Television is no substitute for a newspaper, at least not if the newpapers were doing their jobs correctly. TV news simply doesn't get you the depth that you get in a newspaper. Part of that is due to the nature of the medium and part of it is because the people producing news programs are more interested in flash than in content. (Yes, I know it's because that's what sells. Consumers are generally dumb and the TV folks are happy to go that route rather to trying to be decent journalists.)
The internet is a good substitute, provided you are smart enough to read reputable sources. (In other words, the same basic people as the ones who print newspapers, only putting the text online instead.) But that doesn't seem to be the draw away from the printed papers. Also, I (and many others) would much rather read a physical piece of paper than a computer screen. I work at a computer 9+ hours a day, typically, but I hate reading significant stretches of text off that screen. I prefer something solid. I can't really articulate why, but I just can't manage the computer screen well.
First, we don't know that all eight planets have cores. The biggest of the lot, Jupiter, is currently an unknown. A new mission is in the works to test precisely this issue, though.
Second, some asteroids DO have cores. And we're pretty certain that many more used to because that's where the metal-rich asteroids came from. (Break-up of larger asteroids which had differentiated.)
Now, I'm not sure what you mean when you say that the "composition is mixed", but I can't seem to make that statement mean anything that's true of the planet's that's not true of Pluto. Pluto has a mixed composition or rock/metal and ices. It also most likely has a core. (Actually, as of last I checked, we're not really sure about the Moon, either. Which really says something.)
The reason that size makes a popular criterion isn't so much that it's easy as that it's feisible. If you require a core as the test, then you pretty much require a spacecraft flyby (or even an orbiter). Which is tricky for a lot of bodies in our solar system and impossible for ones outside of it. As I said, we don't even know if Jupiter has a core, yet.
There is a rumor, which comes from a reliable source, that the IAU stands a good chance of reversing the Pluto decision now. So stay tuned, we might win this yet:-)
It is actually pretty important. Quaoar's mass doesn't tell us that much, overall. The relative masses of Pluto and Charon are keen to constraining models of Charon's formation, something we're pretty keen on doing. I believe that the error on the mass of Charon is around 5-10%, actually. But I'd have to look that up to be sure since it's been years since I've let it keep me awake at night.
"Having multiple moons isn't as important, but does raise some interesting questions;"
Actually, that isn't true. Particularly in the case of Pluto. Multiple moons certainly help refine mass measurements in the general case. In the case of Pluto, Charon is so large (compared with the parent) that you don't GET the mass of Pluto from an orbital period/distance measurement, you get the mass of combined system. (Technically, this is always true. But for most bodies, including all of the planets, the mass of the moon is negledgible.)
Having a couple small moons which are a lot less massive than Pluto should let astronomers finally work out the correct relative masses of Pluto and Charon. Believe it or not, this is not known all that well.
Thank you for that wonderful post. If this debate is to ever be resolved in the minds of the most of the public, we need more practicing Christians to stand up and tell the public that they can be both Christians and scientists. I'm afraid we atheists can talk, but our voices don't carry a lot of weight in many respects. Right now, we're facing the old problem that the extremists (Biblical literalists, in this case) have the loudest voices and so are generally as being the majority opinion for their group (Christians).
Yes, but they didn't design and build the thing themselves, they're effectively just technicians on the project. (Before you take offense, let me note that CU-Boulder builds a lot of instruments, too, and I had friends who worked on some of them. They're getting really good experience, but they're not responsible for the entire project.)
There are other cases of student-designed/built/operated spacecraft, though: SNOE (Student Nitrous-Oxide Explorer) comes to mind. But NASA is *not* going to risk a Mars mission on students, though. It's too expensive.
Wow, I've never heard anyone claim that any of those, apart from Tang, were by-products of the space program. Sounds to me like someone build a straw-man. Note that others have posted links to actual products that resulted from the space program.
Except for that fact that resolution of images of the Earth taken from orbit isn't generally set by the telescope. It's set by the atmosphere between the telescope and the surface, which causes jitter. (The same scintillation that drives telescopes into orbit... or, recently, gets them adaptive optics.) Also, it depends on the wavelength. Hubble can have great resolution in the ultraviolet, but that's not very useful (in general) for observing the Earth since the UV light doesn't make it to the surface (or back again) much of the time.
Somehow, my recollection was that HST's best resolution was nearer 0.1 arcseconds, but that probably pre-dates some of the newer instruments, even if it was ever accurate.
There would be no impact, as such. The Moon's mass doesn't enter into the calculations of the orbit. (Or, rather, it enters and then cancels out of the equations.)
And I would still like to stress that you've over-estimating our ability to mine anything. Even if we had mined the entire crust of the Earth, we'd still have touched less than 0.5% of Earth's volume. (And even less of the mass.)
There are plenty of things to worry about, but this isn't one of them:-)
I didn't say that we did remove Earth's materials from the planet's mass. I thought about making that extremely explicit, but I figured it would be clear. My point is, the mass of the material that we've mined is an insignifcant fraction of the Earth's total mass.
And I'm not jumping to a conclusion at all. I'm basing it on the facts. The Moon is big. You clearly have no grasp of just how big it is, since you're worried about this. In all of human history, we haven't mined more than a tiny fraction of a Moon-mass worth of material here on Earth. And we have a lot more to mine here. There is no prospect on the horizon of us developping technology to use as much mass as the Moon has availible, especially if you consider that the Moon is almost entirely silicate rocks. (Not useful for a whole lot.)
Also, you might want to check out what fraction of Earth's mass is in fossil fuels. Hell, take the entire biomass of the Earth while you're at it. It adds up to much, much less than a percent of the Earth's total mass.
Seriously, check out the numbers. Then you'll see why this is a non-issue.
You realize that there's no way humans can mine a significant fraction of the Moon's mass, right? We haven't even made a dent in our planet in terms of what we've mined, and there are a lot more ores and valuable minerals here to be extracted.
Pretty much, yes. It's even more akin to how mineral deposits and surface compositions are determined from orbiting satellites here on Earth or on other solid bodies. (Jovian moons, for example.)
I'll assume that the first paragraph was a dead-panned joke.
Actually, the analogy would be better if you reversed the roles of the sheep and rabbits. The Moon is quite poor in most of the things that would be useful to us, like ores. (Most of the metals that ought to have been in the Moon ended up in the Earth due to the way the Moon (probably) formed.) So asteroids are far juicier targets for mining, but they're harder to get to. Particuarly if you are thinking of having a Moon base anyway. (Unfortunately, the only way ANY of these resources make economic sense is for off-planet uses. So saying we need a base on the Moon or on an asteroid to mine the materials is circular without other justifications for being there.)
Since the only real economic value for lunar minerals and ores involves their use for the Moon-base (returning them to Earth is more expensive than mining them here), setting up a Moon-base to defend said minerals is a circular argument regardless of the value of the minerals.
The same Norm Coleman who lost the gubenatorial race (along with DFLer Skip Humphrey) to Jesse "The Body" Ventura. Yep.
Warning! Land of Opinions Ahead! Take the following with the appropriate dose of salt! Being from Minnesota originally, I've paid some attention to this guy. My view: he's an utter ass. But worse than that, he's a White House shill in the Senate. (Note: I might disagree with many Republican senators, but I can respect them if they come to their own conclusions and do their jobs. As far as I've seen, Coleman seems to merely do and think whatever Karl Rove tells him to.)
What do you mean by "anti-value"? Love of money seems to me to be a value. It may not be something YOU find a good value to have (and I'd agree with you,incidentally), but I'm pretty sure it's a value.
"Hundreds of years ago the most read books were written by scientists like Newton."
Got data for that? Because I'm pretty sure that hundreds of years ago, the most read books were The Bible and classical literature like The Illiad and The Odyssey. As far as I've ever noticed in history, science has never been popular reading.
Oh, I'm not even violent about the agreement. I was just clarifying. Although I'm not sure if we want to make the assumption that there is as much O_2 in the exoplanet atmospheres as we have on Earth. I'm sure if they find the O_2 bands, the astronomers will be thrilled. But they'll start by looking for ozone for the reasons I've mentioned.
Yes, molecular oxygen does leave a mark in the solar spectrum as measured on Earth's surface, in fact. But that's because there is a LOT of oxygen lying between us and space. In lower concentrations, it becomes pretty dicey. Ozone, however, gives a nice, strong absorption and gives away the presence of O_2. So it has always been considered a preferable way to seeking out atmospheric oxygen.
Detection biomarkers like methane is pretty easy if you can isolate the light from the planet and can get a decent number of photons. (Either through a large collection area or long integrations.) You just look for the distinctive spectral bands for the molecules like methane or ozone. (Oxygen, alas, leaves little mark in the spectrum since it's a homonuclear diatomic molecule and light tends to ignore it.)
Imaging the surfaces will be tougher. You'll need a damn wide apeture (long integration don't help and the resolving power goes linearly with apeture). Remember, we've only imaged a few stars so far, and most of those are larger (in angular size) than these planets. Crud, look at Cassini: we're only getting good images of moons in our own solar system now because we have a spacecraft flying close to them.
Actually, CU is oddly mixed about this. For common parlance, "CU" is the preferred term. But there are a plot of places where "UC" is used internally. Campus boxes are "UCB" (University of Colorado Box"), for example. Or the University of Colorado Health Sciences Center (UCHSC).
Speaking as an alumnus, it's very tough to remember which order you use in a given situation. Although I can think of more annoying things about CU.
Slashdot Mirror
Depth and medium.
Television is no substitute for a newspaper, at least not if the newpapers were doing their jobs correctly. TV news simply doesn't get you the depth that you get in a newspaper. Part of that is due to the nature of the medium and part of it is because the people producing news programs are more interested in flash than in content. (Yes, I know it's because that's what sells. Consumers are generally dumb and the TV folks are happy to go that route rather to trying to be decent journalists.)
The internet is a good substitute, provided you are smart enough to read reputable sources. (In other words, the same basic people as the ones who print newspapers, only putting the text online instead.) But that doesn't seem to be the draw away from the printed papers. Also, I (and many others) would much rather read a physical piece of paper than a computer screen. I work at a computer 9+ hours a day, typically, but I hate reading significant stretches of text off that screen. I prefer something solid. I can't really articulate why, but I just can't manage the computer screen well.
Oops, a lot of this is based on faulty data.
:-)
First, we don't know that all eight planets have cores. The biggest of the lot, Jupiter, is currently an unknown. A new mission is in the works to test precisely this issue, though.
Second, some asteroids DO have cores. And we're pretty certain that many more used to because that's where the metal-rich asteroids came from. (Break-up of larger asteroids which had differentiated.)
Now, I'm not sure what you mean when you say that the "composition is mixed", but I can't seem to make that statement mean anything that's true of the planet's that's not true of Pluto. Pluto has a mixed composition or rock/metal and ices. It also most likely has a core. (Actually, as of last I checked, we're not really sure about the Moon, either. Which really says something.)
The reason that size makes a popular criterion isn't so much that it's easy as that it's feisible. If you require a core as the test, then you pretty much require a spacecraft flyby (or even an orbiter). Which is tricky for a lot of bodies in our solar system and impossible for ones outside of it. As I said, we don't even know if Jupiter has a core, yet.
There is a rumor, which comes from a reliable source, that the IAU stands a good chance of reversing the Pluto decision now. So stay tuned, we might win this yet
It is actually pretty important. Quaoar's mass doesn't tell us that much, overall. The relative masses of Pluto and Charon are keen to constraining models of Charon's formation, something we're pretty keen on doing.
I believe that the error on the mass of Charon is around 5-10%, actually. But I'd have to look that up to be sure since it's been years since I've let it keep me awake at night.
"Having multiple moons isn't as important, but does raise some interesting questions;"
Actually, that isn't true. Particularly in the case of Pluto. Multiple moons certainly help refine mass measurements in the general case. In the case of Pluto, Charon is so large (compared with the parent) that you don't GET the mass of Pluto from an orbital period/distance measurement, you get the mass of combined system. (Technically, this is always true. But for most bodies, including all of the planets, the mass of the moon is negledgible.)
Having a couple small moons which are a lot less massive than Pluto should let astronomers finally work out the correct relative masses of Pluto and Charon. Believe it or not, this is not known all that well.
Thank you for that wonderful post. If this debate is to ever be resolved in the minds of the most of the public, we need more practicing Christians to stand up and tell the public that they can be both Christians and scientists. I'm afraid we atheists can talk, but our voices don't carry a lot of weight in many respects. Right now, we're facing the old problem that the extremists (Biblical literalists, in this case) have the loudest voices and so are generally as being the majority opinion for their group (Christians).
Yes, but they didn't design and build the thing themselves, they're effectively just technicians on the project. (Before you take offense, let me note that CU-Boulder builds a lot of instruments, too, and I had friends who worked on some of them. They're getting really good experience, but they're not responsible for the entire project.)
There are other cases of student-designed/built/operated spacecraft, though: SNOE (Student Nitrous-Oxide Explorer) comes to mind. But NASA is *not* going to risk a Mars mission on students, though. It's too expensive.
Wow, I've never heard anyone claim that any of those, apart from Tang, were by-products of the space program.
Sounds to me like someone build a straw-man. Note that others have posted links to actual products that resulted from the space program.
That's amusing. Terrible pity it just isn't true, isn't it?p
http://www.snopes.com/business/genius/spacepen.as
Except for that fact that resolution of images of the Earth taken from orbit isn't generally set by the telescope. It's set by the atmosphere between the telescope and the surface, which causes jitter. (The same scintillation that drives telescopes into orbit... or, recently, gets them adaptive optics.) Also, it depends on the wavelength. Hubble can have great resolution in the ultraviolet, but that's not very useful (in general) for observing the Earth since the UV light doesn't make it to the surface (or back again) much of the time.
Somehow, my recollection was that HST's best resolution was nearer 0.1 arcseconds, but that probably pre-dates some of the newer instruments, even if it was ever accurate.
There would be no impact, as such. The Moon's mass doesn't enter into the calculations of the orbit. (Or, rather, it enters and then cancels out of the equations.)
:-)
And I would still like to stress that you've over-estimating our ability to mine anything. Even if we had mined the entire crust of the Earth, we'd still have touched less than 0.5% of Earth's volume. (And even less of the mass.)
There are plenty of things to worry about, but this isn't one of them
I didn't say that we did remove Earth's materials from the planet's mass. I thought about making that extremely explicit, but I figured it would be clear. My point is, the mass of the material that we've mined is an insignifcant fraction of the Earth's total mass.
And I'm not jumping to a conclusion at all. I'm basing it on the facts. The Moon is big. You clearly have no grasp of just how big it is, since you're worried about this. In all of human history, we haven't mined more than a tiny fraction of a Moon-mass worth of material here on Earth. And we have a lot more to mine here. There is no prospect on the horizon of us developping technology to use as much mass as the Moon has availible, especially if you consider that the Moon is almost entirely silicate rocks. (Not useful for a whole lot.)
Also, you might want to check out what fraction of Earth's mass is in fossil fuels. Hell, take the entire biomass of the Earth while you're at it. It adds up to much, much less than a percent of the Earth's total mass.
Seriously, check out the numbers. Then you'll see why this is a non-issue.
You realize that there's no way humans can mine a significant fraction of the Moon's mass, right? We haven't even made a dent in our planet in terms of what we've mined, and there are a lot more ores and valuable minerals here to be extracted.
You just need to be more eggzacting in your standards.
Sorry, I'll stop. I promise.
Pretty much, yes. It's even more akin to how mineral deposits and surface compositions are determined from orbiting satellites here on Earth or on other solid bodies. (Jovian moons, for example.)
I'll assume that the first paragraph was a dead-panned joke.
Actually, the analogy would be better if you reversed the roles of the sheep and rabbits. The Moon is quite poor in most of the things that would be useful to us, like ores. (Most of the metals that ought to have been in the Moon ended up in the Earth due to the way the Moon (probably) formed.) So asteroids are far juicier targets for mining, but they're harder to get to. Particuarly if you are thinking of having a Moon base anyway. (Unfortunately, the only way ANY of these resources make economic sense is for off-planet uses. So saying we need a base on the Moon or on an asteroid to mine the materials is circular without other justifications for being there.)
Since the only real economic value for lunar minerals and ores involves their use for the Moon-base (returning them to Earth is more expensive than mining them here), setting up a Moon-base to defend said minerals is a circular argument regardless of the value of the minerals.
You recall incorrectly. Wellstone was up about 6 points on Coleman when the former died.
The same Norm Coleman who lost the gubenatorial race (along with DFLer Skip Humphrey) to Jesse "The Body" Ventura. Yep.
Warning! Land of Opinions Ahead! Take the following with the appropriate dose of salt!
Being from Minnesota originally, I've paid some attention to this guy. My view: he's an utter ass. But worse than that, he's a White House shill in the Senate. (Note: I might disagree with many Republican senators, but I can respect them if they come to their own conclusions and do their jobs. As far as I've seen, Coleman seems to merely do and think whatever Karl Rove tells him to.)
So it's just what you judge to be bad?
That doesn't sound like a useful term in a scinetific context if it's up to each person to judge which is which.
What do you mean by "anti-value"?
Love of money seems to me to be a value. It may not be something YOU find a good value to have (and I'd agree with you,incidentally), but I'm pretty sure it's a value.
"Hundreds of years ago the most read books were written by scientists like Newton."
Got data for that? Because I'm pretty sure that hundreds of years ago, the most read books were The Bible and classical literature like The Illiad and The Odyssey. As far as I've ever noticed in history, science has never been popular reading.
Oh, I'm not even violent about the agreement. I was just clarifying. Although I'm not sure if we want to make the assumption that there is as much O_2 in the exoplanet atmospheres as we have on Earth. I'm sure if they find the O_2 bands, the astronomers will be thrilled. But they'll start by looking for ozone for the reasons I've mentioned.
Yes, molecular oxygen does leave a mark in the solar spectrum as measured on Earth's surface, in fact. But that's because there is a LOT of oxygen lying between us and space. In lower concentrations, it becomes pretty dicey. Ozone, however, gives a nice, strong absorption and gives away the presence of O_2. So it has always been considered a preferable way to seeking out atmospheric oxygen.
Detection biomarkers like methane is pretty easy if you can isolate the light from the planet and can get a decent number of photons. (Either through a large collection area or long integrations.) You just look for the distinctive spectral bands for the molecules like methane or ozone. (Oxygen, alas, leaves little mark in the spectrum since it's a homonuclear diatomic molecule and light tends to ignore it.)
Imaging the surfaces will be tougher. You'll need a damn wide apeture (long integration don't help and the resolving power goes linearly with apeture). Remember, we've only imaged a few stars so far, and most of those are larger (in angular size) than these planets. Crud, look at Cassini: we're only getting good images of moons in our own solar system now because we have a spacecraft flying close to them.
Actually, CU is oddly mixed about this. For common parlance, "CU" is the preferred term. But there are a plot of places where "UC" is used internally. Campus boxes are "UCB" (University of Colorado Box"), for example. Or the University of Colorado Health Sciences Center (UCHSC).
Speaking as an alumnus, it's very tough to remember which order you use in a given situation. Although I can think of more annoying things about CU.