Talk:Asteroid impact avoidance

Charon disambig?

Could someone more familiar with this subject matter take a look at this sentence?

For comets in the range of the then estimated 100 km diameter, [[Charon]] served as the potential example.

Can we confirm that this should be pointing to Charon (moon), or to something else?

Thanks KConWiki (talk) 14:10, 21 February 2015 (UTC)

Perhaps they were referring to comet/centaur 2060 Chiron? Charon is 1200 km and bound to Pluto. -- Kheider (talk) 15:13, 21 February 2015 (UTC)

I take it none of you actually went to the bother of just reading the reference that is attached? https://e-reports-ext.llnl.gov/pdf/232015.pdf Planetary defense workshop LLNL 1995. Pg 258 and indeed pages before and after it clearly state it as ChAron. All this speculation that they were talking about ChIron is post-hoc without any contextual understanding of what was known about ChAron at the time of publication, moreover it is completely devoid of all adherence to the rules on WP:OR for you editors to have inserted ChIron on the grounds of your own personal speculation.

I have since reverted your post-hoc reasoning. Desist in adding speculation without first corroborating it with references.

Perhaps you could research and then write up the evolution of understanding about the nature and size of ChAron, specifically focusing on measurements prior to the year 1995, as a form of redemption, and report your findings in its article page.

178.167.254.173 (talk) 03:53, 12 April 2015 (UTC)

There has never been a 'Charon type comet' as mentioned in the referenced article; there are Chiron type comets. The article has a typo. Here is a 1989 reference mentioning Pluto's moon Charon: https://books.google.com/books?id=DN-v0fQSfPkC&pg=PA869&dq=charon+class+comet&hl=en&sa=X&ei=_8gqVdPLLceXNrqegbgM&ved=0CKYEEOgBMFo

Chiron type comets: https://en.wikipedia.org/wiki/2060_Chiron#Cometary_behavior

Bkobres (talk) 20:15, 12 April 2015 (UTC)

The moon Charon was/is considered a KBO/comet. --> http://csep10.phys.utk.edu/OJTA2dev/ojta/course1/comets/overview/oort_tl.html Secondly, you still haven't posted about what the best estimates on the diameter of Charon were in 1995. Were they greater than 100 km in diameter? Or pretty much 100?

The Planetary defense workshop article does not appear to have a typo, as Charon with an A is what is discussed, and this spelling is used multiple times across a large number of disparate pages, yet Chiron with an I is never mentioned at all in the entirety of the document!.

Therefore the only way you could convince me that the article does have some kind of endemic "typo" as you suggest, is, if you track down the best estimates for the diameter of Charon, in or around the year 1993-5, and those estimates are not anywhere close 100 km. Is this not a reasonable level of evidence for you?

31.200.157.49 (talk) 02:44, 28 May 2015 (UTC)

Teller workshop

The Tsar bomb stuff is WP:SYN and I couldn't find the stuff about "instantly vaporizing" asteroids with 1 GT warheads in the LLNL workshop proceedings. That paragraph is getting silly, needs better sources. Geogene (talk) 03:48, 28 May 2015 (UTC)

The "instantly vaporizing" of a 1 km wide body by a 1 gigaton NED(nuclear explosive device) is indeed in the LLNL document. Read it.

178.167.152.146 (talk) 17:11, 17 June 2015 (UTC)

Optimal scenario, a water comet pre-heated to the vaporization temperature: 1 km sphere of ice = 5.2*10^11 L =~ 5.2*10^11 Kg of ice, requiring 2.2*10^6 J/Kg specific heat of vaporization, or 1.1*10^18 J. The energy equivalent of 1 gigaton of TNT is only 4.2*10^18 J. In other words, once you have somehow preheated the comet nucleus to the vaporization point, you still have to transfer the heat from the warhead into the nucleus at at least 25% efficiency, which is not possible. Vaporizing a stoney body with no iron is risible. More importantly, it isn't in the source. And there are other problems as well, including WP:PRIMARY. Geogene (talk) 00:10, 18 June 2015 (UTC)

The repeated use of the word "could" is FUD

Recently, I have had to repeatedly change the wording of the nuclear deflection strategem section to reflect what the sources themselves contain. As other editors, (who I now see here on this talk page, also have a history of personal antipathy towards this section of the article) continually editorialize the section with "coulds" and "maybes".

Furthermore, in their reversions of my edits, back to the original tone of "would" and "according to simulations" etc. They contend that the sources actually say "could" and that "we don't know".

Yet the very sources they're referring to include:How it Would Work: Destroying an Incoming Killer Asteroid With a Nuclear Blast

Which doesn't leave any room for doubt how it 'would work. Not "might" or "could" as they like to prefer, but would work, according to the supercomputer simulations.

It's therefore plain as day that their preferred "could" is editorializing FUD. Boundarylayer (talk) 03:34, 20 August 2015 (UTC)

You're reading certainty into the source that just isn't there, that's editorializing. Why did you restore the link to Operation Fishbowl, which has nothing to do with this article? Geogene (talk) 03:52, 20 August 2015 (UTC)

Here we go. From the Popsci article:

"All this depends obviously on exactly where the intercept is done, how far away from the Earth it is, how much time we have left--and all of these are unknowns until we discover a threatening asteroid," Weaver says. "All of these assumptions are assumptions. What I think I'm bringing to the table for the first time are truly validated simulations of these non-uniform, non-circular compositions that will hopefully give policy makers a better understanding of what their options are."

No need to trust his numbers more than he does. Geogene (talk) 03:58, 20 August 2015 (UTC)

Pinging @Boundarylayer: Continuing to take the source out of context [1], particularly since that only applies to asteroids of a certain size class. Geogene (talk) 04:13, 20 August 2015 (UTC)

(1) Operation Fishbowl has a great-deal of connection with this topic, as its objectives were to detonate nuclear explosive devices in space, and it achieved that. So it serves as somewhat of a precedent, and therefore meets the re-quirements for inclusion within the see also section.

(2) With respect to Popsci & the Cielo computer simulations. I have included numerous times the sentiment that -this would, according to simulations do...xyz. I have done this expressly so as to remove the need for inserting the misleading and weasel-esque "could" & maybe" sentiments, that others have taken it upon themselves to inject into the section, and done so without authoritative sources to back-up this editorializing/altering of the sentiment.

Now if you found reputable sources questioning Weaver's assumptions, only then would I agree to inserting shaky "could" sentiments about what he has found, until then however, it is needlessly misleading. Especially when I don't see the problem with saying this would, according to simulations do...xyz

Boundarylayer (talk) 04:31, 20 August 2015 (UTC)

(1) You haven't addressed that the Cielo simulations represent asteroids of a paticular size range, which you have represented simply as "asteroids".

(2) That Fishbowl detonations were done in "space" and any asteroid mission would be in "space" also is an extremely superficial similarity. This article is about asteroid deflection, nuclear weapons are only of passing interest here.

(3) After I quoted the Popsci reference here, looks like you pulled it and substituted a more primary source instead. (Nevermind, I see it became a new paragraph--placing more weight on the popsci source, but without addressing the points I made above. What are your plans for the article? Geogene (talk) 17:23, 20 August 2015 (UTC) Geogene (talk) 17:32, 20 August 2015 (UTC)

(1)I don't need to address that, as Weaver doesn't either, precisely because what works on the medium scale with say explosive device of medium size, will work on the large scale with a similarly upscaled/tailored explosive being delivered.

(2)While the article is about asteroid avoidance this sub-section is about putting nuclear explosive devices in space, therefore as I've already explained to you. It meets the requirments to be within a see also list.

(3)I'm glad you've ceased making false claims about that source and injecting the "could"s everywhere. Boundarylayer (talk) 05:32, 21 August 2015 (UTC)

The available physics packages will only deliver a yield up to a particular size. Basically what's happening here is that if "asteroid" can cover objects from a few meters up to 20 km in size, then there must exist some category of asteroids sufficiently small that they can be destroyed by a nuclear weapon. Suggesting that we could just design a bigger warhead is not realistic when Weaver and Wie are both focusing on short-notice events. Your effort to extrapolate their work to cover all possible asteroids is misleading, especially when your source for Weaver has Weaver suggesting nukes are a last option. All of this means that "could" is a better term (and your accusations of FUD, which I understand is considered a type of propaganda) are not only absurd, but probably a violation of behavioral guidelines. So if you can't help but put nonsense in the article, please at least refrain from being obnoxious in the process. Geogene (talk) 18:16, 21 August 2015 (UTC)

Some Wie quotes from a source, to illustrate my point

Now, some salient quotes from Wie's NIAC Phase II study to illustrate my argument above: Thus, for the most probable mission scenarios, in which the warning time is shorter than 5 years, the use of high-energy nuclear explosives in space will become inevitable. A scenario in which a small (e.g., 50 to 150 m) Earth-impacting NEO is discovered with short warning time is considered the most probable scenario because smaller NEOs greatly outnumber larger NEOs, and smaller NEOs are more difficult to detect. (page 15) When the warning time is very short, disruption is likely to become the only feasible strategy, especially if all other de­flection approaches were to fail, as was concluded in the 2010 NRC report [10]. However, it is again emphasized that non-nuclear techniques should be preferred for non-destructive deflection of hazardous NEOs whenever we have sufficient mission lead times (>10 years). (page 16) For larger targets: From Fig. 1.8, we notice that a 1-Mt nuclear disruption mission for a 1-km NEO requires an intercept-to-impact time of 200 days if we want to reduce the impact mass to that of the Tunguska event. A 270-m NEO requires an intercept-to-impact time of 20 days for its 300-kt nuclear disruption mission to reduce the impact mass to that of the Tunguska 11 event. Therefore, it can be concluded that under certain conditions, disruption (with large orbital dispersion) is the only feasible strategy providing considerable impact threat mitigation for some representative, worst-case scenarios. [that'll be pretty hard to fly with less than a 5 year warning, won't it?] source: [2] Geogene (talk) 19:13, 21 August 2015 (UTC)

Quotes from a source on Weaver, to illustrate my point

And for Weaver: The simulations suggest that a 1-megaton nuclear blast could deter a killer asteroid the size of Apophis or somewhat larger. (pdf page 2) Weaver will next turn to simulating larger and larger rocks of varying compositions up to the size of a “dinosaur killer” (about 6.2 miles across). (pdf page 4) [Anybody seen those calculations?] “From my perspective,” he says, “the nuclear option is for the surprise asteroid or comet that we haven’t seen before, one that basically comes out of nowhere and gives us just a few months to respond,” says Weaver. [3] So a nuke "could" disperse a small enough asteroid. Not "would", and the article exaggerates the likelihood of success, the knowledge of asteroid composition, and the enthusiasm scientists have for this option [as a desperate last choice] Geogene (talk) 19:29, 21 August 2015 (UTC)

Geogene (talk) 19:36, 21 August 2015 (UTC)

Your suppositions are incorrect. The most glaring of them is your repeated attempts to draw in the fact that nuclear-use would be the emergency option with the entirely unrelated issue of what the Cielo computer results of Weaver state. When to the un-biased eye, it really doesn't matter what humans decide to do, that still doesn't change the fact that the simulations say what WOULD happen in the event of a nuclear interception that is energetically tailored to the size of the asteroid.

Secondly, you're contradicting yourself, on the one hand you've thankfully acknowledged "Weaver will next turn to simulating larger and larger rocks of varying compositions up to the size of a “dinosaur killer”", yet on the other hand you have the unrelated, contentious and un-supported argument that "The available physics packages will only deliver a yield up to a particular size". That's just another red herring. Furthermore, US warheads, like the 9 Mt B53 in storage, has a yield almost an order of magnitude greater than the 1.2 megaton device frequently modeled against the ~300 m Apophis, and it is "available", now that's just in the US. The Russians have a 20 megaton device in storage that was previously on top of their R-36 (missile) from 1976 and 1984. Moreover, much larger yield devices are easy to quickly make. Just ask the Soviet Union in 1961. - Tsar Bomba.

All the sources indicate that nukes are being proposed as an emergency option for short notice issues, if the article fails to get that across, it violates the Neutrality policy. And that's not a contradiction: Weaver and Wie still have to work with what's available off the shelf, and only in papers and simulations are they permitted to choose their asteroid. The potential yield of any specific bomb design is limited by the laws of physics. I'm not interested in what the Russians may or may not have laying around in storage, because the sources don't seem to care, they all use B63s. "Easy to quickly make" is unrealistic and OR, please stop making the article imply that that's the case. Sources are talking about a warning of five years or less, potentially down to a few months, combined with a necessary intercept time of at least 200 days before impact for a 1 km target. You're making the article say: "No problem!". I object to that, because none of the sources even remotely agree with it. Geogene (talk) 22:51, 21 August 2015 (UTC)

Again, I fail to understand your argument, how does the results of a computer simulation on nuclear detonation intercepts, need to be tempered with "could"s? Simply because, to you, what "would" happen solely depends on how humans decide to act?

Moreover your above diatribe is grossly misleading. The detection of any >40 m sized incoming asteroid would always be an emergency, unless we had decades, then it'd be just a smaller emergency depending on its exact size. Furthermore, all the sources indicate that NEDs(nuclear explosive devices) are proposed for dealing with both long-distance large threats AND short notice small threats. The article does get this across, I hope? Secondly. "nukes"/nuclear technology is proposed in every major and therefore credible option. From getting kinetic impactors up to speed, to powering tugboats/gravity tractors for decades on end, so the "only in an emergency" thing is just plain wrong, as even when a tugboat would work, a large chunk of "nukes/nuclear material" would still be used. Chemical and solar power are just not up to muster for all but the smallest of threats. If you've read anything more than a little on these non-detonating approaches you'd know they are also generally "nuke" powered at heart.

In that vein, even if we have decades to deal with a moderate sized asteroid and humanity decides to go with the tug boat/gravity tractor mission option, that would conceivably prevent an earth impact, but only by a close shave, we'd still have an asteroid with an orbit dangerously close to earth, circling round us like a shark. What do you propose to do with that? Sure, if it is useful we could mine it etc, but if it's not, we'd have no other choice but to keep up these gravity tractor missions for even more decades until we're satisfied it is far enough away with little to no chance of ever coming back. That doesn't strike me, nor anyone who has thought about it as a great solution. As the alternative argument that will no doubt be issued is: We could do that, or we could go with the cheaper-faster-better route of giving it a good NED push to begin with. A solution that isn't open to clandestinely moving NEOs/asteroids back onto collision courses with Earth - a real possibilty that is open to all the other options, as they can steer asteroids around.

On Weaver and Wie. They don't "all use" the 1.2 Mt B83, some that I've seen use the 9 Mt B53. Secondly they have to work with what's on their shelf for a number of reasons. While no US report that I know of, examines in-depth the possibilty of using Russian NEDs, with the explanation for that probably foremost being that they have detailed information about the performance of US NEDs, and so naturally producing reports on what US NEDs can do, specifically those intended for the Robust Nuclear Earth Penetrator role is technically and politically their best option. While another factor may be that they probably get a "kick-back" from the gov/military for not saying-->"and we'd rely on the russians if the shit hit the fan!", which would be politically unwise to report. Although in this document, by none other than Weaver himself, on the last or 2nd to last page, Weaver actually does hint at asking the Russians/the international community for making the right choice on which specific NED to use, in an actual real-world asteroid-incoming scenario. HERE

With respect to "No problem!"? Where did I write that? While I am accurately summarizing the various reports, it may appear that I am saying "no problem" as nuclear explosive devices(NEDs) are the most versatile of all the avoidance solutions (which the NASA quote in the article even supports). I actually think it would be a major problem to get the NEDs to the asteroid. As greatest impediment to every option, not least the nuclear deflection option is the lack of sufficiently large rocket vehicles. NASA are slowly getting back to building an outer-space vehicle with the SLS(the block II variant) but really we could do with the Saturn V being brought back into service, even as a museum piece, standing ready for launch in a few weeks.

Although I think the article should indeed include that, but I've yet to come across a good source that really explains this obvious problem, that every deflection technology intrinsically faces.

Lastly, nuclear explosive devices are easy to make. Andrei Sakharov produced a conservative design for the 50-100 Mt tsar bomba and it was made in a couple of months(well before we had legacy codes and supercomputers). You can read his memoirs if you like, it's in that. So it's neither "unrealistic" nor "OR". Boundarylayer (talk) 01:46, 22 August 2015 (UTC)

Here's a calculation of the physical effects from 50m asteroid impact, as viewed from 10 miles away [4]. It's a 7 MT explosion. Not impressive, you simply evacuate the local population 50 miles or so, this is a lot easier than space travel, especially on short notice. The only problem is if some moron tries to nuke it, and alters the landing site just before impact, as happened in a war game that took place at the recent, much-discussed planetary defense conference. Source: [5]. Geogene (talk) 02:39, 22 August 2015 (UTC)

This makes that glib assertion in the article that everyone will be fine, legally, with using a nuke against any old asteroid that might be a threat very questionable. Nuking a big asteroid will look like saving the world, nuking a small one will look like target practice. This article continually fails to make the distinction between little asteroids and threatening ones. Geogene (talk) 02:45, 22 August 2015 (UTC)

Firstly, Those effects of nuclear weapons based calculations-fudged-into-service-for-determining-impact events are not accurate, decent for an approximation, but by no means accurate. Check the Brown quote I added on the Chelyabinsk meteor article, and Tunguska page and how those calculations ignore "momentum" etc.

Secondly, it would be criminally negligent to let an impactor hit earth with the destruction of property, as emergency evacuation/crisis relocation plan of an area and then the destruction of that area is all when and good on paper...as long as it's not going to be your house or country/world, am I right? No one would fault a country attempting to prevent an impending natural disaster, as long as they do the job right and don't put others in danger by doing so.

Thirdly, the "war game" as you call it, relayed within the economist article,(cutting through their own editorializing nonsense on the broken window fallacy they like pushing), actually seems to be making the point that; if humanity is going to conduct a deflection mission, we better make it an international affair and with that, do it right the first time round. That is, not hold back/"be a moron" with puny kinetic impactors that may not work against a target made out of rubble(which transpires in their hypothetical scenario). Instead, have, if not as the initial attempt, but at the very least have as an immediate back-up, the ability to hit the threatening object with a series of stand-off nuclear detonations until sufficient deflection is achieved. That's the take home message I read in that article. Lastly, how exactly would it be seen as not saving someones world, but "target practice" if a small asteroid was deflected? I really don't follow you there.

Whatever successful method that will be used(eventually) will be described as "saving the world/livelihoods" of thousands/millions if the asteroid happened to be heading near your or "their" homes.

Boundarylayer (talk) 23:47, 30 August 2015 (UTC)

Melosh is probably the world's foremost expert in modeling the effects of impact events. If you've got a problem with those numbers, then Wikipedia isn't the place to fix it. Likewise for the rest of the above. Geogene (talk) 17:14, 31 August 2015 (UTC)

Failed Verification: Neutron heating

I need a source to verify the following sentence: These effectiveness figures are considered to be "conservative" by its authors as only the thermal X-ray output of the B83 devices was considered, while neutron heating was neglected for ease of calculation purposes. This source [6] does not support it, it says that the figure is "conservative" because the bomb is good for 1.2 MT, not the 1.0 MT in their analysis (see page 15). There's nothing about it in this source: [7], which only says that they ignored everything but thermal x-rays. They ignored everything else according to Source 1 because the compositions of asteroids is not well known and because the radiative output of the bomb is classified, and they were limited to unclassified material. Read the sources before edit warring over them, and try to use them accurately. Geogene (talk) 21:37, 21 August 2015 (UTC)

@Boundarylayer: Geogene (talk) 21:47, 21 August 2015 (UTC)

Are you joking? even the 1 page reference I added to stop your tendentious tagging, displays the fact that the 2007 NASA study, that you acknowledge "says that they ignored everything but thermal x-rays". Also has, right next to this very sentence that you acknowledge is in there, a graph plainly showing that this NASA study that remember ignored neutron heating, has drastically underestimated nuclear effectiveness when it is shown next to all the other peer-reviewed studies that DO include neutron heating, such as "Dearborn"'s.

So really, there's not much point going much further until you acknowledge this.

Boundarylayer (talk) 22:04, 21 August 2015 (UTC)

While I'm also frustrated with your editing style, you still don't seem to comprehend the issue. Part of the problem is that you're interpreting primary sources, which you ought not be doing. Obviously this will require some form of dispute resolution. Geogene (talk) 22:10, 21 August 2015 (UTC)

Let me post this again: the sentence that needs to be supported is: These effectiveness figures are considered to be "conservative" by its authors as only the thermal X-ray output of the B83 devices was considered, while neutron heating was neglected for ease of calculation purposes. Please continue re-reading until you see the problem. Geogene (talk) 22:12, 21 August 2015 (UTC)

By all means, request for a comment if you wish, however I may be seeing a glimmer of hope in you. Are you saying that now you see the graph? Great! Secondly, there is no "primary source problem" as these papers are all peer-reviewed. Thirdly, I supplied the report that has the authors stating this fact*, then when you tagged it, I supplied the 1 page ref to only re-enforce the fact that, indeed the authors are conservative in their performance estimates as unlike many others before them, they did neglect neutron heating.

• See page 15 here, The analysis depends on only X-ray interaction with the asteroid. Neutron interaction is neglected as it is more difficult to predict spectrum and interaction with the asteroid, and that neutron interaction will occur after X-ray interaction

It's all right there in plain english.

Boundarylayer (talk) 23:51, 21 August 2015 (UTC)

I've raised the question at the No Original Research Noticeboard [8] . Geogene (talk) 01:04, 22 August 2015 (UTC)