Retrieving an asteroid

Dec 27, 2013
An image of the asteroid Tempel 1 taken during the Deep Impact visit. Tempel 1 is about five kilometers across. CfA astronomers have estimated the size of the smallest measured near Earth asteroid, 2009 BD, as only about three meters across, perhaps too small for it to be useful in NASA's planned asteroid recovery mission. Credit: NASA/JPL-Caltech/UMd

(Phys.org) —Asteroids (or comets) whose orbits bring them close to the earth's orbit are called near Earth objects. Some of them are old, dating from the origins of the solar system about four and one-half billion years ago, and expected to be rich in primitive materials. They are of great interest to scientists studying the young solar system. Others, of lower scientific priority, are thought to contain minerals of potential economic value.

NASA has announced its interest in sending a manned mission to a near Earth object. The NASA Asteroid Robotic Retrieval Mission concept involves the capture of an asteroid, and dragging it onto a new trajectory that traps it in the Earth–Moon system where it will be further investigated by astronauts. The current mission design requires the target asteroid to have a diameter of seven to ten meters. The object NEO 2009BD is a prime candidate for this retrieval mission. It was discovered on January 16, 2009, at a distance from the Earth of only 0.008 AU (one AU is the average distance of the Earth from the Sun). Its orbit is very Earth–like, with a period of 400 days, and it will end up close to the Earth–Moon system again in late 2022 when the proposed capture would take place. It seems to be a perfect candidate, with a time frame that allows for proper mission planning.

The problem is that the size of the NEO 2009BD is uncertain, and thus its density and composition are also uncertain, but first estimates are that it likely falls in the diameter range specified by the mission. The uncertainty arises because it was detected at optical wavelengths; they measure reflected light, which is a combination of both an object's size and reflectivity (albedo). For NASA mission planning to succeed, a more direct size measurement of 2009 BD is needed—and soon, before its increasing distance from the Earth makes such an observation a practical impossibility.

CfA astronomers Joe Hora, Howard Smith and Giovanni Fazio have been regularly using the IRAC camera on the Spitzer Space Telescope to measure the infrared emission of near Earth objects, and (with some modeling) deriving both the sizes and densities of these objects. They received special observatory time to study NEO 2009BD, and in an upcoming issue of the Astrophysical Journal they and their colleagues report on their conclusions. They did not detect the NEO 2009BD to a very low light level, implying that it is very small, probably only about 2.9 meters in diameter, and modeling suggests it has a rubble-pile composition. This is the smallest object ever reported on by Spitzer; whether it is still suitable for a NASA mission is now something that the NASA Retrieval Mission team must determine.

Explore further: Asteroid hunter spacecraft returns first images after reactivation

More information: "Constraining the Physical Properties of The Near–Earth Object 2009 BD," M. Mommert,J. L. Hora,D. E. Trilling,S. R. Chesley and D. Farnocchia,D. Vokrouhlick´y, M. Mueller,A. W. Harris, H. A. Smith and G. G. Fazio, ApJ, 2013, in press.

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Returners
1 / 5 (14) Dec 27, 2013
Retrieving something that small would be a waste of time.
Doug_Huffman
1.4 / 5 (9) Dec 27, 2013
How small is "that small?" Tempel 1 is ~7.5E13 kG.

A better question is, do you trust Joe Shiite the Ragpicker to not screw-up and drop it on your head. Can he loft sufficient delta-V to correct his "Ooops!"?
Returners
2 / 5 (13) Dec 27, 2013
How small is "that small?" Tempel 1 is ~7.5E13 kG.

A better question is, do you trust Joe Shiite the Ragpicker to not screw-up and drop it on your head. Can he loft sufficient delta-V to correct his "Ooops!"?


I was referring to the 3 meters rock they describe at the end of the article.

In order to be useful for both scientific and domestic reasons, it needs to be large enough to represent the sort of objects we'd like to mine precious metals and rare earths from, when the technology and infrastructure becomes available.

Ironically, the gold and platinum, and other heavy, rare earths or precious metals would most likely be near the core of a differentiated object, so the size range that is practical for mining needs to be large enough for the find to justify the costs, but small enough for the resources to be harvested without drilling through miles of metals.
TheGhostofOtto1923
4 / 5 (10) Dec 27, 2013
In order to be useful for both scientific and domestic reasons, it needs to be large enough to represent the sort of objects we'd like to mine
Well obviously this can't be true because real scientists and engineers are the ones proposing the above mission. You must either be mistaken or not well-enough informed about what they want to do and why they want to do it.

Or perhaps you don't really care and would rather guess and make shit up because it feels better and it is after all a lot easier.
Returners
2.2 / 5 (17) Dec 27, 2013
Ghost:

You're an idiot.

If it was really just about taking samples from a rock, we already have any number, tens of thousands, of remains from meteorites.

It's supposed to be a proof of concept mission, not just some sample-taking.
ViperSRT3g
5 / 5 (7) Dec 27, 2013
The current mission design requires the target asteroid to have a diameter of seven to ten meters.


The asteroid mentioned above is approximately 3 meters in diameter. It's only a third of the size that this mission would like to target. That is why this asteroid is only a proposed target.
nkalanaga
4.3 / 5 (7) Dec 27, 2013
I like the idea of retrieving a small rock first for several reasons:

It's cheaper than fetching a big one. If it fails we haven't wasted as much money.
If it works, we can then scale-up the technology for a bigger one.

It's safer. If we misplace a decimal point and the thing hits Earth it won't do much damage. Dropping a big one could get messy.

However, if NASA specifically wants a 7 to 10 m rock, then yes, 3 m is too small.
DeadCorpse
4 / 5 (8) Dec 27, 2013
My main point of interest is why it seems to take NASA 10+ years to do anything...
Shootist
1.8 / 5 (5) Dec 27, 2013
My main point of interest is why it seems to take NASA 10+ years to do anything...


The shuttle cost $2 billion a year whether it flew or not. NASA has had a bureaucracy that is more interested in furthering the organization than pursuing the mission since the late seventies. Look to Feynman's appendix, read what he said, then to the results from Columbia.
TheGhostofOtto1923
3.7 / 5 (6) Dec 27, 2013
You're an idiot.
Im not the one here pretending to be a scientist and posting nonsense.
It's supposed to be a proof of concept mission, not just some sample-taking.
How would you know? Youre not a scientist. You think proof of concept requires returning halleys comet.

Obviously real scientists think that returning something a lot smaller is necessary for proof of concept. Perhaps you might want too do a little research to try to understand 'why'.
Returners
1.9 / 5 (14) Dec 27, 2013
How would you know? Youre not a scientist. You think proof of concept requires returning halleys comet.

Obviously real scientists think that returning something a lot smaller is necessary for proof of concept. Perhaps you might want too do a little research to try to understand 'why'.


We already know what the rocks are made of as we have thousands of samples of the damn things, and returning a 3 meter rock doesn't prove anything.

I never said anything about Haley's comet or any other really large object, but if you want to keep being a fricken idiot, and a liar, for the rest of your life, go right ahead. Nobody's stopping you, and I doubt you'd heed them anyway if they tried.
TheGhostofOtto1923
4 / 5 (4) Dec 27, 2013
We already know what the rocks are made of as we have thousands of samples of the damn things
See, this is why it is so easy to tell that you have no idea what you are talking about.

"[asteroids are] expected to be rich in primitive materials. They are of great interest to scientists studying the young solar system. Others, of lower scientific priority, are thought to contain minerals of potential economic value."
I never said anything about Haley's comet or any other really large object
-What you said was:
near the core of a differentiated object, so the size range that is practical for mining needs to be large enough for the find to justify the costs
-And we find that:

"the differentiation of asteroids in particular forms an end member in understanding large-scale igneous processes. In comparison to Earth, asteroidal differentiation occurred at much
lower gravity (radii ≤ 500 km)..."

"Halleys comet Dimensions 15×8 km, 11 km (mean diameter)

-So. You done yet?
TheGhostofOtto1923
3 / 5 (2) Dec 27, 2013
The internet is the enemy of all bullshit artists. Well, all incompetent bullshit artists that is.
Captain Stumpy
5 / 5 (4) Dec 27, 2013
@Returners

and returning a 3 meter rock doesn't prove anything.


IMHO - returning this rock would allow a lot of testing and theory development that would then be scalable.
it would also demonstrate feasibility.
it would be easier than attempting a larger rock, and therefore more likely to succeed. (we have never done this before).
cost would be less than larger targets.
it may also teach us about which technologies are not a good idea.... from different mechanisms of thrust to securing it into orbit.
IOW: proof of concept.

it seems to me to be a great start.
antialias_physorg
5 / 5 (2) Dec 27, 2013
In order to be useful for both scientific and domestic reasons,

We're not talking 'domestic' reasons here. If mining comes into this at all it'll be as a test object: to see what kind of appartus would need to be developed to get through something of similar composition effectively in zero g. The samples we have on Earth are too small to say whether what's out there is mostly homogeneous or very heterogeneous. 10m diameter would be preferrable, But looking at the mission parameters (max distance, max relative speed, etc. ) finding such an optimal candidate would be extremely lucky.

As with everything you have to start small and then work your way up.
davidivad
2.3 / 5 (3) Dec 27, 2013
i am glad to see us doing something new.
Returners
1.5 / 5 (11) Dec 27, 2013
"the differentiation of asteroids in particular forms an end member in understanding large-scale igneous processes. In comparison to Earth, asteroidal differentiation occurred at much
lower gravity (radii ≤ 500 km)..."

"Halleys comet Dimensions 15×8 km, 11 km (mean diameter)



Wow. You have no sense at all. I didn't imply that at all.

There are other types of objects besides planetesmals, including much smaller objects which are cast-off from prior collisions.

As for the composition of the asteroids, the evidence from meteorites shows that no two of them are exactly the same, or necessarily the same at all. Google "Meteorite Cross-section" for a few scores of pictures of them, and you'll see what I mean.

From the perspective of any potential mining operations, it is almost certainly not practical to go chasing down 3 to 10 meter diameter rocks to mine from, unless you, by chance, notice that one of them is made of solid gold or some other absurdly unlikely scenario.
Zephir_fan
Dec 27, 2013
This comment has been removed by a moderator.
Returners
1 / 5 (11) Dec 27, 2013
Skippy, I'm not a scientist even though a lot of peoples mistake for one, I use the google is why. So I'm thinking what the other smart peoples said makes sense to me. Maybe they need to start with a little one first just learn how to do it? I mean, you wouldn't want a doctor to do a heart transplant on you his first time out would you? Or an engineer wannabe type to build a Brooklyn Bridge without practicing something smaller first would you?


I didn't say they shouldn't start with a little one, but you have to admit a few meters is a joke.

The Russian meteorite fragment they found from that lake is about that big. it would be an insane waste of time and money to retrieve an object no bigger than what we've already retrieved from a recent impact.

I'm thinking 10m is a bare minimum, and maybe need something more like 50 meters.

I'm interested in how different elements might migrate in the interior when they formed; relevance cost of mining specific elements.
Zephir_fan
Dec 27, 2013
This comment has been removed by a moderator.
Mimath224
2.3 / 5 (3) Dec 28, 2013
@Zephir_fan, I like your modesty but I think you're keeping something between the lines. '...without practicing something smaller first would you?...' Dead right! If a small village bridge breaks up it will only injure a few. After all one would a bridge to be well used to test it eh? Haven't we got enough rubbish in orbit already...but wait...the captured rock wouldn't be rubbish would it and even that exercise itself is worth doing. And what a splendid way to break it up so that it gives am.astro's can skywatch a man made shower...sorry about that I'm just a suspicious guy, you know, accident or intent!?
What I would like to see is a mission to one the larger asteroids, not coming our way, landing, collecting samples and bringing them back to the ISS...but that would cost a lot, I guess.

EnricM
1 / 5 (1) Dec 28, 2013
My main point of interest is why it seems to take NASA 10+ years to do anything...


Just wait for the Chinese
davidivad
1 / 5 (1) Dec 28, 2013
yea, let them pull a rabbit out of their hat.
Returners
1.1 / 5 (13) Dec 28, 2013
My main point of interest is why it seems to take NASA 10+ years to do anything...


Capitalism, of course.

"Somebody" always has to make two or three times more money off a program than what it's really worth, whether it's the contractors or a supplier, or a kickback to some lobbyist organization.

Take the JWST; As I understand, it's now something like twice above it's original budget, and approaching three times now?

What is one to conclude, except one of two possibilities:

Either someone is or was incompetent in the estimates of the costs, OR someone is corrupt and making a ton of money, laundering money from the project to their own accounts or projects, or to their buddies' projects. There is the possibility that the money is being funneled to a so-called "Black Project," but that seems unlikely, since Black Projects actually cost even more money than the amount in question.

So which is it? Corruption, or incompetence?
TheGhostofOtto1923
3.7 / 5 (6) Dec 28, 2013
The Russian meteorite fragment they found from that lake is about that big. it would be an insane waste of time and money to retrieve an object no bigger than what we've already retrieved from a recent impact
-So whose opinion should we trust ? Scientists who are actually working in the project and who have decades of training and experience or someone who wants to drill
near the core of a differentiated object, so the size range that is practical for mining needs to be large enough
-but doesn't realize he is referring to objects 1000km in diameter... And then thinks halleys is that big -?
Wow. You have no sense at all. I didn't imply that at all
-Well now you're just lying aren't you?
Capitalism, of course
-So you seek refuge in political posturing. A typical ploy of bullshit artists. NOBODY can prove you wrong there can they?

So... you done yet picasso?
Zephir_fan
Dec 28, 2013
This comment has been removed by a moderator.
Returners
1.4 / 5 (10) Dec 28, 2013
Otto:

You've been reported for falsely representing my statements, repeatedly, since I corrected you, and you keep lying about it anyway.

I shouldn't expect any different from you anyway, and it's a mystery to me why the sites admins never ban you, when they ban other people for far lesser offenses than what I've seen you do.

Piss off, loser.
Zephir_fan
Dec 28, 2013
This comment has been removed by a moderator.
TheGhostofOtto1923
3.7 / 5 (3) Dec 28, 2013
You've been reported for falsely representing my statements, repeatedly, since I corrected you, and you keep lying about it anyway
Reported to who? Mossad? Your mom? Someone who knows what the term 'differentiated' means before they use it to comment about a subject they know nothing about?

Sorry but when I read ignorance like
Retrieving something that small would be a waste of time
-I just have to speak up.
Mimath224
3 / 5 (2) Dec 28, 2013
@TheGhostofOtto1923, I guess via the 'report' next to 'quote'? A good point, to whom does such a 'report' go to? Since I am new here I'm just asking.
davidivad
1 / 5 (1) Dec 28, 2013
it would seem to me that you would want to get paid for your effort. that must be where all this ingenious scientific ideology comes from. an education gives you something that google does not. that would be the professional stances and viewpoints of the field. most of the links here with a lot of information sound like freshly graduated students and not people with any kind of real supported experience. it would be my guess that these individuals have no place on sites that require math or professionalism. the first thing i ask about a thread is whether or not it has new ideas based on time tested references, can be mathematically proven, and adds significantly to the body of knowledge. of course i still love reading the stupendous arguments on this site. it makes me feel smarter. just remember guys, when you start coming up with complexities you are probably missing something simple. K.I.S.S.
antialias_physorg
5 / 5 (3) Dec 29, 2013
A good point, to whom does such a 'report' go to?

It goes to the people at physorg.
Seeing there are only a handful of people running this site I can't see that this gets much attention, though - as the amount of moderation has certainly dropped to (near) zero over the past couple of years.

But it certainly is better than nothing. In extremem cases physorg reacts to this rather quickly (e.g. for spambots with advertising links embedded in their 'posts')
Old Guy in Stanton
3 / 5 (4) Dec 29, 2013
Retrieving something that small would be a waste of time.

Retrieving something that small would be a waste of time.


Baby steps...... It is only in Space Opera[*] that scientists go for broke on new technology, rather than testing small steps. though more expensive in money and time, it helps keep them from running through too many astronauts.

[*] Skylark of Space series by E. E. Smith comes to mind. Unless you're a Norlaminian, it is probably a bad idea to just put together a complex system without testing out every single step, phase and part.
Old Guy in Stanton
2.3 / 5 (3) Dec 29, 2013
"According to the fan mail I receives, Otto and I are tied in the top spot of click generated counts. ......."

The counts? Seriously? So is that why all of your posts on every thread read like they were written by a friendless, Cheetos-eating, living-in-Mom's-basement, forever-alone moron?
Zephir_fan
Dec 29, 2013
This comment has been removed by a moderator.
Old Guy in Stanton
2.3 / 5 (3) Dec 30, 2013
"According to the fan mail I receives, Otto and I are tied in the top spot of click generated counts. ......."

The counts? Seriously? So is that why all of your posts on every thread read like they were written by a friendless, Cheetos-eating, living-in-Mom's-basement, forever-alone moron?


Plagiarizing is disallowed Skippy. So knock it off. You can put the pointy cap on your head now. (And when you turn back into the nounemom, I expect to see it there still on your head.)


Yep, you're a bot.
Mimath224
1 / 5 (1) Dec 30, 2013
Yep, you're a bot.

The counts? Seriously? So is that why all of your posts on every thread read like they were written by a friendless, Cheetos-eating, living-in-Mom's-basement, forever-alone moron?


Piss off, loser.
So... you done yet picasso?

I gotta hand it to you guys, there almost as much 'name calling' as there are types of space rocks ha!
...composition of the asteroids, the evidence from meteorites shows that no two of them are exactly the same...
That made me wonder; to which do you refer, the Met. or the Ast parent?
Way back last century, just as an example, BAG types were considered not only to have come from perhaps more than one Ast but could come from a single AST depending on it's size which would determine whether certain reactions continued of stopped at a certain point.
Chondrite protoliths might also be affected by gas which might overcome graviatational effects of the parent Ast. cont...
Mimath224
1 / 5 (1) Dec 30, 2013
cont. But there is still a need to examine met and it's parent but this requires a whole program of missions. I wonder if we can afford it?
GSwift7
5 / 5 (3) Dec 30, 2013
wow, I really want to make some serious comments, but the thread has sunk really low.

I can see some merrit to capturing a small 'rubble pile' type asteroid. We really don't understand much about these yet. However, there's already quite a bit of planning and concept development underway, and both the small size and the rubble pile composition would require revisions to the core of the mission concept. You would need to go all the way back to a clean sheet of paper really.

As I understand it, what we really want to grab is a condrite type asteroid of the largest size we can reasonably handle. The condrite type is intersting due to the fact that we only have bits and pieces of them here on the ground, and the interesting parts of them are likey destroyed (water and organics, for example).

The size is important because if it's too small, then even the interior may not be preserved well enough to contain pristine primordial materials. 10 meters is more likely to be sealed up inside.
GSwift7
4.3 / 5 (6) Dec 30, 2013
BTW, Otto:

There are a range of different opinions of what goals are most important, in regard to asteroid exploration. Ideally, we would like to explore all the different types and a range of sizes as well. The mission concept mentioned above is derived from a range of different options with a number of off-setting pro's and con's to each of the different possible missions.

In terms of proof of concept and such, a rock only 3 meters accross really doesn't meet the needs of some of the experiments we would like to try out. For example, a 10 meter rock will have just enough of its own gravity to give us useful practical experience in working around similar, but larger objects (phobos maybe?). A three meter rock is so small that it really doesn't work for practice missions. Part of the idea of capturing a 10 meter rock is so that we can do practice missions on it, similar to how we practice space walks in swimming pools. It would be a place to test tools and procedures.
GSwift7
4 / 5 (5) Dec 30, 2013
continued:

So, Otto, in regard to your disrespectful tone towards people suggesting alternative mission concepts. They are not wrong to suggest alternatives, see as how those very alternatives were among the choices originally considered by NASA while planning this mission. Some of those options are still on the table, as a matter of fact. There are other good targets in near Earth orbits, so if the one mentioned in this article is less than ideal, then they may choose another target in stead. On the other hand, if those other potential targets just aren't as easy as this one, then they may change the mission and grab this small rock simply because it's so easy to get and the timing is right.

It's okay to talk about these things, even though we aren't sitting at the NASA planning meetings, and we aren't mission planners or anything.

In stead of blasting someone for throwing out some casual comments, try adding to the conversation in stead of being anti-social all the time.
rwinners
not rated yet Dec 30, 2013
Someone is going to try this. I do hope they get it right EVERY time.
TheGhostofOtto1923
3 / 5 (2) Dec 30, 2013
a rock only 3 meters accross... a 10 meter rock will have just enough of its own gravity to give us useful practical experience... blah
THIS is what NASA is considering:

"The NASA officials emphasized that the asteroid redirect mission is still in the planning phases. Muirhead said the agency hadn't decided whether it would go after a small asteroid about 20 to 30 feet in diameter... or instead try to rip a boulder off a larger asteroid and bring the piece back to Earth."

10 meters = 30ft = 0 gravity. A rock 1/3 that size has the same amount.
So, Otto, in regard to your disrespectful tone
1) Mind your own business

2) Saying that scientists are wasting their time, and then saying that we need to capture a 'differentiated object' without knowing that these things are radii ≤ 500 km, displays a profound disrespect for both science and the facts. And so I responded in kind.

You yourself have shown similar disregard for facts as I recall.
TheGhostofOtto1923
3 / 5 (2) Dec 30, 2013
For instance:
A three meter rock is so small that it really doesn't work for practice missions.
-See? A little research would tell you exactly what 'we' are planning to do at this point in time. I cant BELIEVE anyone would have the audacity to make shit up, knowing that it only takes a minute to find the FACTS.

More:
have just enough of its own gravity to give us useful practical experience in working around similar, but larger objects (phobos maybe?)
Phobos - mean radius of 11.27 kilometers; gravity = 1/1000th as strong as it is on the Earth... But it is still way more than zero, which is the amount of gravity a bus-sized rock would effectively have.

This is the internet. I suggest you use it.
rwinners
not rated yet Dec 30, 2013
Hmmmm what would Phobos it accidentally whacked the earth.... or the moon?
Zephir_fan
Dec 30, 2013
This comment has been removed by a moderator.
rwinners
not rated yet Dec 30, 2013
So some wants too take a chance of whacking the world and humanity.... Not good.
Zephir_fan
Dec 30, 2013
This comment has been removed by a moderator.
GSwift7
not rated yet Dec 31, 2013
displays a profound disrespect for both science and the facts. And so I responded in kind


No, you're just being antisocial, as usual.

See? A little research would tell you exactly what 'we' are planning to do at this point in time. I cant BELIEVE anyone would have the audacity to make shit up


lol, and if you actually go a bit farther into the subject than the first couple of links on Google, you may find that the truth is a bit more grey than black and white. The 'mission plans' are just options. The ones currently selected are not the only mission plans, and what finally happens depends a lot on what kind of asteroid they grab, and size is an important part of that.

But it is still way more than zero, which is the amount of gravity a bus-sized rock would effectively have


Demonstrating ignorance when you could have just shut up. A 10 meter rock has enough gravity to have dust suspended around it, which is an important thing for us to learn how to work with.
GSwift7
5 / 5 (1) Dec 31, 2013
As for terrorists or rogue states ever using an asteroid as a weapon, or an accidental human-caused impact, that's really just bubblegum fiction stuff. While it is technically possible, there are a number of reasons you don't need to realistically worry about it.

For now, there are many cheaper, faster and more certain ways to do that much damage or more. Heck, a simple fuel-air bomb might do more damage, and it would definitely be more accurate.

Also, there's no way anyone could do all the work needed to move a really big asteroid without everyone else seeing them doing it. It's absurdly easy to stop them before they get it done (sabotage their launch pad, for example).

Accidental impact, like if NASA lost control of a rock, is absurdly easy to avoid. Simply use a fail-safe vector any time you move one. Besides, roids large enough to be really dangerous take time to move. You can't just make a one-second mistake that would end in doom; it takes a long time to accelerate that mass.
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
you may find that the truth is a bit more grey than black and white. The 'mission plans' are just options
"The NASA officials emphasized that the asteroid redirect mission is STILL IN THE PLANNING PHASES. Muirhead said the agency HADNT DECIDED whether it would go after a small asteroid about 20 to 30 feet in diameter... OR instead try to rip a boulder off a larger asteroid and bring the piece back to Earth."

-I don't know g that sounds pretty grey to me. And from the article

"The current mission design requires the target asteroid to have a diameter of seven to ten meters."

"For NASA mission planning to succeed, a more direct size measurement"

-See, they need to start matching potential targets with their projections on what the tech will allow them to do. Which according to them is something "small asteroid about 20 to 30 feet in diameter... or instead try to rip a boulder off a larger asteroid" -also in that general size range for THIS specific mission.
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
Hey did you reconcile that gravity notion (bullshit) of yours with the FACT that 10 meter objects have no effective gravity? The ISS has more gravity than that. Mir had more gravity than that. A Saturn V had more gravity than that! Lol

Hey here's some asstronauts doing gravity experiments
http://youtu.be/rOrzKtEW0xg
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
As for terrorists or rogue states ever using an asteroid as a weapon, or an accidental human-caused impact, that's really just bubblegum fiction stuff
You may not know it but real scientists have actually examined the potential. And they're on the internet too! Who woulda thunk it-
http://www.theliv...pon.html
there are many cheaper, faster and more certain ways to do that much damage or more
Robotics and AI will quickly change this. Fissiles refining will always be high profile.
Heck, a simple fuel-air bomb might do more damage
Bullshit. Look it up. Look up Arizona crater.
Cont>
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
Also, there's no way anyone could do all the work needed to move a really big asteroid without everyone else seeing them doing it
-You mean like building reactors and centrifuge facilities out in the desert?
It's absurdly easy to stop them before they get it done (sabotage their launch pad, for example).
Asteroid mining programs will be legal for any capable nation as reactors are now. And asteroids being moved into accessible orbits by robots will be as ambiguous as reactors are now. And after the tech is launched it is too late to destroy the pad yes?
absurdly easy to avoid. Simply use a fail-safe vector any time you move one
And impact vectors are absurdly easy to disguise as mining recovery operations until it is too late to stop them.
GSwift7
3.7 / 5 (3) Dec 31, 2013
Otto, why do you get so bent out of shape?

Hey did you reconcile that gravity notion (bullshit) of yours with the FACT that 10 meter objects have no effective gravity? The ISS has more gravity than that. Mir had more gravity than that. A Saturn V had more gravity than that! Lol


That is incorrect. A ten meter or larger asteroid will have enough surface gravity to cause noticable effects. For instance, dust kicked up from digging, cutting, drilling, etc. should tend to stick around the vicinity. There's not enough gravity for a person to stand, but there may be enough to be useful or be a problem in some ways. For example, it might be enough for a solid state gyroscope to function near the surface, which might be helpful for some tasks that require orientation of instruments. It isn't much gravity, but it's enough to teach us a few things about working in extremely low, but not micro gravity situations, and design tools that take advantage of it.
GSwift7
3 / 5 (2) Dec 31, 2013
The reason the ISS is different is because of density. All the mass of an asteroid is concentrated in one place, with a high densit, which gives you a short radius from the center of gravity to the surface. The ISS or a Saturn V rocket is nowhere near that dense, and inside the ISS you'll have the minimal gravity of the station pulling in multiple directions, which gives a net pull of nearly zero. The ISS's mass is spread out over such a large volume, that by the time you get far enough away so that all of its gravity is basically pulling in the same direction, you're too far away to feel it.

This is fairly simple to work out on paper. Since the principle works the same in two dimensions as it would in three, the vector math is straightforward.

The crater in AZ was formed by an object more like 50+ meters, made of iron/nickle. It would take a 100+ meter stony roid to do the same damage. 10-20 meter roids don't even make it to the ground most of the time.
GSwift7
3 / 5 (2) Dec 31, 2013
And impact vectors are absurdly easy to disguise as mining recovery operations until it is too late to stop them


Holy sci-fi alert Batman!!!

It's always just a matter of time before you start throwing in stuff from Ben Bova novels or some such. Let's stick to what's real. Oh wait, it's on the internets, isn't it? It must be real then.

And no. Nobody is going to launch enough equipment into space to manage the job of moving a 50+ meter asteroid into an earth impact trajectory without the world's governments finding out about it. You can't go up without someone spotting you these days, and it's fairly easy to see when somebody goes up beyond LEO. There are a lot of eyes watching that stuff.

You do realize that it would take several launches to get that much gear to the main belt, right? There are scarce few asteroids that large in near earth orbits that also have inclinations that would make such a project feasible, so to get a 'killer' roid you're going to the belt.
TheGhostofOtto1923
2.3 / 5 (3) Dec 31, 2013
For instance, dust kicked up from digging, cutting, drilling, etc. should tend to stick around the vicinity
No it wont.
For example, it might be enough for a solid state gyroscope to function near the surface, which might be helpful for some tasks that require orientation of instruments
???? What do gyros have to do with gravity?
The reason the ISS is different is because of density. All the mass of an asteroid is concentrated in one place, with a high densit, which gives you a short radius from the center of gravity to the surface
Wow you almost sound like a scientist. What does the 5 meter distance to the center of an asteroid have to do with it having absolutely NO gravitational effect whatsoever on you? Does this mean that since we are a few 1000 miles from the center of the earth we should be weightless??

YOU are full of SHIT.
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
crater in AZ was formed by an object more like 50+ meters
-And you didnt bother with the link I posted

"Feasibility of diverting asteroid 1981 Midas... Only about 301.5 mps will cause the asteroid to shift into a collision course...
Midas' diameter: 3.4 kilometer..."
10-20 meter roids don't even make it to the ground most of the time
They dont have to:

"Tunguska event... 60 m (200 ft) to 190 m (620 ft)... between 10–15 megatons of TNT"

"The Chelyabinsk meteor was a near-Earth asteroid that entered Earth's atmosphere over Russia on 15 Feb 2013 ... dia about 17–20 meters and final mass est 10,000 tonnes... total kinetic energy before atmospheric impact equivalent to approximately 500 kilotons of TNT... many large fragments recovered..."

"collision between a planet and an asteroid a few kilometers in diameter may release as much energy as several million nuclear weapons..."

Impactor - 100 meter dia.; energy 47 Mt; crater dia. 1.2 km (0.75 mi); frequency 5200 years
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
just a matter of time before you start throwing in stuff from Ben Bova novels
Like I say, you should have looked at the link I posted.

"Diverting the course of an asteroid requires only a small DeltaV, if the deflection is done far enough in advance of earth impact. The displacement is proportional to both the lead time and DeltaV.1 Done well in advance... requires imparting a DeltaV of at least several tens of meters per second to the asteroid." -RAND Corporation

"It has been estimated that a velocity change of just 3.5/t × 10−2ms−1 (where t is the number of years until potential impact) is needed to successfully deflect a body on (or onto) a direct collision trajectory..."

Ways of doing this robotically:
Gravity tractor
Kinetic impact
Ion beam shepherd
Focused solar energy
Mass driver
Rocket engine
http://en.wikiped...voidance

-All of which could be disguised as mining recovery headed for a near-earth location.
TheGhostofOtto1923
3 / 5 (2) Dec 31, 2013
And no. Nobody is going to launch enough equipment into space to manage the job of moving a 50+ meter asteroid into an earth impact trajectory without the world's governments finding out about it
Recovering and mining space objects as I say will be the right of any nation. Iran is sending monkeys into space. In 50 years many nations and private interests could be sending robotic ion drives or mass drivers out in search of mineral wealth and there is nothing anyone could or would do to stop them. There will be an existential threat not only to earth but to satellites, orbital stations, and outposts on the moon and other planets.
Returners
1.5 / 5 (8) Jan 01, 2014
Heck, a simple fuel-air bomb might do more damage


Haha.

How wrong you are.

Of course, for relatively small objects in the 10 to 50 meter range, it really depends on the altitude the object is at if and when it turns into an air burst. We know if the Russian object earlier this year had been perhaps a half kilometer or so closer to the surface when it exploded it could very well have killed tens of thousands of people. AS it was, it was right at the boundary of becoming a mega-disaster, with over a thousand direct injuries, including ear drums blown out, plus structures severely damaged and destroyed, including reinforced masonry buildings in a few cases.

This was not a large object at all in comparison to typical Asteroids and Comets in the solar system. In fact, it was very small compared to any number of known objects.

If something the size of Meteor Crater happened in modern times it would be the worst human disaster ever. It might kill a billion or more people.
TheGhostofOtto1923
2.3 / 5 (3) Jan 01, 2014
If something the size of Meteor Crater happened in modern times it would be the worst human disaster ever. It might kill a billion or more people
-And that's almost everybody in the entire US haha

Jeez what if it hit yellowstone ??!?!! OMG
Returners
1 / 5 (5) Jan 01, 2014
If something the size of Meteor Crater happened in modern times it would be the worst human disaster ever. It might kill a billion or more people
-And that's almost everybody in the entire US haha

Jeez what if it hit yellowstone ??!?!! OMG


I'm talking about climate changes and damage to food supply. I don't know what your problem is, but I've seen estimates of what these things can do, but maybe earlier poster was disregarding the dangers.

As you well know, for these types of disasters the total damage is not limited to the physical damage or trauma caused on the first day from the impact itself. More damaging are secondary disasters like blocking out the sun, and flash forest fires which destroy entire ecosystems in the following hours and days.

Obviously an impact that size would not kill a billion people on the first day, but over the next year or two the climatological, ecological repercussions easily could, depending on where it hits.
Captain Stumpy
5 / 5 (2) Jan 01, 2014
-And that's almost everybody in the entire US haha
Jeez what if it hit yellowstone ??!?!! OMG


@TheGhostofOtto1923

did we really already pass the billion people mark? I thought we were under 500 million?
GSwift7
not rated yet Jan 02, 2014
I'm not going to argue against you when you propose such incredulous scenarios. There's a big difference between hypothetical situations involving a ton of what-if's and the real world. You know just enough to look up the right things, but not enough to really understand them. I have followed the links you posted, but they aren't relevant to this conversation. You've made the jump from talking about our very first attempt to explore an asteroid to some imaginary time in the future when humans have begun commercial exploitation of asteroids. There's no current financial justification for mining an asteroid, despite the handful of companies that are raising investment money to try it. If the financial math worked out, Boeing, Lockheed, etc. would already be doing it.
GSwift7
not rated yet Jan 02, 2014
I'm talking about climate changes and damage to food supply. I don't know what your problem is, but I've seen estimates


Otto is just an antisocial troll, most of the time.

I was talking about the small size objects that NASA is looking at in regard to the above article. I'm not aware of anyone planning to actually move a substantially large asteroid into an orbit in the vicinity of Earth on purpose.

A natural asteroid impact is an entirely different subject.

I would like to point out that a Meteor Crater sized natural impact probably isn't as bad as you're imagining (global disruption?). I've seen the high end estimates that make it onto most television shows, but we have real world examples of similarly sized explosions, such as Mount Saint Hellens. That ash cloud fell onto the US grain belt in the mid-west, and it was a mess, but hardly a global disaster. As an interesting side note, I actually have two glass vials of Mount Saint Hellen ash that I scooped up in Indiana.