Deconvolutions are generally iffy under any but the most ideal of circumstances, in my experience. With the point-spread function being what it is (complicated, that's what), we're not in the best of circumstances, either.
I rather doubt that he'd have a source, or at least, not a source of repute. Ball park figures : Chixulub is about 150km in diameter ; diameter/ depth for complex craters is around 10/ 1 ; so depth of the early crater (once the transitional shuffling is over and done with) was in the order of 15km. Typical depth to Moho on typical continental crust is about 30-35km. (There used to be a geological map server at Cornell.edu, which could generate a map of depth-to-Moho over arbitrary regions of the Earth's surface. It seems to have gone now. [SADNESS] )
Yeah, that's what I was figuring more or less. (My estimate for the lithosphere thickness was "a few tens of km", but I agree with the 10:1 as a planetary scientist.) Seemed close to my best guess, but not clearly through or not-through.
I have this vague recollection of *some* impact being thought to have triggered super-volcanism, but that could be feverish imaginations.
I'm not even going to bother counter-arguing you since you don't actually even think about what anyone here is saying.
You really need to think your arguments through before you respond. They are really good arguments but have to many holes in them.
Mostly the "holes" appear to be that they, like the facts of the case, seem to disagree with your pre-conceived notions.
You clearly have no idea of how impacts or spacecraft missions really operate, yet you're pontificating here and stoutly refusing to actually respond to the counter-arguments. Please stop it, you're turning an otherwise useful discussion into morass of misinformation.
Asteroids are highly irregular bodies and often loosely packed. Applying thrusters to the side of one would be a logistical nightmare since you want to push straight at the center of mass (otherwise you're wasting thrust to spin the asteroid) and because you're not sure you won't just bury the spacecraft as you push into a rubble pile.
There is always that chance that someone who is on the spot maybe able to fix the problem. With robots you don't' have that chance.
Read up on the history of unmanned spaceflight and then get back to us on this point. Practically every mission that NASA has flown has had an unexpected failure. Most have been recovered from the ground by the clever engineers. And not every failure on a manned mission can be recovered: anything that happens too fast or requiring tools that they don't have aboard means that they're lost. There's nothing at all magical about having people on board; they can help recover from failures a bit better than robots can, but they also create a lot more ways for things to go wrong. And in the end, they're far more expensive to launch, even if you ignore safety concerns, since such missions are inherently a lot heavier.
You're arguments for a manned mission just don't hold up.
I fully understand the shotgun effect. The damage would be tremendous but it would be manageable.
No you don't and no it wouldn't be. You didn't even read what I wrote: the K-T event managed to incinerate half the planet with the debris that was thrown up as secondary impactors. That's after a lot of energy was dissipated locally at the impact site. It'd be worse if you put that energy straight into the atmosphere.
I'm thinking dinosaur killer when I say punched through to the mantle because that is what that one did. It rang the planet like a bell. That would very likely kills us as a species.
The Earth rings like a bell after every major earthquake. I'm not even sure that you're right that the Chixulub event punched clear to the mantle; got a source? Even if it did, so what? It might trigger some supervolcanism (I know of no evidence of this with Chixulub), but that's hardly the be-all and end-all of ways that impacts kill you.
If there is a dinosaur killer out there coming at us most likely we are boned but the nuke and blasting it to rubble is still the only option if we can't deflect it.
That argument is fallacious on two grounds: a) that deflection is impossible and b) that blasting is superior to taking the hit from an intact body. The second is probably (based upon numerous studies) not true and the former is dubious as well.
For the record, if you're worried about reliability, robots still beat out humans. We've never sent humans that far before and for the same cost, we could build and send many robots to do the job. Even with a 50% failure rate, it would probably still be cheaper and faster to go with the robots. And robots can be fixed (many have been) and not every human-mission failure can be recovered (see: Columbia and Challenger, for example). The reason that human missions have a better statistical record is not because the people aboard can fix all the problems as much as because we spend WAY more money and time on human mission than robots making more certain that problems don't kill our astronauts. In a pinch situation, that would go out the window anyway.
And don't dismiss the shotgun effect if you don't understand it. That many smaller bodies entering our atmosphere, even if they burn up, would deposit their kinetic energy-turned-thermal into the air leaving Earth under a atmospheric broiler. This effect (with the debris being lofted from the ground rather than directly entering from space) is probably what did a substantial chunk of the damage in other impact events (including the K-T) based on available evidence.
Also, where did you get the idea that a consolidated asteroid would punch through to the mantle? I suppose a *really* big impact might do it, but it'd be unusually huge to make that kind of dent. I'm skeptical that anything that big would notice our nukes (or a gravity tractor) anyway. In that case, we're already boned.
To the best of my knowledge, there are no liquids on Venus's surface and no erosional features consistent with liquids to suggest that they've been there since the last resurfacing.
Methane is a natural and expected part of the moons (and planets) in the outer solar system. You'll note that Uranus and Neptune have large methane contents and even Saturn has a noticeable methane haze in its upper atmosphere.
(You don't see a lot of methane on Earth because we have an oxygen-rich atmosphere and methane has a lifetime in the atmosphere of around a decade.)
No, there just aren't many metals that I can think of that would both melt and be found in any real abundance. Also, I've certainly never heard of any evidence of such things from my Venus-studying colleagues, although I admit that I don't attend their meetings.
Not much. This isn't oil on Titan, it's simpler compounds. And the chemistry that works on Titan almost certainly doesn't work on the Earth outside the lab since the temperatures are extremely different.
The hydrocarbons are pretty simple relative to organically-produced ones. You get the more complicated ones on Titan by photo-chemical reactions in the atmosphere. (UV from the Sun breaks bonds which recombine in new and exciting ways.)
Memory (and, ultimately, from talking to the people who do the measurements of spin-states), but the inner moons I mentioned are part of my research, so I'm especially keen on knowing what they're doing.
All of the medium to large satellites (Mimas, Enceladus, Tethys, Dione, Rhea, and Titan, Hyperion, Iapetus, and Phoebe), except Hyperion, which has a chaotic spin, and I think Phoebe, which is irregular as heck anyway. All the captured, irregular moons cannot be counted on to spin locked to the planet. The inner small moons (Pan, Daphnis, Atlas, Prometheus, Pandora, Janus, and Epimetheus) are tidally locked according to the data.
No, Venus's surface is a desert. It'd be hard to get a river of metal anyway: only a few metals are liquid on its surface and not even the extremely abundant ones like iron.
Very well summarized, except I disagree with "has not been adequately explained up to now." It's true that there were things (and remain things!) that we don't understand, but this result is really more incremental than ground-breaking. It's a very good result and nice work all around, but I think that the press-hype is probably a bit over the top.
If they aren't the ones passing the laws, they aren't legislators to begin with. Therefore, if you need popular voting to pass a law, they aren't legislators by definition. Anything else is just you redefining terms to suit your own inclinations, which is both confusing and gives you no basis to correct others.
And no, the less-funded candidate wins nearly half the time (vis-a-vis, there little effect). It matters with close races, but in general it isn't the deciding factor. If you can't be bothered to even check out the source I pointed you to, please don't try to correct me. It's rude and makes you look bad.
Uh, no. "Democratic republic" does not mean that the populace votes on bills. That would be a pure democracy. "Democratic republic" just means that we vote for our representatives. And also, no, it is not particularly the case the the winning candidate spends more than the loser. (There's an analysis of this in Freakonomics. There is a bit of a bias toward the spendier candidate, but it's not a very major effect.)
As you point out, there's much to worry about in our current system, but it's worth having you facts right before you correct others.
Er, very good observation. Humans, however, were the original subject here. Only lawyers of the species slither. The rest of us will probably be uncomfortable. (Which will make the lawyers even happier just as soon as they figure out whom to sue.)
Hm, Slashdot ate my reply which said pretty much what you just said, except that I added that this means that larger planets are almost always denser in spite of the fact that the terrestrial planets have nearly the same composition. (Shut up, Mercury.) A planet larger than Earth should be somewhat denser, so the assumption I made above isn't exactly true. It is, however, probably good enough.
Not necessarily. You'll also get a denser atmosphere, which should alter the dynamics of flying a bit. Our birds might not be able to make it, but I wouldn't be surprised if bird-analogues couldn't evolve there.
I was just getting ready to post asking how often we are going to see teams announcing "the most Earth-like planet yet," but hopefully that won't happen after all. (It still may; science has gotten to love the press-release a bit too much, I think.)
Yeah, that's an unreasonable density, but you should bear in mind that compression occurs. (Earth's uncompressed density is significantly lower than the actual density, for example.)
That said, you can fairly assume that the density is nearly the same as Earth's. In that case, the surface gravity is only about 70% higher than here. It'd still be tough walking around.
Good hypothesis. Now prove it with data, or it's just you shooting the breeze.
And if you don't see why your second point (way above) shows you should have seen why the first one was a strawman, then you're either an idiot or playing one. Either way, I'm not going to argue further, you're ignorant and passing off your opinions as facts, like most people in this "discussion", which is just sad.
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Deconvolutions are generally iffy under any but the most ideal of circumstances, in my experience. With the point-spread function being what it is (complicated, that's what), we're not in the best of circumstances, either.
I rather doubt that he'd have a source, or at least, not a source of repute. Ball park figures : Chixulub is about 150km in diameter ; diameter/ depth for complex craters is around 10/ 1 ; so depth of the early crater (once the transitional shuffling is over and done with) was in the order of 15km. Typical depth to Moho on typical continental crust is about 30-35km. (There used to be a geological map server at Cornell.edu, which could generate a map of depth-to-Moho over arbitrary regions of the Earth's surface. It seems to have gone now. [SADNESS] )
Yeah, that's what I was figuring more or less. (My estimate for the lithosphere thickness was "a few tens of km", but I agree with the 10:1 as a planetary scientist.) Seemed close to my best guess, but not clearly through or not-through.
I have this vague recollection of *some* impact being thought to have triggered super-volcanism, but that could be feverish imaginations.
I'm not even going to bother counter-arguing you since you don't actually even think about what anyone here is saying.
You really need to think your arguments through before you respond. They are really good arguments but have to many holes in them.
Mostly the "holes" appear to be that they, like the facts of the case, seem to disagree with your pre-conceived notions.
You clearly have no idea of how impacts or spacecraft missions really operate, yet you're pontificating here and stoutly refusing to actually respond to the counter-arguments. Please stop it, you're turning an otherwise useful discussion into morass of misinformation.
Asteroids are highly irregular bodies and often loosely packed. Applying thrusters to the side of one would be a logistical nightmare since you want to push straight at the center of mass (otherwise you're wasting thrust to spin the asteroid) and because you're not sure you won't just bury the spacecraft as you push into a rubble pile.
A gravitational system circumvents those issues.
There is always that chance that someone who is on the spot maybe able to fix the problem. With robots you don't' have that chance.
Read up on the history of unmanned spaceflight and then get back to us on this point. Practically every mission that NASA has flown has had an unexpected failure. Most have been recovered from the ground by the clever engineers. And not every failure on a manned mission can be recovered: anything that happens too fast or requiring tools that they don't have aboard means that they're lost. There's nothing at all magical about having people on board; they can help recover from failures a bit better than robots can, but they also create a lot more ways for things to go wrong. And in the end, they're far more expensive to launch, even if you ignore safety concerns, since such missions are inherently a lot heavier.
You're arguments for a manned mission just don't hold up.
I fully understand the shotgun effect. The damage would be tremendous but it would be manageable.
No you don't and no it wouldn't be. You didn't even read what I wrote: the K-T event managed to incinerate half the planet with the debris that was thrown up as secondary impactors. That's after a lot of energy was dissipated locally at the impact site. It'd be worse if you put that energy straight into the atmosphere.
I'm thinking dinosaur killer when I say punched through to the mantle because that is what that one did. It rang the planet like a bell. That would very likely kills us as a species.
The Earth rings like a bell after every major earthquake. I'm not even sure that you're right that the Chixulub event punched clear to the mantle; got a source? Even if it did, so what? It might trigger some supervolcanism (I know of no evidence of this with Chixulub), but that's hardly the be-all and end-all of ways that impacts kill you.
If there is a dinosaur killer out there coming at us most likely we are boned but the nuke and blasting it to rubble is still the only option if we can't deflect it.
That argument is fallacious on two grounds: a) that deflection is impossible and b) that blasting is superior to taking the hit from an intact body. The second is probably (based upon numerous studies) not true and the former is dubious as well.
For the record, if you're worried about reliability, robots still beat out humans. We've never sent humans that far before and for the same cost, we could build and send many robots to do the job. Even with a 50% failure rate, it would probably still be cheaper and faster to go with the robots. And robots can be fixed (many have been) and not every human-mission failure can be recovered (see: Columbia and Challenger, for example). The reason that human missions have a better statistical record is not because the people aboard can fix all the problems as much as because we spend WAY more money and time on human mission than robots making more certain that problems don't kill our astronauts. In a pinch situation, that would go out the window anyway.
And don't dismiss the shotgun effect if you don't understand it. That many smaller bodies entering our atmosphere, even if they burn up, would deposit their kinetic energy-turned-thermal into the air leaving Earth under a atmospheric broiler. This effect (with the debris being lofted from the ground rather than directly entering from space) is probably what did a substantial chunk of the damage in other impact events (including the K-T) based on available evidence.
Also, where did you get the idea that a consolidated asteroid would punch through to the mantle? I suppose a *really* big impact might do it, but it'd be unusually huge to make that kind of dent. I'm skeptical that anything that big would notice our nukes (or a gravity tractor) anyway. In that case, we're already boned.
Which does not reach the surface,either.
To the best of my knowledge, there are no liquids on Venus's surface and no erosional features consistent with liquids to suggest that they've been there since the last resurfacing.
Methane is a natural and expected part of the moons (and planets) in the outer solar system. You'll note that Uranus and Neptune have large methane contents and even Saturn has a noticeable methane haze in its upper atmosphere.
(You don't see a lot of methane on Earth because we have an oxygen-rich atmosphere and methane has a lifetime in the atmosphere of around a decade.)
No, there just aren't many metals that I can think of that would both melt and be found in any real abundance. Also, I've certainly never heard of any evidence of such things from my Venus-studying colleagues, although I admit that I don't attend their meetings.
Not much. This isn't oil on Titan, it's simpler compounds. And the chemistry that works on Titan almost certainly doesn't work on the Earth outside the lab since the temperatures are extremely different.
The hydrocarbons are pretty simple relative to organically-produced ones. You get the more complicated ones on Titan by photo-chemical reactions in the atmosphere. (UV from the Sun breaks bonds which recombine in new and exciting ways.)
Memory (and, ultimately, from talking to the people who do the measurements of spin-states), but the inner moons I mentioned are part of my research, so I'm especially keen on knowing what they're doing.
All of the medium to large satellites (Mimas, Enceladus, Tethys, Dione, Rhea, and Titan, Hyperion, Iapetus, and Phoebe), except Hyperion, which has a chaotic spin, and I think Phoebe, which is irregular as heck anyway. All the captured, irregular moons cannot be counted on to spin locked to the planet. The inner small moons (Pan, Daphnis, Atlas, Prometheus, Pandora, Janus, and Epimetheus) are tidally locked according to the data.
No, Venus's surface is a desert. It'd be hard to get a river of metal anyway: only a few metals are liquid on its surface and not even the extremely abundant ones like iron.
Very well summarized, except I disagree with "has not been adequately explained up to now." It's true that there were things (and remain things!) that we don't understand, but this result is really more incremental than ground-breaking. It's a very good result and nice work all around, but I think that the press-hype is probably a bit over the top.
This to you is not a source? A book written by the author of the peer-reviewed papers on the topic?
Are you joking? You're acting like a 10-year-old at this point.
If they aren't the ones passing the laws, they aren't legislators to begin with. Therefore, if you need popular voting to pass a law, they aren't legislators by definition. Anything else is just you redefining terms to suit your own inclinations, which is both confusing and gives you no basis to correct others.
And no, the less-funded candidate wins nearly half the time (vis-a-vis, there little effect). It matters with close races, but in general it isn't the deciding factor. If you can't be bothered to even check out the source I pointed you to, please don't try to correct me. It's rude and makes you look bad.
Uh, no. "Democratic republic" does not mean that the populace votes on bills. That would be a pure democracy. "Democratic republic" just means that we vote for our representatives. And also, no, it is not particularly the case the the winning candidate spends more than the loser. (There's an analysis of this in Freakonomics. There is a bit of a bias toward the spendier candidate, but it's not a very major effect.)
As you point out, there's much to worry about in our current system, but it's worth having you facts right before you correct others.
Er, very good observation. Humans, however, were the original subject here. Only lawyers of the species slither. The rest of us will probably be uncomfortable. (Which will make the lawyers even happier just as soon as they figure out whom to sue.)
Hm, Slashdot ate my reply which said pretty much what you just said, except that I added that this means that larger planets are almost always denser in spite of the fact that the terrestrial planets have nearly the same composition. (Shut up, Mercury.) A planet larger than Earth should be somewhat denser, so the assumption I made above isn't exactly true. It is, however, probably good enough.
Gah. "Could evolve there". Geez.
Not necessarily. You'll also get a denser atmosphere, which should alter the dynamics of flying a bit. Our birds might not be able to make it, but I wouldn't be surprised if bird-analogues couldn't evolve there.
I was just getting ready to post asking how often we are going to see teams announcing "the most Earth-like planet yet," but hopefully that won't happen after all. (It still may; science has gotten to love the press-release a bit too much, I think.)
Yeah, that's an unreasonable density, but you should bear in mind that compression occurs. (Earth's uncompressed density is significantly lower than the actual density, for example.)
That said, you can fairly assume that the density is nearly the same as Earth's. In that case, the surface gravity is only about 70% higher than here. It'd still be tough walking around.
Good hypothesis. Now prove it with data, or it's just you shooting the breeze.
And if you don't see why your second point (way above) shows you should have seen why the first one was a strawman, then you're either an idiot or playing one. Either way, I'm not going to argue further, you're ignorant and passing off your opinions as facts, like most people in this "discussion", which is just sad.