It is not possible today, sorry. You need to review your basic studies of materials, for starters. Start with Galileo's discussion in "Two New Sciences" about what happens as you increase the sizes of things. You also need to review your celestial mechanics and your ion drive specs. It would take more than a few decades to move a decent-sized asteroid to Venus. We do NOT have the robots that can do this kind of machining. We do not have the biotech to do what you blindly assume your miracle organisms can do (do you know how little of the Earth's CO2 is in biological sinks? Venus lacks other sinks, so you're looking at vastly exceeding Earth's biosphere in mass alone by factors of, I believe, 10's). Antimatter? Don't be absurd. We're nowhere CLOSE to thinking about handling the stuff in any quantity, let alone using it. NASA funds a handful of projects that they don't expecto to bear fruit, but are interesting on the off-chance that they might (they also fund faster-than-light research, for instance).
Give it up. Venus is no where near within reach for terraforming right now. Why not be happy with exploring it?
1. Really big sheets of metal? No, we can't make that now. We're decades or centuries from being able to move an asteroid into place, refining it and being able to shape it.
2. Try to get permission to use them, even on Venus.
3. We can poke around genetically, but we have very little control. You're proposing totally reworking an organism on a scale that's totally beyond what we can reasonably envision today.
4. True. We also have chemical rockets. Neither will be enough to move an asteroid from 3 AU to 0.7 AU with anything like a reasonable cost.
5. Where are you finding this "nuclear drive"? In as much as treaties ban nukes in space, I have to say that this surprises me.
Your problem is that your assumptions are science fiction. Grounded loosely in today's science, yes. But so is Star Trek. Your blithe complete optimism is the same as what we see in Zubrin and the Mars society: the idea that technology and science will advance as quickly as they would like for their pet project, and exactly along the lines that they would like. As I've said, it isn't necessarily so. You fail to grasp the scale and the difficulty of this undertaking, calling up technology you optimismically think ought to exist in 100 years.
If we ever get to where we can terraform Venus, so be it. I encourage you to write science fiction stories based on the concept of how you'd do it. But right now, any such predictions are silly.
But with all the miracle technology you are positing to do all of this, you might as well assume that we can develop artifical gravity for the Moon (Mars has about half the graviational acceleration of Earth, which isn't bad). For that matter, give your maxim of "if mankind wants it, it shall be so," we might as well figure we'll figure out a faster than light drive and we won't need to muck with Venus given that there are likely other planets well within their habitable zones. Unfortuantely, predictions for technology have a habit of not panning out. I'm still waiting for my hover car, it being 2001 and all.
How are you going to keep the Sun-blocker between the Sun and Venus? It will want to orbit Venus. If you park , it'll only block sunlight over part of the surface, leading to cold regions and warm regions on the day side, not comfortable temperatures. Also, how are you going to keep it together? Between sheer and tidal stresses and constant bombardment, it'll need to be tough.
A couple other points: you lock up the CO2. How do you replenish it? Earth's carbon cycle operates nicely because of our plate tectonics. Venus's total lack of water in the rocks stops plate tectonics. And don't forget that a Venusian day is 244 Earth days. That'll wreck havoc with any caridian rhythms, not to mention making daytime really hot and nighttime very cold.
Surely you can imagine insanely advanced technology to terraform Venus, but it's centuries or more off. As much as I think Mars is really tough to terraform, it's much easier than Venus. The Moon would actually probably be easier.
Whoa, there. Sure, Venus has not more CO2 overall than Earth does. But Venus is almost completely lacking in water. Not in the air, on the ground or in the rocks (to such a degree that the rocks behave differently than Earth's). You'll need to import a planets' worth of water to Venus if you ever want to terraform it. And you have to keep that water around while you're trying to remove the CO2 from the atmosphere, which will be quite tricky. (The water tends to evaporate, travel high into the atmosphere, dissociate and the hydrogen escapes.)
To make matters worse, Venus is still too close to the Sun to be habitable without artifical tending of the climate (something I don't know how to do, do you?). Venus was probably too close 4 billion years ago, and the Sun has only gotten brighter since then.
Finally, how are you going to get the plants down there so that they can survive long enough to make a shred of difference? Venus surface is at 700+K. Roll that around for a moment. Remember, Earth's hottest is around 300 K. No organic tisses can survive at that temperature, not even the hyperthermophiles found near subsurface vents (that no organisms get close enough to the vents to feel this kind of heat indicates that there is a serious problem here). Bioligists estimate that at above 420 K or so, live simply cannot exist. After all, Vega I and II didn't last more than an hour each when they landed on Venus, and they were metallic constructs, not tissue.
Oxygen isn't the factor, methinks, it's the tenuousness of the gas. For astronomers, one particle per cubic centimeter is high for elements like sulfur. Even the Io plasma torus, dense by astrophysical standards, is only around 1000 per cubic centimeter in sulfur. If you mixed this gas in with normal, sea-level air, that would be around one part in 1016. There just isn't enough there to trigger the olfactory receptors strongly enough to be detected.
The Moon, however, is only 1/81 the mass of the Earth due to its lower density. The center of mass of the system is within the Earth's surface and much, much closer to Earth than to halfway between. Also, if you accept the standard formation model, the Moon is more easily thought of as a moon of Earth and not a planet unto itself. Ditto Charon, incidently.
Jupiter and Saturn aren't brown dwarfs, they are too small for that. And if you believe that they do have cores (the data indicates this, but the error bars are large), then they didn't form like stars and brown dwarfs, but rather like planets.
Actually, incorrect. The center of the mass in the Earth/Moon system is about 7/10 of the way from the Earth's center to its surface, but not outside. I just punched the numbers through.
The martian is asymmetry is refered to as a north/south one. The craters are externally created, but your conclusion that that implies the asymmetry is externally driven is false. Internal processes wipe out craters. A more geologically active northern hemisphere will result in fewer craters in that hemisphere. Supporting this is the point that the age of the southern highlands is around 4 billion years old, making them as old as the Moon's surface. So the southern hemisphere has simply not been resurfaced, unlike the north.
You might want to note that most of the impact cratering on any body occurred in the first billion years of the solar system's existence. So I don't see how losing the water billions of years ago has much affect on the asymmetries.
Now, if you can explain why the near side of the moon should have gotten hit by impacts less than the far side, do tell. I've heard a few explanations, but they all break down on closer examination. If the asymmetry is in fact interally generated, the Moon would then be twisted around to align one face towards the other due higher order gravitational torquing. So it ise that this explaination makes the most sense to many of us.
You're right, the focus of the articles is off. The discovery of a large KBO is interesting, the classification of Pluto less so. But that's the media for you.
On the other hand, you completely miss my point. When we discover these KBOs there are instantly recognized as such. I know of no disagreement on this point. That fact that the KBOs are starting to look more and more like Pluto leads to the increasing feeling that we've found Pluto's true family.
If you can find me an asteroid the size of Earth that is oblong, I'll be worried. Basic physics and geology predict a body that large would be made sphereical by self-gravity. Earth's classification would be a minor triffle compared to suddenly not understanding gravity and the physics of rock. If you could, by some miracle, find a body that is of Earth-size and is clearly asteroidal in nature (composition, etc) but also look like a whole lot like the Earth (asteroids don't), we'd have a problem. This is the case with Pluto: compostion and orbit both look more and more like the bodies we classify as KBOs the more of the KBOs we find.
Pluto has always been outside the classifications of the major planets: it isn't like the terrestrial planets and it isn't like the Jovian. In a sense, our mistake was finding it too soon. If it had waiting until now to be found, we'd have put it in the KBO family without a thought.
Is the, as you harp on, semantics? Yes. But that doesn't make it moot. As I've said several times in this discussion, what we call things affects how we think about them. Pluto might not care, but people who think about Pluto will. So the issues should be waved away completely.
Defining "planet" isn't done for Pluto's sake. It's done for human beings' sakes. A good classification scheme in greatly helpful in trying to understand things in science. Where we put Pluto affects how easy it is to see the patterns. Pluto doesn't give a fig, of course, but I do. And my students do, as well, when it comes time to study for the test (in as much as a good classification makes it easier to understand and study).
Because the definition affects how we think about things. That's the point of such classifications: to make thinking about things easier. As we learn more, we discover that our old classifications were naive and sometimes misleading. Remember stars "OBAFGKM"? Did you ever wonder why they are in that order? Because originally they were ABCD..., but that scheme turned out to obscure what was really at work, so it was modified.
Unfortunately, in astronomy, information trickles in. We can't go and disect a planet or watch it form to figure out how to best classify it.
What amazes me is that the general public get's so huffy and indignent at the idea that these classifications might require adjusting. They accept that voting boundries, definitions of "adult" and speed limits change, but not that how we classify Pluto. Weird.
It does shed light on Pluto. The problem with calling Pluto a minor planet and a Kuiper Belt Object is that it is significantly larger than the KBOs known today. But as we continue to fill out the distribution of KBOs, approching Pluto's size, we are left with Pluto starting to fall IN this distribution, rather than appearing to be an outlier. The key here is that the KBOs that we are discovering are undisputably KBOs. A new body found to be half the size of Earth would probably be instantly recognized as a major planet, which would do nothing to affect Earth's classification.
The ratioes (aka, the Titus-Bode Law) break down, actually, around Uranus. It's an interesting rule, but probably more a result of small number statistics.
Mars has hemispherical asymmetries like Earth's Moon does. Mars's are North/South, unlike the Moon. Planetary scientists are shying away from any explanation involving asteroids peppering the planets only during certains times of day. I saw a wonderful talk by a geophysicist here a year ago where he presented work that indicates that these asymmetries are probably the result in asymmetries in how fluids flow inside the bodies early on. It was quite compelling work,
You are correct that tensile strenght (chemical bonding forces) become important in comet/asteroid sized bodies. But gravity is still the key player. Recall that many asteroids and comets are thought to be little more than debris piles losely held together. Chemical forces can't hold these together, since the rocks that make them up aren't bonded to each other. Gravity, however, can do the job.
Tensile strength becomes important when you consider tidal forces. A body that is has some tensile strength will be harder to distrupt tidally than a loose rubble pile. (Note that Roche radii are usual considered for gravitially only bonded objects, tensile strength is neglected.)
Triton orbits Neptune, not Saturn. Saturn has Titan.
Pluto has a thin atmosphere, yes. So does Io. And Mercury has only as much as Earth's Moon (basically nil). Does this affect the use of atmosphere as part of the criterion?
You should become a professional astronomer. For making more sense than those who are involved in the planet vs planetoid dispute (which I think
is silly.) It's classification, not science!
I'm a bit miffed that people think that planetary scientists spend out days sitting around arguing about this, firing off papers and rebuttals to journals and so forth. We don't. There is definately a debate on this issue, but it tends to crop up over drinks or lunch, sort like where people start arguing about which football team will win the Superbowl. It's not something we're really that worried about, and I think we all realize that in due time it will be settled.
Does this point matter? Actually, a little for two reasons. First, funding. If Pluto is downgraded in status to minor planet, odds are that what money for Pluto studies and a Pluto mission there is will decrease even further. Planets are sexier in budget allocations on the Hill. The second reason is pedagougical. When I teach my students about the different types of bodies in the Solar System, Pluto is by far best categorized with the Edgeworth-Kuiper Belt objects. Trying to classify it as a planet (in the usual sense) leads to questions about how it fits with the terrestrial/Jovian split and, ultimately, confusion.
Reclassifying Pluto won't change a whit of it's orbit, it's mass, or anything about it. But it will affect how we humans think about Pluto. That is, after all, what classifications are for. Putting in the best spot isn't vital, but it is helpful.
I do wish that the idea that Pluto is an escaped moon of Neptune would die out. Dynamically, it's neigh impossible to get a moon away from a planet (intact is tougher still) and have it not get reaccreted by the planet. Remember, the orbits must still cross and over a few million years, the smaller body will end up striking the larger!
Even if you do get Pluto away from Neptune, you have to migrate it's orbit out many AU to it's current location. As of last I looked (last May, for a talk I gave on the Pluto/Charon formation and dynamical evolution), no one knows how you could reasonably do this.
It is much easier and more reasonable to assume Pluto accreted out of the protoplanetary disk like the other KBOs. Many of them have high eccentricities. Pluto, being in the 3:2 resonance with Neptune, has even more reason to be in such an orbit if you accept the hypothesis that Neptune has migrated outward through the Solar System by about 5 AU. Dynamical studies indicate that Pluto's eccentricity would get pumped up as it moves out with Neptune (being locked into their resonance).
Hoyle didn't create the idea of the big bang at all. The idea was first put forward shortly after Einstein published his theory of general relativity. Hoyle would have been at most 5 years old. Hubble's discovery that the universe is expanding in the 1920's (Hoyle would have been 10) give the idea a large, swift kick forward.
According to Eric Chaisson's Hubble Wars (Chaisson is the author of a popular introductory astronomy text and was the first director of educational outreach of StSci), yes, a simple test performed by amateur mirror grinders WOULD have revealed the flaw. What's worse is that the manufactor knew of the flaw. There exist holograms of the mirror that show an interference pattern indicating the problem.
In this case, incompetence is probably the answer. As I recall, they ran their budget something like 6 times over thier bid, and still recieved a bonus for a job well-done. All in all, these guys were awful. Happily, they are no longer in business (Raytheon bought them out, I believe).
I think that the rationale is that we could use the money being expended now to help launch a newer, better telescope. Hubble has flaws and it is dated technology (it is mostly 1970's era). I'm not saying I, personally, agree that this means that it is time to end HST, but it's an argument to be considered in this.
That's exactly the story I recall from Eric Chaisson's "Hubble Wars." It's a rather good book, if you're into what goes on behind the scenes. Basically, the story was that the deviced the tested the shape of the mirror was broken. They wedged a roll of tape inside the machine to "fix" it, but not surprisingly, this didn't result in the accuracy required (1/10 of a wavelength on the surface).
Slashdot Mirror
Give it up. Venus is no where near within reach for terraforming right now. Why not be happy with exploring it?
2. Try to get permission to use them, even on Venus.
3. We can poke around genetically, but we have very little control. You're proposing totally reworking an organism on a scale that's totally beyond what we can reasonably envision today.
4. True. We also have chemical rockets. Neither will be enough to move an asteroid from 3 AU to 0.7 AU with anything like a reasonable cost.
5. Where are you finding this "nuclear drive"? In as much as treaties ban nukes in space, I have to say that this surprises me.
Your problem is that your assumptions are science fiction. Grounded loosely in today's science, yes. But so is Star Trek. Your blithe complete optimism is the same as what we see in Zubrin and the Mars society: the idea that technology and science will advance as quickly as they would like for their pet project, and exactly along the lines that they would like. As I've said, it isn't necessarily so. You fail to grasp the scale and the difficulty of this undertaking, calling up technology you optimismically think ought to exist in 100 years.
If we ever get to where we can terraform Venus, so be it. I encourage you to write science fiction stories based on the concept of how you'd do it. But right now, any such predictions are silly.
But with all the miracle technology you are positing to do all of this, you might as well assume that we can develop artifical gravity for the Moon (Mars has about half the graviational acceleration of Earth, which isn't bad). For that matter, give your maxim of "if mankind wants it, it shall be so," we might as well figure we'll figure out a faster than light drive and we won't need to muck with Venus given that there are likely other planets well within their habitable zones. Unfortuantely, predictions for technology have a habit of not panning out. I'm still waiting for my hover car, it being 2001 and all.
A couple other points: you lock up the CO2. How do you replenish it? Earth's carbon cycle operates nicely because of our plate tectonics. Venus's total lack of water in the rocks stops plate tectonics. And don't forget that a Venusian day is 244 Earth days. That'll wreck havoc with any caridian rhythms, not to mention making daytime really hot and nighttime very cold.
Surely you can imagine insanely advanced technology to terraform Venus, but it's centuries or more off. As much as I think Mars is really tough to terraform, it's much easier than Venus. The Moon would actually probably be easier.
To make matters worse, Venus is still too close to the Sun to be habitable without artifical tending of the climate (something I don't know how to do, do you?). Venus was probably too close 4 billion years ago, and the Sun has only gotten brighter since then.
Finally, how are you going to get the plants down there so that they can survive long enough to make a shred of difference? Venus surface is at 700+K. Roll that around for a moment. Remember, Earth's hottest is around 300 K. No organic tisses can survive at that temperature, not even the hyperthermophiles found near subsurface vents (that no organisms get close enough to the vents to feel this kind of heat indicates that there is a serious problem here). Bioligists estimate that at above 420 K or so, live simply cannot exist. After all, Vega I and II didn't last more than an hour each when they landed on Venus, and they were metallic constructs, not tissue.
Oxygen isn't the factor, methinks, it's the tenuousness of the gas. For astronomers, one particle per cubic centimeter is high for elements like sulfur. Even the Io plasma torus, dense by astrophysical standards, is only around 1000 per cubic centimeter in sulfur. If you mixed this gas in with normal, sea-level air, that would be around one part in 1016. There just isn't enough there to trigger the olfactory receptors strongly enough to be detected.
The Moon, however, is only 1/81 the mass of the Earth due to its lower density. The center of mass of the system is within the Earth's surface and much, much closer to Earth than to halfway between. Also, if you accept the standard formation model, the Moon is more easily thought of as a moon of Earth and not a planet unto itself. Ditto Charon, incidently.
Jupiter and Saturn aren't brown dwarfs, they are too small for that. And if you believe that they do have cores (the data indicates this, but the error bars are large), then they didn't form like stars and brown dwarfs, but rather like planets.
Actually, incorrect. The center of the mass in the Earth/Moon system is about 7/10 of the way from the Earth's center to its surface, but not outside. I just punched the numbers through.
You might want to note that most of the impact cratering on any body occurred in the first billion years of the solar system's existence. So I don't see how losing the water billions of years ago has much affect on the asymmetries.
Now, if you can explain why the near side of the moon should have gotten hit by impacts less than the far side, do tell. I've heard a few explanations, but they all break down on closer examination. If the asymmetry is in fact interally generated, the Moon would then be twisted around to align one face towards the other due higher order gravitational torquing. So it ise that this explaination makes the most sense to many of us.
On the other hand, you completely miss my point. When we discover these KBOs there are instantly recognized as such. I know of no disagreement on this point. That fact that the KBOs are starting to look more and more like Pluto leads to the increasing feeling that we've found Pluto's true family.
If you can find me an asteroid the size of Earth that is oblong, I'll be worried. Basic physics and geology predict a body that large would be made sphereical by self-gravity. Earth's classification would be a minor triffle compared to suddenly not understanding gravity and the physics of rock. If you could, by some miracle, find a body that is of Earth-size and is clearly asteroidal in nature (composition, etc) but also look like a whole lot like the Earth (asteroids don't), we'd have a problem. This is the case with Pluto: compostion and orbit both look more and more like the bodies we classify as KBOs the more of the KBOs we find.
Pluto has always been outside the classifications of the major planets: it isn't like the terrestrial planets and it isn't like the Jovian. In a sense, our mistake was finding it too soon. If it had waiting until now to be found, we'd have put it in the KBO family without a thought.
Is the, as you harp on, semantics? Yes. But that doesn't make it moot. As I've said several times in this discussion, what we call things affects how we think about them. Pluto might not care, but people who think about Pluto will. So the issues should be waved away completely.
Defining "planet" isn't done for Pluto's sake. It's done for human beings' sakes. A good classification scheme in greatly helpful in trying to understand things in science. Where we put Pluto affects how easy it is to see the patterns. Pluto doesn't give a fig, of course, but I do. And my students do, as well, when it comes time to study for the test (in as much as a good classification makes it easier to understand and study).
Unfortunately, in astronomy, information trickles in. We can't go and disect a planet or watch it form to figure out how to best classify it.
What amazes me is that the general public get's so huffy and indignent at the idea that these classifications might require adjusting. They accept that voting boundries, definitions of "adult" and speed limits change, but not that how we classify Pluto. Weird.
It does shed light on Pluto. The problem with calling Pluto a minor planet and a Kuiper Belt Object is that it is significantly larger than the KBOs known today. But as we continue to fill out the distribution of KBOs, approching Pluto's size, we are left with Pluto starting to fall IN this distribution, rather than appearing to be an outlier. The key here is that the KBOs that we are discovering are undisputably KBOs. A new body found to be half the size of Earth would probably be instantly recognized as a major planet, which would do nothing to affect Earth's classification.
Mars has hemispherical asymmetries like Earth's Moon does. Mars's are North/South, unlike the Moon. Planetary scientists are shying away from any explanation involving asteroids peppering the planets only during certains times of day. I saw a wonderful talk by a geophysicist here a year ago where he presented work that indicates that these asymmetries are probably the result in asymmetries in how fluids flow inside the bodies early on. It was quite compelling work,
Tensile strength becomes important when you consider tidal forces. A body that is has some tensile strength will be harder to distrupt tidally than a loose rubble pile. (Note that Roche radii are usual considered for gravitially only bonded objects, tensile strength is neglected.)
Pluto has a thin atmosphere, yes. So does Io. And Mercury has only as much as Earth's Moon (basically nil). Does this affect the use of atmosphere as part of the criterion?
is silly.) It's classification, not science!
I'm a bit miffed that people think that planetary scientists spend out days sitting around arguing about this, firing off papers and rebuttals to journals and so forth. We don't. There is definately a debate on this issue, but it tends to crop up over drinks or lunch, sort like where people start arguing about which football team will win the Superbowl. It's not something we're really that worried about, and I think we all realize that in due time it will be settled.
Does this point matter? Actually, a little for two reasons. First, funding. If Pluto is downgraded in status to minor planet, odds are that what money for Pluto studies and a Pluto mission there is will decrease even further. Planets are sexier in budget allocations on the Hill. The second reason is pedagougical. When I teach my students about the different types of bodies in the Solar System, Pluto is by far best categorized with the Edgeworth-Kuiper Belt objects. Trying to classify it as a planet (in the usual sense) leads to questions about how it fits with the terrestrial/Jovian split and, ultimately, confusion.
Reclassifying Pluto won't change a whit of it's orbit, it's mass, or anything about it. But it will affect how we humans think about Pluto. That is, after all, what classifications are for. Putting in the best spot isn't vital, but it is helpful.
Even if you do get Pluto away from Neptune, you have to migrate it's orbit out many AU to it's current location. As of last I looked (last May, for a talk I gave on the Pluto/Charon formation and dynamical evolution), no one knows how you could reasonably do this.
It is much easier and more reasonable to assume Pluto accreted out of the protoplanetary disk like the other KBOs. Many of them have high eccentricities. Pluto, being in the 3:2 resonance with Neptune, has even more reason to be in such an orbit if you accept the hypothesis that Neptune has migrated outward through the Solar System by about 5 AU. Dynamical studies indicate that Pluto's eccentricity would get pumped up as it moves out with Neptune (being locked into their resonance).
Hoyle didn't create the idea of the big bang at all. The idea was first put forward shortly after Einstein published his theory of general relativity. Hoyle would have been at most 5 years old. Hubble's discovery that the universe is expanding in the 1920's (Hoyle would have been 10) give the idea a large, swift kick forward.
According to Eric Chaisson's Hubble Wars (Chaisson is the author of a popular introductory astronomy text and was the first director of educational outreach of StSci), yes, a simple test performed by amateur mirror grinders WOULD have revealed the flaw. What's worse is that the manufactor knew of the flaw. There exist holograms of the mirror that show an interference pattern indicating the problem.
In this case, incompetence is probably the answer. As I recall, they ran their budget something like 6 times over thier bid, and still recieved a bonus for a job well-done. All in all, these guys were awful. Happily, they are no longer in business (Raytheon bought them out, I believe).
I think that the rationale is that we could use the money being expended now to help launch a newer, better telescope. Hubble has flaws and it is dated technology (it is mostly 1970's era). I'm not saying I, personally, agree that this means that it is time to end HST, but it's an argument to be considered in this.
That's exactly the story I recall from Eric Chaisson's "Hubble Wars." It's a rather good book, if you're into what goes on behind the scenes. Basically, the story was that the deviced the tested the shape of the mirror was broken. They wedged a roll of tape inside the machine to "fix" it, but not surprisingly, this didn't result in the accuracy required (1/10 of a wavelength on the surface).