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NASA Making Plans To Save the Earth
aluminumangel writes, "Taking a page out of a Michael Bay movie, NASA is considering a manned mission to land on an asteroid, 'poke one with a stick,' and see how feasible it would be to deflect it from its course. Obviously, the application would be valuable in a doomsday situation and hopefully could keep us from going wherever the dinosaurs went." The article makes oblique reference to another goal such a mission could serve: giving us something to do in space, something to engage the paying public, between the time we return to the Moon and the time we get to Mars.
If this means finally launching Ben Affleck into space, I'm all for it.
They really need to hurry, Bruce Willis isn't getting any younger!
If we can good at altering asteroid's paths, we could use near earth asteroids as ramming tools. We should ram a few into the same spot on Mars and get a nice deep crater. We get practice diverting asteroids and learn more about deeper martain soil.
Demented But Determined.
I'm a fan of space and staying busy till the end times come, don't get me wrong, but what can poking a comet tell us that we wouldn't be able to figure out using the known laws of physics and, you know, science and stuff....
There are some who take responsibility for the world that they live in and others who just hope that everything will work out. Good on those in column a, for those in column b just do everyone a favour and don't get in the way. BTW I think it is worth mentioning that we are likely to kill each other long before an asteroid wipes us out but hey, better safe than sorry right?
...from the original
As an exercise for my high-school physics students studying energy and momentum conservation, I had them run the numbers on the scenario from the movie "Armageddon" for an asteroid "the size of Texas", taking this to mean in separate cases the area of Texas with a range of densities, etc.
Giving the astronauts every benefit of the doubt (able to intercept it twice as far out as they did in the movie, bomb able to be placed at the center of mass, the bomb having ten times the yield of largest nuke ever exploded by man, perfectly elastic explosion, etc. etc. etc.) they not only couldn't make the asteroid miss the Earth, they would only have changed impact points by about a meter!
I love sci-fi movies and like to give my students problems from popular films that illustrate the absurdity of Hollywood stories.
If you can divert it, you can steer it. If you can steer it you can target an area on the planet.
Take out a major city, no radiation. Just the threat would be a useful tool of terror and control.
putting the 'B' in LGBTQ+
If ever a story deserved an "itsatrap" tag, this story is one of them. Who can say what the result would be? It could have unintended consequences.
I hope they pick a small asteroid to test on.
phew, I feel safer knowing that Michael Bay's movies are the blueprint for saving the world. At least I can rest easy tonight.
FromTFA:
Actually the apollo stack (SM, CM, LM ascent and descent stages) had easily enough velocity budget to fly to and return from some near Earth asteroids. It didn't have the consumables to do it but that could have been launched separately. You get more redundancy that way.
Of course we don't have the apollo CM, which is the only spacecraft in existance which could make a high speed return from an asteroid and reenter the atmosphere, but we will have the CRV which should have similar capabilities. The saturn 5 launch system doesn't exist either and thats the part of this system which is really vapourware.
Anyway good luck to them. Mars has been held off for so long because it is so much more risky and difficult than the moon. Asteroids offer progressively harder challenges, minus the risk of sudden death landing a heavy vehicle on mars.
http://michaelsmith.id.au
except, without people, you wouldn't get to have tearjerker bravery/sacrifice with "don't want to miss a thing" playing in the background.
Now all we need is an asteroid for them to save us from.
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Humans are infinitely re-programmable.
Technically, the dinosaurs didn't go anywhere. They just shrunk and grew feathers.. we know grow them in factory farms and eat them by the pound at Chik-Fil-A.
(That and worship our them as our yellow masters through PBS.)
-GiH
Leaving aside the horrible acting in Armaggedon, the portrayal of reality in that movie is atrocious! There are different levels of science fiction, requiring differing levels of suspended disbelief. It runs the gamut from Star Wars, where things like hyperdrive and lightsabers are somehow possible, to Star Trek, some of which could be possible in the 24th century, to 2001, which definitely could have taken place in 2001. This movie seems to exist somewhere inbetween - it wants to come off as being possible today, and yet requires a complete disposal of all scientific knowledge.
In college I took a course on science and communication - how we try, and often fail, to explain science and technology to the public. One homework assignment was to watch the movie Armaggedeon and describe the ways they get it wrong. The "it" here includes:
* physics (it actually takes days to go from earth to the moon - even then it took the Saturn V rocket to get the relatively small Apollo LM/CSM craft that far. Oh, and the old favorite, that there's lots of things to hear in space.),
* propulsion technology (the notion that a space station has a propulsion system capable of generating 1 g of continuous acceleration, or that the shuttle's engines can produce several g's of acceleration all on their own),
* engineering (that you could build a space station that wouldn't collapse under 1 g of acceleration),
* medicine (that space dementia is a likely condition, resulting in careless manslaughter behavior),
* probability (that out of the total surface of the earth, the only places that get struck are NYC, Paris, and Hong Kong (?)),
* astronomy (that, up close, asteroids seem to be made of very brittle stalagmites of rock, and spew radioactive-looking gas).
Science in general. This was a film seen by millions of people - it is probably the first thing most people think about when the subject of asteroids comes up. It's well for Carl Sagan that he was already deceased - the notion that such a movie existed would have killed him. Armaggedon's contemporary, Deep Impact, was more plausible and realistic, if you can get past Elija Wood being a teenager. Alas, it tanked.
I gave up after filling 10 pages with the first hour of the movie - it was too painful to continue.
Hey you will go screwing up all those astrologists and their predictions if you start moving crap around! Think of the ASTROLOGISTS!!!!!
I for one welcome the uprising against the new asteroid overlords.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
"And in other news a freak accident has sent an asteroid involved in a mock doomsday mission hurdling towards Earth. How will this affect your weekend? Stay tuned for Tom and his weekend weather forecast."
Deflecting something from a particular course is likley a lot easier than setting it on to a specific new course. All you need is a big enough push (or bigger) to ensure it missing hitting (for example) Earth. Now to have it hit a particular target, you would need much more exact placing and timing of an explosion/rocket/etc.
My crude reverse-engineering of the asteroid suggests that it would have to have been moving very very slowly compared to the Earth, and be about 50 miles across. Even so, the calculator predicted that anything within the horizon of such an impact would be instantly vaporized and that the entire hemisphere would be subject to earth tremors of magnitude 11.2 or above. That was about the smallest-scale devastation I could find that would produce the right-sized crater.
(Faster asteroids would be smaller, for the same-sized crater, but end up releasing much more energy, as energy goes up with the square of the velocity.)
Now, turning an asteroid (or comet) is plausible, but it has to be done early. You say you can only achieve a meter or so, but in reality that doesn't mean anything. You change the trajectory, and the change of displacement is then the distance the asteroid travels divided by the tangent of the angle between the original path and the new path. (The tangent is equal to the opposite over the adjacent - SOH CAH TOA. You make the adjacent the line it would originally have followed and the opposite becomes the displacement.) Objects travelling along a curved trajectory need to be mapped into a linear system first, which is usually a very simple transform.
So how does this help? Well, since you are changing an angle, the implication is that if you increase the distance away you make this change, you will increase the displacement from the original position. If the change in displacement exceeds the Earth's radius plus the safety margin needed to prevent the Earth's gravity from causing the collision to occur anyway, then it makes bugger all difference if you can make one degree of change or one billionth of a second of a degree. All that matters is that the cumulative change places the body outside the danger zone.
What does this mean in practice? In practice, it means that if it's just about to collide, there is nothing you can do to stop it and there are few structures in the world capable of withstanding 11.2 magnitude tremors. Evacuating the hemisphere and placing everyone on a geologically-sound plateau would be far cheaper and would have a much better chance of success. Near-zero, as opposed to absolutely zero.
If the body is unlikely to collide for a couple of orbits and a few hundred years, then you can talk about serious landscaping the solar system. That's the kind of distance where even a small angle will make a large difference. Better yet, gravity is vastly more powerful than any explosion - if you can shift the orbit just enough to place the body close to a large planet, the total deflection will vastly exceed anything explosives can achieve. Gravity is a significant force on these scales.
This all assumes that the body is solid, of course. The Japanese robot probe that landed on an asteroid not too long ago found a nearby asteroid whose density was unimaginably low - it is likely to be nothing more than space grit held together with collective gravitational attraction where the packing is no better - and probably worse - than coarse-grain sand. It could be said that its structure is best described as sheer damn luck. You fire off a nuke on something like that and there's no telling what will happen, other than most of the energy will go straight through it. At this point, we simply don't have anything like a large enough catalog of asteroids, nor in anything like sufficient detail, to know if this is a freak accident or the norm. Until you know enough of the basics, you can't know anything about the complexities.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Dude. First, take a deep breath. Then, go here and hit Refresh over and over until the bad feeling goes away. After that, take a walk in the woods, or go to church, or help out at a day-care or something. Life has meaning if you go look for it. :-)
Information wants to be anthropomorphized!
I'm surprised that no one has mentioned the obvious: Using an asteroid landing as a precusror to a mining mission.
If NASA's plans go forward, they're going to need a space infrastructure. Eventually, that will mean space-based manufacturing. For manufacturing, you need raw materials. Those raw materials are expensive to lift from Earth's gravity well. Ergo, the best solution is to mine them from much smaller gravity wells where the cost of transport is comparitively minimal.
The key issue that an mission to an asteroid would need to resolve is the actual composition and concentration of valuable ores. Scientists currently have a lot of educated guesses, but we won't know for sure until a geologist makes a proper survey.
Yeah, right. And heavier-than-air flying machines won't work, and if they did, they'd be much too expensive and dangerous for anyone.
You're dead on when considering the current state and economics of technology -- going to the Moon may be (and going Mars is certainly) too expensive for a sustained effort. Right now. However, with the parallel progress in any number of fields, such as materials science, computer aided design and simulation, energy related technologies (let's get some really efficient nukes into space!), what was impossible 80 years ago became possible as stunts for major governments 50 years ago, commercial propositions 25 years ago, and the playground of billionaires and even mere dirt-poor multi-millionaires today. If we were to dump our technical know-how back in time onto the Victorians, they still wouldn't have been able to afford building and operating commercial airplanes -- they just weren't rich enough for the infrastructure. That took a number of decades to roll out.
However, while I think you're wrong in specifics, I agree that automated solutions (despite all the shortcomings of IT) will be cost effective much sooner than all the infrastructure necessary to support huge protoplasmic bags of water and impurities such as yours truly. But nature abhors a vacuum (and we kinda like it!) -- where it's possible to go, someone will, eventually, if only through Brownian motion!