. What happens when a greedy grab for extraterrestrial ore inevitably goes awry? And make no mistake; over the long hault, it is inevitable. Even if the first attempt, hell the first five such attempts, go off without a hitch, there would eventually, over many such attempts, be a critical error on a similar mission.
There would be no time for recriminations and lawsuits then.
Can't we just get Sephiroth to use the black materia to summon Meteor? That pulled in an asteroid pretty damn quickly IIRC...
We aren't ruining the planet. By all measurements of health, wealth, and longevity, we are doing better than ever before.
The counter-intuitive reality is that, in an economically free society, people will solve problems faster than they become serious. This theory has successfully made predictions over 10 year periods over and over again.
The days of politics as memes figting in your brain should be over.
So yes, death to the false meme that we are ruining the planet, as vector to massive government control of the economy, with attendant slowing of it.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
I did not know it was such a precious commodity...seems legit.
Judging by the comments, who would have thought the population of slashdot is 50% luddites. Seriously, this is why you start on small asteroids. A 2m rock is going to burn up in the atmosphere.
It doesn't have to hit Earth to affect it. Consider the tides. Our global eco system has evolved to expect tides. It would be difficult if not impossible to predict the full extent of the harm that could result if tidal patterns are altered. All sorts of life could flourish or die under such changes.
I'm not exactly a tree-hugger, but I certainly appreciate the factors and influences over life on this planet. This would affect the oceans in all sorts of ways. That which affects the oceans and the life within them will affect us and possibly even global weather patterns.
Because a 2~60m diameter stone in space can significantly alter tides.
The level of numerical illiteracy* of the general public (i.e. the GP) is appalling, and combined with the boatloads of self-esteem fed to them during school years, it resulted in people worse than being totally ignorant.
A totally ignorant person would either ask the above question without assumption, e.g. "Is it possible for the captured asteroid to affect the Earth in any meaningful way?", or just assume the experts have already thought about it. Only those who knew just enough to be dangerous would both assume their imagination (considerations that is not based on hard facts nor experience is no different than imagining things) is correct, AND the experts have not considered it already.
* - by that, I mean the lack of sense in numerical scales and numbers. The radius of the Moon is in the order of ~1000km, so a 60m asteroid (round to 100m) is 4 orders of magnitude in linear dimension and thus 12 orders of magnitude in volume. How lack of numerical sense do you need to be to think that something 12 orders of magnitude smaller can have any impact?
Thank goodness, a level-headed, rational viewpoint.
Come have a beer with me - drive your 100.00000000000000% reliable and totally safe car to my neighborhood.
I'm just glad you used the back of a napkin and not a piece of toilet paper...
that many of them i'd expect them to be largely equally spread out, or near enough to be considered such. as such, the effect would be close to nil, and the net effect would be zero. note also that this entirely ignores the problems of keeping a few thousand (or hundred thousand!!) objects orbiting the earth at tens of thousands of miles per hour without colliding, which they surely would, quickly forming a problem many orders of magnitude in excess of the current problems with space junk.
in other words, the tidal effect is both neglible and not the primary concern in that scenario.
The guy who said the election was rigged won the presidency with the second-most votes.
We are not just collecting them, the plan is to mine them. And what's this talk about hundreds or thousands? Even if asteroid mining becomes an industry, i doubt there will be more than 10 at a time. Eventually, they will learn to mine them on spot or use the Moon for it, without towing them to Earth.
Patents Drive Free Software as Hurricanes Drive Construction Industry
i think you should be taking your own advice.
one thing you forgot to consider was distance, and the moon si really really far out there.
also, 12 orders of magnitude is 10^12. given that the moon is ~3474km in diameter (1700km radius), compared to a 60m object the moon is only 5.79e+4 times larger....which is no where near "12 orders of magnitude". but the size that we really need to consider isnt dimensional anyway, but mass.
so let's explore:
Remember the formula is F=G*m1*m2 / d^2. The gravitational force is inversely proportional to the square of the separation distance between the two. So we can hold the factors other than d unitary to determine the relative strengths at the following distances (truncated for space):
~380k km (roughly the moon's average distance) = 6.925e-12
~36000 km (typical geosynchronous orbit, ie, GPS) = 7.716e-10
~2000 km (medium earth orbit) = 2.5e-7
So an object at MEO has 324x as much pull as the same object at typical geosynchronous distance, and >36000x as much pull as the same object at the moon's distance. So an object the size of the moon at the moons distance can have the same pull as an object 1/36000 the mass of the moon but in MEO*. Given the moon's mass is 7.3477e+22 kg, this gives us an equivalent mass of 2.041e18 kg at MEO, or 2.26e+20 kg at geosynchronous distance**. Then we can take the moons density of ~3346 kg/m^3. This gives us volumes of ~6.0998e+14 m^3 (MEO) and ~6.754e+16 m^3 (GS), which in turn give shperical diameters of 105.22 km (MEO) and 505.27 km (GS).
So we end up with objects only 0.0302 and 0.1454 the diameter of the moon at MEO and GS to have the same effect as the moon, assuming the same density as the moon. If we instead assume say an asteroid largely composed of Iron (density 7,870 km/m^3) we get diameters of ~79 and 380 km. An iridium asteroid is about the densest thing we might find out there, and even then our diameters calculate to ~56 and ~268 km.
So this is neat stuff, and now we get a real sense of what it would take to have an effect equivalent to the moon. But that's not to say there would no effect. while the distance relationship is an inverse square, the effect of mass is directly proportional, so something with half the mass will have half the effect. and while the poster mentioning hundreds of thousands of these things misses the logistical problems, having a sufficient number number of solid or metallic core examples of these things could have a measurable impact, particularly in terms of periodic reinforcement. and now im running out of time for thought experiment math (gotta get back to work).
*(force vector going to center of a theoretical main body, and thus ignoring for now the angles of distributed force vectors in the real situation being far different between an object in MEO and an object at the moons distance as they effect a fluid on the surface of said main body)
**(ignoring for now the orbital velocities or distances required for such objects to remain in stable orbit)
The guy who said the election was rigged won the presidency with the second-most votes.
And if it were a sphere of neutronium only 60m diameter, I suspect it wouldn't remain neutronium for very long either.
My first guess is that if such an object somehow blinked into existence, it would instantly become a rapidly expanding sphere of plasma and gamma rays.
I can see the fnords!
If the Kerbal Space Program has taught me anything, it's that all space problems can be mitigated with the clever use of more rockets.
I read TFA and all I got was this lousy cookie
Then let me finish for you. Given the numbers you calculated, the biggest object, with the highest reasonable density, in the closest orbit, would have one billionth the effect of the moon (60m vs 56km, cubed). So, in a place like the Bay of Fundy, with some of the largest tides in the world (16m), you still couldn't measure the difference with a ruler.
Sure I'm paranoid, but am I paranoid enough?
Your a bunch of pussies 1. the asteroid sizes they're talking about would have no significant affect in any failure scenario, well perhaps if it actually HIT the ISS or a satellite but thats not likely. The size of asteroids they want to mine would almost entirely burn up in the atmosphere if it did miss and enter earth.
This is the exact thing we need to be doing we cant exist on earth forever, even if we had 0 environmental impact as a race the planet would eventually expire. Exploiting extra-planetary resources and colonizing space are the most important goals that could ever exist for us as a race. Only those things can provide us a chance at keeping the human race alive in perpetuity
You know, that sounds like something that would significantly alter the tides.