Small Asteroid To Buzz Earth

← Back to Stories (view on slashdot.org)

Posted by kdawson on Sunday March 1, 2009 @09:55AM from the just-a-flesh-wound dept.

ddelmonte writes in to tell us about a small near-earth object, discovered just 2 days ago, that is expected to pass within 64,000 km of our planet on March 2, 13:44 UT. NEO 2009 DD45 will be well inside the Moon's orbit and just under twice the altitude of geosynchronous satellites. According to Sky and Telescope, 2009 DD45's closest approach will be over the Pacific west of Tahiti, so observers in Australia, Japan, and perhaps Hawaii will have the best chance of spotting it with, say, an 8-in. telescope. Here's where you can generate an ephemeris of the object for your location. At closest approach NEO 2009 DD45 will be moving half a degree per minute and peaking around magnitude 10.5. It will be brighter than 13th magnitude for only a few hours.

171 comments

Min score:

Reason:

Sort:

First... by Anonymous Coward · 2009-03-01 09:59 · Score: 0, Offtopic

AHHHHH!!!!
Second by Anonymous Coward · 2009-03-01 10:01 · Score: 0, Redundant

AHHHHHHHH!!!
Piggy ride! by Chicken_Kickers · 2009-03-01 10:01 · Score: 5, Interesting

Why can't we send a probe that will land on this asteroid and then piggy ride on it. That way we don't need more fuel to carry it round the solar system. If the asteroid doesn't go where we want, then have a relaunch mechanism for the probe to get off at the most suitable point in the asteroid's orbit.
1. Re:Piggy ride! by Anonymous Coward · 2009-03-01 10:05 · Score: 4, Insightful
  
  You don't save any fuel by being near an asteroid. Putting the probe in the same orbit as the asteroid would have essentially the same fuel cost (actually a little less, because you would not have to overcome the escape velocity of the asteroid).
2. Re:Piggy ride! by evanbd · 2009-03-01 10:06 · Score: 3, Insightful
  
  Having the asteroid there doesn't change anything, really. It costs the same amount of delta-v to put a probe on that orbit whether or not there's an asteroid (at least for tiny rocks like this; it would have to be getting toward small moon size to matter much). You already don't need propellant to carry a probe around the system -- things in space just coast, following an orbit determined by gravity. The hard part is getting it onto the right trajectory, not keeping it there.
3. Re:Piggy ride! by amorsen · 2009-03-01 10:06 · Score: 5, Insightful
  
  Why can't we send a probe that will land on this asteroid and then piggy ride on it.
  "Landing" would either actually be "crashing at a speed measured in km/s" or would require just as much fuel as going in the same orbit without the asteroid, and then what's the point...
  
  --
  Finally! A year of moderation! Ready for 2019?
4. Re:Piggy ride! by malkir · 2009-03-01 10:07 · Score: 0
  
  Uhhhhhhh RTFP "that will land on this asteroid and then piggy ride on it."
5. Re:Piggy ride! by CrimsonAvenger · 2009-03-01 10:13 · Score: 4, Informative
  
  Why can't we send a probe that will land on this asteroid and then piggy ride on it. That way we don't need more fuel to carry it round the solar system. If the asteroid doesn't go where we want, then have a relaunch mechanism for the probe to get off at the most suitable point in the asteroid's orbit.
  If we have the deltaV to land on the rock, then we have the deltaV to match its orbit without bothering to land on it. So why waste time with the landing?
  Or were you thinking that little or no deltaV would be required because the rock was passing close by?
  Well, no, a quick guesstimate based on the limited information in the article has it passing at about 9km/s relative to Earth, at 64000km altitude. Which is rather more than escape speed. About 8500 m/s over Earth escape speed, in fact. We've sent probes out faster than that a few times. The stuff that goes out past Jupiter, for instance. But it's a non-trivial exercise.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
6. Re:Piggy ride! by MichaelSmith · 2009-03-01 10:14 · Score: 1
  
  With a thirty metre object you could almost snare it with a net. Then you would need a shock absorbing tether to match velocities. Given that materials for tethers are improving all the time, and that high tech space drives are not inventing themselves the way they do on star trek, I wonder if this could be a practical way to travel around the inner solar system
  
  --
  http://michaelsmith.id.au
7. Re:Piggy ride! by Anonymous Coward · 2009-03-01 10:16 · Score: 0
  
  Well, when I first saw the comment, I was thinking 'uh, that's not going to work' - because you need to accelerate to the asteroids speed to land on it.
  But then, I was thinking, what we really need is some sort of giant elastic bungee cord!
8. Re:Piggy ride! by zappepcs · 2009-03-01 10:32 · Score: 0
  
  IF you land on it, it will continue to travel without fuel for propulsion for a VERY long time... that could be rather useful
  
  --
  Support NYCountryLawyer RIAA vs People
9. Re:Piggy ride! by MichaelSmith · 2009-03-01 10:36 · Score: 4, Informative
  
  IF you land on it, it will continue to travel without fuel for propulsion for a VERY long time... that could be rather useful
  It you match speeds with it you will continue to travel without fuel for propulsion indefinitely. Being docked to a rock will make no difference. The advantage of having the rock there is that you can mine it for resources and use it as a radiation shield. You could also push transfer momentum to it if you want to change your velocity.
  
  --
  http://michaelsmith.id.au
10. Re:Piggy ride! by meringuoid · 2009-03-01 10:45 · Score: 4, Informative
  
  Why can't we send a probe that will land on this asteroid and then piggy ride on it.
  Physics doesn't work that way.
  You seem to think it's like hopping on the back of an old London bus: grab it as it passes and jump up onto the step. But speeds in space are far greater than that. If you try to catch an asteroid as it passes, words like 'splat' or 'crunch' are appropriate. You need to match the asteroid's velocity very closely in order to land on it without being destroyed - and if you can do that, then you're on the same orbit as the asteroid anyway, and you'll go where it goes whether you land or not. So you don't actually need the asteroid to be there.
  I suppose you might arrange something cunning with a big net and a lot of bungee rope, if you can pull off an incredibly accurate flight plan, but even so it's unlikely that the asteroid is going to be near any other targets of interest in the near future; it's more worth your while to load up the extra fuel needed to fly direct to the planet or moon you want to study.
  
  --
  Real Daleks don't climb stairs - they level the building.
11. Re:Piggy ride! by mustafap · 2009-03-01 11:03 · Score: 1
  
  You need to re-think this one a little bit. What propulsion source do you think the asteriod has that a satellite landing on it doesn't?
  
  --
  Open Source Drum Kit, LPLC deve board - mjhdesigns.com
12. Re:Piggy ride! by MurphyZero · 2009-03-01 11:28 · Score: 4, Informative
  
  If you could match speeds with it, you could go where it goes without need for the asteroid. Since the asteroid has no propulsion of its own, it's not providing any benefits, if you 'match' speeds (actually velocity, speed and direction). The benefit only comes in matching position and letting the asteroid change the velocity of the spacecraft to match. As long as the spacecraft survives that impact, then it can be used to provide a great momentum transfer.
  
  --
  Our founding fathers removed the guys in charge. Be American. Vote incumbents out.
13. Re:Piggy ride! by pcolaman · 2009-03-01 11:52 · Score: 3, Interesting
  
  I vote we shoot it down, just to see if we can do it. That would be more fun, anyways. I nominate myself to push the button.
14. Re:Piggy ride! by MrMista_B · 2009-03-01 12:09 · Score: 2, Insightful
  
  Well...
  Landing a probe on an asteroid passing by at this speed, would be like trying to catch a bullet with your bare hands.
  I'd say the mental imagery is pretty close to accurate, in both cases.
15. Re:Piggy ride! by rhyder128k · 2009-03-01 12:22 · Score: 0
  
  Surely the asteroid has considerable inertia due to its mass? A probe would have to apply thrust to overcome gravity wells that it encounters. The asteroid will be affected by the "drag" of passing close to large bodies but already has considerable ineria.
  Let's say that I sent a ping pong ball, a house brick, and a 20t lump of iron heading away from earth at 5 m/s. I would expect the ping pong ball to slow most quickly, followed by the house brick. In some situations, the lump of iron might be able to escape where the others would not. You'd experience the same effect if you tried to stop a car rolling down hill a ten miles per hour and then compared it to stopping a skate board moving at the same speed. Perhaps I'm missing something?
  In addition, a probe on top of an asteroid benefits from at least some protection from collisions.
  
  --
  Michael Reed, freelance tech writer.
16. Re:Piggy ride! by Meumeu · 2009-03-01 12:42 · Score: 2, Insightful
  
  Surely the asteroid has considerable inertia due to its mass? A probe would have to apply thrust to overcome gravity wells that it encounters. The asteroid will be affected by the "drag" of passing close to large bodies but already has considerable ineria.
  Let's say that I sent a ping pong ball, a house brick, and a 20t lump of iron heading away from earth at 5 m/s. I would expect the ping pong ball to slow most quickly, followed by the house brick. In some situations, the lump of iron might be able to escape where the others would not. You'd experience the same effect if you tried to stop a car rolling down hill a ten miles per hour and then compared it to stopping a skate board moving at the same speed. Perhaps I'm missing something?
  Yes, you're missing the basics of physics... This whole post is pretty much bullshit.
17. Re:Piggy ride! by swillden · 2009-03-01 12:49 · Score: 1
  
  The benefit only comes in matching position and letting the asteroid change the velocity of the spacecraft to match. As long as the spacecraft survives that impact, then it can be used to provide a great momentum transfer.
  Gigantic. Bungee.
  Brilliant, huh?
  
  --
  Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
18. Re:Piggy ride! by LingNoi · 2009-03-01 13:15 · Score: 1
  
  Could be useful for mining out, then you have a massive deathstar spaceship made out of rock.
19. Re:Piggy ride! by meringuoid · 2009-03-01 13:19 · Score: 3, Informative
  
  Let's say that I sent a ping pong ball, a house brick, and a 20t lump of iron heading away from earth at 5 m/s. I would expect the ping pong ball to slow most quickly, followed by the house brick. In some situations, the lump of iron might be able to escape where the others would not. You'd experience the same effect if you tried to stop a car rolling down hill a ten miles per hour and then compared it to stopping a skate board moving at the same speed. Perhaps I'm missing something?
  Yeah. No friction or air resistance in space, that's what you're missing. Oh, and all of physics since Galileo, you're missing that too.
  The brick has less mass than the iron lump, true - and so it has proportionately less inertia. But the gravitational force on the brick is also less than that of the iron lump, by the same proportion. The two cancel out. If they have the same velocity, then if one escapes, so does the other. It's the same principle as how a brick will fall at the same speed as a feather, if dropped in a vacuum.
  Similarly, if a spaceprobe and an asteroid fly away from the Earth at the same velocity, it doesn't matter whether they're attached or separate: both will follow the same path.
  
  --
  Real Daleks don't climb stairs - they level the building.
20. Re:Piggy ride! by radtea · 2009-03-01 13:22 · Score: 2, Interesting
  
  Gigantic. Bungee.
  This is actually not completely insane. Just dumping some guesses at "reasonable" parameters into a dumb-as-rocks bit of Python to simulate the encounter, a bungee with a relaxed length of 1000 km and a spring constant of 10^-3 N/m would do the job with a peak acceleration of about 160 g assuming 50 km/s delta-v. Total acceleration time is about 100 seconds, and the bungee stretches out to about two and a half times its relaxed length.
  If you had a material that would stretch up to 10 times its relaxed length you could keep the peak acceleration down to about 25 g!
  These calculations assume the asteroid is much more massive than the probe--if it is not then the numbers actually get a bit better, as the asteroid slows down a bit as the probe accelerates.
  In any case, I wouldn't rule this out. Hardened instruments can take insanely high accelerations, and materials are getting more incredible all the time.
  
  --
  Blasphemy is a human right. Blasphemophobia kills.
21. Re:Piggy ride! by Anonymous Coward · 2009-03-01 13:22 · Score: 0
  
  Yeah, well done. Why don't we ask Michael Bay if he's interested in contributing to your pathetic attempt at a response. We can even see if Liv Tyler and that face scrotum looking fella to come along for the ride as well.
22. Re:Piggy ride! by Workaphobia · 2009-03-01 13:34 · Score: 1
  
  I think the notion of relative velocities is enough to eliminate that prospect entirely. If you don't match velocities with the object your piggybacking onto, you're crashing into it. If you do match speeds, then what was the point of the piggybacking in the first place?
  
  --
  Evidently, the key to understanding recursion is to begin by understanding recursion. The rest is easy.
23. Re:Piggy ride! by swillden · 2009-03-01 13:55 · Score: 2, Funny
  
  a bungee with a relaxed length of 1000 km and a spring constant of 10^-3 N/m would do the job with a peak acceleration of about 160 g assuming 50 km/s delta-v. Total acceleration time is about 100 seconds, and the bungee stretches out to about two and a half times its relaxed length.
  :-)
  Of course, then there are the issues of getting a 1000 km bungee up there, and figuring out how to lasso the asteroid.
  
  --
  Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
24. Re:Piggy ride! by lpzie · 2009-03-01 15:30 · Score: 0
  
  I'm sensing a Watchmen reference.
25. Re:Piggy ride! by CrimsonAvenger · 2009-03-01 15:39 · Score: 2, Interesting
  
  With a thirty metre object you could almost snare it with a net. Then you would need a shock absorbing tether to match velocities.
  It's a 30 metre object moving well over escape velocity. You snag it with the net, and then endure 9000 gravities acceleration, and in only a tenth of a second, you've matched orbits.
  If your tether will stretch to a length of 450 metres while holding a weight (you, or a satellite your size) of about 2000 tons.
  Good luck with that.
  
  Given that materials for tethers are improving all the time, and that high tech space drives are not inventing themselves the way they do on star trek, I wonder if this could be a practical way to travel around the inner solar system
  In a word, no. If you want more words, "practical" doesn't begin to describe this notion.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
26. Re:Piggy ride! by CrimsonAvenger · 2009-03-01 15:43 · Score: 1
  
  Landing a probe on an asteroid passing by at this speed, would be like trying to catch a bullet with your bare hands.
  Good imagery. Note that the the rock is moving about five times as fast (relative to Earth) as the fastest bullet.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
27. Re:Piggy ride! by apostrophesemicolon · 2009-03-01 15:44 · Score: 1
  
  seeing as matching speed and then land is irrelevant, then the only beneficial way is to shoot the probe onto the asteroid right as it passes.
  I understand that the error margin is very much less, not to mention the risk of damaging the instrument upon impact. But if we're to take advantage of both the momentum of the asteroid and the opportunity to study it, this is the way to go.
28. Re:Piggy ride! by Anonymous Coward · 2009-03-01 15:48 · Score: 0
  
  it will not save fuel. Once the prob is in an orbit, say one that matches the astroid's orbit, it doesn't need any fuel to stay there.......CAS
29. Re:Piggy ride! by CrimsonAvenger · 2009-03-01 15:50 · Score: 3, Informative
  
  Let's say that I sent a ping pong ball, a house brick, and a 20t lump of iron heading away from earth at 5 m/s. I would expect the ping pong ball to slow most quickly, followed by the house brick. In some situations, the lump of iron might be able to escape where the others would not. You'd experience the same effect if you tried to stop a car rolling down hill a ten miles per hour and then compared it to stopping a skate board moving at the same speed. Perhaps I'm missing something?
  Have you read anything by this guy Newton? Fig, or Isaac, one of the two. He pretty much explained (about 300 years ago) how this whole "gravity" thing works.
  And, for what's it's worth, 5 miles/second (I shudder to think you might have meant metres/second) is below escape velocity. It's barely above orbital velocity. So not even your lump of iron would escape. Even if gravity worked they way you think it does, as opposed to the way it really does.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
30. Re:Piggy ride! by retchdog · 2009-03-01 15:54 · Score: 2, Interesting
  
  It's not crazy at all: http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
  Compared to using pneumatic springs to harness and dampen the force of exploding atomic bombs in order to propel a manned craft, coupling to an asteroid is downright quaint.
  
  --
  "They were pure niggers." – Noam Chomsky
31. Re:Piggy ride! by rhyder128k · 2009-03-01 15:59 · Score: 1
  
  OK, OK. Looks like a made mistake on that one. Although, I did phrase my point as a question, as I'm no expert on space science. My mistake.
  
  --
  Michael Reed, freelance tech writer.
32. Re:Piggy ride! by Anonymous Coward · 2009-03-01 16:46 · Score: 0
  
  Thanks for restating exactly what the post you replied to said.
33. Re:Piggy ride! by nacturation · 2009-03-01 16:48 · Score: 1
  
  Solar wind?
  
  --
  Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
34. Re:Piggy ride! by Provocateur · 2009-03-01 17:32 · Score: 1
  
  Well, if you go by his sig, he'll still defend you to death...right? Right? Hello? hmmm, seems like he left...
  
  --
  WARNING: Smartphones have side effects--most of them undocumented.
35. Re:Piggy ride! by MichaelSmith · 2009-03-01 19:38 · Score: 1
  
  With a thirty metre object you could almost snare it with a net. Then you would need a shock absorbing tether to match velocities.
  It's a 30 metre object moving well over escape velocity. You snag it with the net, and then endure 9000 gravities acceleration, and in only a tenth of a second, you've matched orbits.
  So use a long tether.
  
  --
  http://michaelsmith.id.au
36. Re:Piggy ride! by MichaelSmith · 2009-03-01 19:47 · Score: 2, Insightful
  Gigantic. Bungee.
  This is actually not completely insane.
  It is an insanely exciting idea. Imagine hooking on to an object like that in a small spacecraft. A few thoughts on the subject:
  
  Build an unmanned probe with can outfit a small asteroid with docking hardware. It could attach itself with two loops of rugged cable. Attached too the cable would be a socket which tethers can attach themselves to. A single installation could be used for decades by different spacecraft.
  Catch the asteroid with your tether extended. Consider the asteroid moving along +Z at 10km/s. Tether is 1000km long and the spacecraft is 1000km away from the point of capture along +X. Immdiately before capture explosives on the tether end assembly fire to accelerate the end of the tether. Magnetic and electric fields in the tether and socket may assist in a fast capture. Doing it this way eliminates sudden loads as the tether takes up slack. Instead the spacecraft is swung around (yeah at high G) and releases when it is headed in the right direction.
  Equip vehicles with heat shields and solar sails. Both require only present day technology. Aerobraking at (say) Venus could be used for a course change.
  Consider using angular momentum from Asteroids and free space tethers to store energy. One vehicle could sump energy into an object, another could make use of it.
  --
  http://michaelsmith.id.au
37. Re:Piggy ride! by Anonymous Coward · 2009-03-01 20:26 · Score: 0
  
  I think the more important question is why the hell NASA didn't detect this months, even years ago.
  2 days notice for an asteroid?
  We're all dead in the future then. 100% Certain.
  What is all the money for NASA.
  Absolute disgrace.
38. Re:Piggy ride! by Ihmhi · 2009-03-01 21:02 · Score: 1
  
  Has nobody on Slashdot ever heard of harpoons or grappling hooks?
  IANAA (I Am Not An Astrophysicist), but let's say hypothetically that this asteroid is 1 km in diameter. We send up a probe with a 1.1km tether. The probe releases the tether into the path of the asteroid, and the end of the tether has hooks. When the asteroid smacks into the tether, the probe hooks into it.
  At this crucial moment, the probe must begin accelerating to match as much of the speed of the asteroid as possible without overtaking it. Eventually the tether will go taut. The probe then reels it in, plops down on the asteroid, and attaches itself to the thing with struts.
  I've read plenty of "Why attach to an asteroid when we can just match its speed, it's the same thing, blah blah". No. It's not the same thing.
  1) The asteroid acts as a huge shield. It can protect the probe from various things we wouldn't want it to be exposed to.
  2) Yes, we can propel to x speed as the asteroid, but every time we want to change direction fuel must be spent. If the asteroid changes direction ever, that's quite literally a free ride.
  3) Depending on where it lands, we could get some pretty cool pictures. What if it heads towards some planet a few light years away and smacks into it? Imagine the awesome telemetry we could get from the probe.
  
  --
  Random Thoughts From A Diseased Mind (Not For Dummies)
39. Re:Piggy ride! by beowulfcluster · 2009-03-01 21:55 · Score: 1
  
  4) Most importantly, riding an asteroid is just plain fucking cool.
40. Re:Piggy ride! by honkycat · 2009-03-01 23:10 · Score: 1
  
  IAAA, granted not one who studies near-Earth objects or asteroids...
  But, beyond direct exploration of the asteroid itself (and, ok, the kickass-cool factor of riding an asteroid), there really is little purpose to tagging along. Furthermore, it's serious sci-fi to even contemplate doing so. Your tether idea is interesting, but remember the speed difference between the asteroid and your probe is gonna be thousands of MPH so we're not just talking about a climbing rope here... so the path from "interesting" to "plausible" to deployment is a major engineering undertaking!
  The asteroid is unlikely to provide significant shielding in any useful way. It's going to be rotating rapidly, and there's no reason to suspect it'd be on the right side to provide shielding even if it were not spinning. A probe you could even pretend to use for rapid-response activity like this with a straight face is not going to have any capability to move after it's landed, so you can't play some game claiming you'll just move to the "safe" side.
  Furthermore, once you're in the same orbit as the asteroid, you really will follow its path. Unless you think the thing is a self-propelled asteroid, it isn't going to change direction. There's no advantage to actually being on it. I think the reality is, given the cost of even a cheap probe, for the simple matter of getting around the solar system, it's probably not worth it. You'd have to get the cost down to the point where you can afford just throwing away a lot of probes that don't wind up somewhere interesting -- until then, you really need to very carefully choose where your instrument winds up.
41. Re:Piggy ride! by matt4077 · 2009-03-01 23:28 · Score: 1
  
  That wouldn't make much sense. To land on the asteroid, you need to be about as fast as it is, or your lander will just be hit by a very fast moving rock. When you have invested all the energy to get up to that speed, you could equally well just turn of the engines and be subject to gravity, just like the asteroid, which will give you that tour around the solar system without any further energy.
  
  --
  Fleur de Sel
42. Re:Piggy ride! by Bearhouse · 2009-03-02 00:11 · Score: 1
  
  With any luck the probe would modify the asteroid's orbit just enough so that the next time round it slammed into earth.
43. Re:Piggy ride! by drinkypoo · 2009-03-02 01:10 · Score: 1
  
  If your tether will stretch to a length of 450 metres while holding a weight (you, or a satellite your size) of about 2000 tons.
  
  Some spiders catch prey many times their size by creating webs which include stress-release points which consist of a glob of sticky material filled with some gathered web. When a heavy impact hits the web, the gathered material pays out and distributes an immense amount of force.
  By making the tether stretch to 100x its length you could reduce the shock to 90 Gs nominal, which is theoretically doable. heh heh.
  I don't think we'll do it today or tomorrow, but maybe next week, eh?
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
44. Re:Piggy ride! by drinkypoo · 2009-03-02 01:14 · Score: 1, Informative
  
  Yeah. No friction or air resistance in space, that's what you're missing. Oh, and all of physics since Galileo, you're missing that too.
  
  That's not true. There is a very small amount of air resistance in space (interstellar hydrogen.) In theory, stuff released out into space won't coast forever relative to the origin - just damned near it. Also, two items released into "empty" space on a parallel course will NOT continue on a parallel course. They will gravitationally attract one another. Who's missing what, now? :)
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
45. Re:Piggy ride! by FictionPimp · 2009-03-02 01:34 · Score: 1
  
  What if you placed a probe directly in the path of the asteroid, then unfurled a few hundred km long spring. Then the asteroid would compress the spring as it began to impact the probe. One the spring was fully compacted it would redirect the energy into the probe providing a free speed boost.
46. Re:Piggy ride! by Anonymous Coward · 2009-03-02 01:43 · Score: 0
  
  If you could catch up to it, then you are in the same orbit and don't need the asteroid itself to stay in that orbit silly.
47. Re:Piggy ride! by mea37 · 2009-03-02 04:42 · Score: 1
  
  I've never heard of a harpoon or grappling hook that could survive the use you want to put it to. The hook, and/or the tether, and/or the probe, and/or the asteroid itself would be destroyed during the tug-of-war between the asteroid and the probe.
  There's also a very real concern that the attempt to accelerate the probe would drag the asteroid into a much less interesting orbit. Equal and opposite reactions, conservation of momentum, etc. My guess is, if you could make the probe survive the attempt to tether itself to the asteroid, it would subsequently be destroyed when the asteroid carried it into a crash with whatever it had previously been orbitting.
  "Yes, we can propel to x speed as the asteroid, but every time we want to change direction fuel must be spent. If the asteroid changes direction ever, that's quite literally a free ride."
  Since the asteroid has neither fuel to spend nor a means to spend it, it isn't going to change direction.
  Note that "change direction" here means "deviate from a predetermined orbital path"; which is also the only sense in which it is true to say that "changing direction costs fuel".
  "Depending on where it lands, we could get some pretty cool pictures. What if it heads towards some planet a few light years away and smacks into it?"
  The asteroid has the same probability of going someplace interesting as the probe would have on its own.
48. Re:Piggy ride! by Ihmhi · 2009-03-02 05:27 · Score: 1
  
  The asteroid wouldn't change direction under its own power. Such an assumption would be absolutely ludicrous on my part. I was talking more about gravitational forces of things bigger than the asteroid affecting its trajectory.
  
  --
  Random Thoughts From A Diseased Mind (Not For Dummies)
49. Re:Piggy ride! by mea37 · 2009-03-02 05:43 · Score: 1
  
  The point is, any external influence on the asteroid's path (such as a large gravitational pull) would have exactly the same impact on the probe's path, whether the asteroid is present or not. Gravity affects all matter equally.
50. Re:Piggy ride! by Mister+Whirly · 2009-03-02 06:10 · Score: 1
  
  Yes, I can't believe an organization with limited resources can't track an unlimited number of asteroids and their respective trajectories all in real time simultaneously.
  
  And your prediction that we are all dead in the future? Duh. Everyone dies. It doesn't take Nostradamus to predict we aren't all immortal.
  
  Any other nuggets of wisdom you want to spout off now, or is the well pretty much dry??
  
  --
  "But this one goes to 11!"
51. Re:Piggy ride! by ElAurian · 2009-03-02 06:58 · Score: 1
  
  Because it would cost just as much in delta-vee to synch the probe's orbit with the asteroid's orbit and land on it, as to just put the probe in the EXACT SAME orbit without the asteroid being there.
  To save fuel using the asteroid, you'd have to use some sort of springy tether to hook the asteroid and let it accelerate you without fuel. Not an entirely crazy idea, but we don't know how to do it yet.
  Another possible use for the asteroid is physical shielding from the Sun's heat, but we don't know whether this asteroid is going near the Sun or not.
52. Re:Piggy ride! by Hordeking · 2009-03-02 07:12 · Score: 2, Informative
  
  OK, OK. Looks like a made mistake on that one. Although, I did phrase my point as a question, as I'm no expert on space science. My mistake.
  I understood where you were coming from. These are common beginners' misconceptions.
  Here's how it works (you confused a few things). We have things like mass, cross-sectional area (important in slowing things down), density, etc.
  For starters, let's use your ping pong ball, brick, and iron. Furthermore, let's assume a perfect vacuum. If I fire them all at velocity v, they'll continue forever at velocity v. Mass doesn't make them slow down (but it does affect how much energy I have to expend to make them go velocity v).
  Now, let's get a little deeper as to why this is. All objects have mass (pretty much every non-quantum mechanical object in existence), which is a measure of what we call inertia. Inertia is just a fancy word that basically states that an object with mass resists changes to its motion (Newton's eponymous first law). This means point masses tend to travel in straight lines if they were already doing that. Or it could simply be stopped (it won't just spontaneously start moving for no reason). What all this means is that a ton of iron is a hell of a lot harder to stop than a 1/4oz ping pong ball. (Newton's 2nd law: force required to change something is proportional to its mass, i.e. the heavier it is, the more ass you have to put into it to move, the "more mass, more ass" principle) This is where your slowing down question comes in.
  Now, let's assume that our thought-experiment space is actually filled with something like air or water. If you've ever been in a swimming pool, river, or gale, you know that both air and water can definitely slow you down or move you about. This is called "resistance", and it's basically a form of Newton's 3rd law (every action has an equal and opposite reacion). Now, let's assume two objects of equal mass, but one is a really large sheet while the other is compact like a bullet. Moving through the water/air/solar wind/intergalactic hydrogen medium, this stuff exerts force on our objects as they pass through. However, the sheet interacts with a lot more of the medium, since it has a larger cross-sectional area per unit mass, so it slows down more quickly than our compact bullet. This is why a feather floats to the ground slowly, while a rock simply falls. On a more significant scale, at sufficient speeds, lots of heat gets generated by friction. This is pretty good for us, since the atmosphere protects us from debris from space.
  Hopefully that helps you.
  
  --
  Disclaimer: The opinions and actions of the US Gov't are in no way representative of those held by this author or its ci
53. Re:Piggy ride! by Anonymous Coward · 2009-03-02 10:59 · Score: 0
  
  I vote for changing its orbit carefully so that we get an extra moon.
54. Re:Piggy ride! by Anonymous Coward · 2009-03-04 18:33 · Score: 0
  
  Because once you've matched the velocity of the asteroid, there is no energy benefit to a piggy-back ride. The size of the rocket you'd need to match velocity would carry the probe along the same path and orbit, whether it's attached to the asteroid or not. Now if you're talking about landing on it for compositional analysis, or studying it's orbital path, that's a different story, but otherwise, there'd be no energy conservation through a piggy-back ride.
55. Re:Piggy ride! by Anonymous Coward · 2009-03-08 14:26 · Score: 0
  
  Why can't we send a probe that will land on this asteroid and then piggy ride on it. That way we don't need more fuel to carry it round the solar system. If the asteroid doesn't go where we want, then have a relaunch mechanism for the probe to get off at the most suitable point in the asteroid's orbit.
  Didn't read any responses below, but there's no drag in space. If you spent the amount of energy to speed a vessel up in order to land on the rock, you'll no longer need to spend any more energy (fuel) to keep it moving at that speed.
Third by Anonymous Coward · 2009-03-01 10:02 · Score: 0, Redundant

AHHHHHHHHHH!!!!!!
Impossible in this timespan by RabidMoose · 2009-03-01 10:04 · Score: 5, Informative

(IANARS) There's simply no way that any space agency could prepare and launch a probe with less than three days notice, and likely no good way to pre-build one without knowing what size/speed asteroid we might be lucky enough to launch at.
1. Re:Impossible in this timespan by PolygamousRanchKid+ · 2009-03-01 10:24 · Score: 4, Funny
  
  (IANARS) There's simply no way that any space agency could prepare and launch a probe with less than three days notice, and likely no good way to pre-build one without knowing what size/speed asteroid we might be lucky enough to launch at.
  I dunno . . . The Thunderbirds seem to be able to get anywhere they want to go, real fast. And Doctor Who just seems to be able to go where ever he damn well pleases, as well.
  
  --
  Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
2. Re:Impossible in this timespan by Hurricane78 · 2009-03-01 11:06 · Score: 4, Funny
  
  Unfortunately though, they also have the disadvantage of not being real.
  Which is quite unfortunate, in reality.
  
  --
  Any sufficiently advanced intelligence is indistinguishable from stupidity.
3. Re:Impossible in this timespan by Nyeerrmm · 2009-03-01 11:55 · Score: 4, Interesting
  
  While you're absolutely correct, there is a program known as Operationally Responsive Space (ORS) thats being headed up by DoD rather than NASA that is headed in that direction. I think the time-frame they're considering is closer to 2 weeks, but the general idea is to be able to recognize a need, and design, construct and launch a mission in that period of time. That includes getting adjustable plug-and-play parts (GNC, Power, structures, propulsion) that you can tune and modify quickly to fit the mission profile.
  Presumably, a lot of the work to streamline the process of designing the bus and plugging in instruments could be easily translated to space science missions, and if a future opportunity like this were available we could do exactly that. Of course, you'd have to have a pretty interesting guidance system and a very robust structure, since you'd only get an advantage if you stuck the probe in the asteroids path and let it slam into it to get the momentum.
4. Re:Impossible in this timespan by dpilot · 2009-03-01 12:48 · Score: 1
  
  But Dr. Who only gets exactly where he pleases when it satisfies the writers. Most of the time it seems that some sort of space-time vortex sucks him off-course, or the Tardis misbehaves, or other such circumstance landing him in the wrong space/time.
  
  --
  The living have better things to do than to continue hating the dead.
5. Re:Impossible in this timespan by FatdogHaiku · 2009-03-01 12:53 · Score: 1
  
  And Doctor Who just seems to be able to go where ever he damn well pleases, as well.
  Well sure, once you can go anywhen, it makes it a lot easier to go anywhere. Anyplace was everyplace (and very small to boot) at some point in time, so you go backwards in time until it's all close together, relocate, and then go forward in time staying with your new location...
  
  --
  You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
6. Re:Impossible in this timespan by Pharago · 2009-03-01 13:50 · Score: 1
  
  Welcome to the eve-online fitting screen, NASA...what do you want to fly today?
7. Re:Impossible in this timespan by Puffy+Director+Pants · 2009-03-01 13:53 · Score: 5, Funny
  
  Dude, if you can make a functional space craft that looks like an English Police box, I'll support your candidacy for head of Nasa.
8. Re:Impossible in this timespan by ElderKorean · 2009-03-01 19:47 · Score: 1
  
  But Dr. Who only gets exactly where he pleases when it satisfies the writers. Most of the time it seems that some sort of space-time vortex sucks him off-course, or the Tardis misbehaves, or other such circumstance landing him in the wrong space/time.
  Just once they should go somewhere and nothing happens - maybe only a 5min episode to keep us hooked.
  Speaking of near misses.
  Don't forget that many many years ago the Doctor (and Adric) accidently set off life on this planet. Though only one of them lived to tell about it I guess.
9. Re:Impossible in this timespan by Big+Hairy+Ian · 2009-03-01 22:00 · Score: 1
  
  As for the probe itself I agree but the Russian space agency can handle a 2 day turn around for the launch vehicle in just about any weather.
  Please no "In Soviet Russia....." Jokes they stopped being funny years ago!
  
  --
  Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
10. Re:Impossible in this timespan by Kjella · 2009-03-02 01:22 · Score: 1
  
  Without the time machine? Meh. Besides, why do you want to copy the only non-functional technology on the TARDIS? Chameleon circuit, now we're talking...
  
  --
  Live today, because you never know what tomorrow brings
11. Re:Impossible in this timespan by idigitallDotCom · 2009-03-02 01:47 · Score: 2, Interesting
  
  THREE days?????? surely the space agencies had some inkling about this asteroid much longer before now? Surely they do some sort of skywatch/asteroid/meteor monitoring. What's so special about this asteroid that noone knew it was coming around here and how big/fast it is? I'd be seriously worried if 3 days was their minimum time to interception.
  
  --
  blog.idigitall.com
12. Re:Impossible in this timespan by avtchillsboro · 2009-03-02 02:58 · Score: 1
  
  Unfortunately though, they also have the disadvantage of not being real.
  Which is quite unfortunate, in reality.
  reminds me of the Yogi Berra quote:
  
  "In theory, there is no difference between theory and practice. In practice there is."
13. Re:Impossible in this timespan by Dr.M0rph3us · 2009-03-02 03:06 · Score: 4, Informative
  
  From TFA:
  "This little cosmic surprise, designated 2009 DD45, turned up two days ago as a 19th-magnitude blip in images taken by Rob McNaught at Siding Spring Observatory in Australia. It was already within 1.5 million miles of Earth and closing fast."
  So no, they had no prior info about this asteroid. And yes, this fact concerns me as well, but this is the problem with asteroids / comets having a low albedo - they're difficult to observe with the usual instruments.
14. Re:Impossible in this timespan by Anonymous Coward · 2009-03-02 03:12 · Score: 0
  
  ah. A Challenge. But who would want to be a head of a large govt backed organization like NASA where you would be too busy with the politics to get anything done.
15. Re:Impossible in this timespan by zobier · 2009-03-02 14:54 · Score: 1
  
  Dude, If I had a TARDIS -- Fuck NASA -- I'd be flying around the Universe picking up hotties!
  
  --
  Me lost me cookie at the disco.
16. Re:Impossible in this timespan by angster · 2009-03-05 06:42 · Score: 1
  
  But Dr. Who only gets exactly where he pleases when it satisfies the writers. Most of the time it seems that some sort of space-time vortex sucks him off-course, or the Tardis misbehaves, or other such circumstance landing him in the wrong space/time.
  I guess they just don't make Tardises the way they will.
Thirty metres by Anonymous Coward · 2009-03-01 10:07 · Score: 0

The Tunguska object would have been about that size. The article compares it to the October 7 2008 object, which was only a couple of metres across. Thats why it didn't get much attention.
1. Re:Thirty metres by MichaelSmith · 2009-03-01 10:37 · Score: 2, Informative
  
  That was me. Must have hit AC by mistake.
  
  --
  http://michaelsmith.id.au
2. Re:Thirty metres by Hooya · 2009-03-01 11:35 · Score: 2, Funny
  
  > That was me. Must have hit AC by mistake
  No, no.. the meteor didn't hit anything.. but thanks for flying by if it indeed was you.
Fourth by malkir · 2009-03-01 10:08 · Score: 1, Offtopic

C-C-C-COMBO BREAKER
1. Re:Fourth by Anonymous Coward · 2009-03-01 12:07 · Score: 3, Funny
  
  ^That this was modded interesting made me lose faith in humanity.
2. Re:Fourth by eleuthero · 2009-03-02 09:24 · Score: 2, Funny
  
  That it took until "fourth" to lose faith in humanity makes you a much more hopeful person than I--all it took for me was yet another "first post" troll
Another perspective by wjh31 · 2009-03-01 10:09 · Score: 1, Informative

radius of the earth is 6400km, so it will be at ten times the radius of the earth. It will experiance an acceleration from the earth of about 0.1m/s^2. In those few hours it will be greater than 13th magnitude it's velocity will change by about 1km/s or ~30000km/h from the force of the earth alone.
1. Re:Another perspective by MichaelSmith · 2009-03-01 10:16 · Score: 2, Interesting
  
  In those few hours it will be greater than 13th magnitude it's velocity will change by about 1km/s or ~30000km/h from the force of the earth alone.
  Most of which it will give back on the way out. So what is the net velocity change for the earth encounter?
  
  --
  http://michaelsmith.id.au
2. Re:Another perspective by wjh31 · 2009-03-01 10:29 · Score: 2, Insightful
  
  about Zero when integrated over enough orbits, but for this encounter, while the speed wont change by then end of the encounter, but the velocity will, i think
3. Re:Another perspective by MartinSchou · 2009-03-01 10:50 · Score: 5, Informative
  
  1 km/s is EXACTLY 3,600 km/h. Not roughly 30,000 km/h as you suggest.
4. Re:Another perspective by Overzeetop · 2009-03-01 11:12 · Score: 2, Insightful
  
  m2/m1xdelta-v, or diminishingly small; that's the useful part about using planetary passes to change velocity - they affect the planet in a negligible way. Kind of like driving to the store makes a negligible change in the CO2 in the atmosphere vs. walking. If all the asteroids started going for a joy ride, or taking vacation past earth every summer just for the fun of it, we'd start to notice. ;-)
  
  --
  Is it just my observation, or are there way too many stupid people in the world?
5. Re:Another perspective by John+Hasler · 2009-03-01 11:25 · Score: 1
  
  There will be a significant change in direction. How much kinetic energy it gains or loses depends on the details.
  
  --
  Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
A potential 3rd moon? by pecosdave · 2009-03-01 10:18 · Score: 2, Interesting

Assuming of course you count Cruithne as a moon. What happens once it passes our gravity?

--
The preceding post was not a Slashvertisement.
1. Re:A potential 3rd moon? by MartinSchou · 2009-03-01 10:56 · Score: 1
  
  5th, actually
  Known satelittes and quasi-satellites wrt Earth
  Moon
  Cruithne (Earth's first known quasi-satellites)
  2003 YN107
  (164207) 2004 GU9
2. Re:A potential 3rd moon? by madcat2c · 2009-03-01 14:32 · Score: 1
  
  Since its Diameter is 5Km, i would guess no.
another asteroid...another day by mikey177 · 2009-03-01 10:18 · Score: 1

they say that asteroids this size hit earth every month without any notice. I would be more worried about comets that we cant pick up till it gets closer to the sun and at that point if it is headed towards earth you only have around 6 months to a year
1. Re:another asteroid...another day by Anonymous Coward · 2009-03-01 10:31 · Score: 0
  
  It seems like with 6 months to a year's notice, NASA and the DoD would have a good chance of hitting it with whatever secret uber-nukes the US has hidden away.
  Does anyone know how feasible or likely that scenario is?
2. Re:another asteroid...another day by rubycodez · 2009-03-01 13:45 · Score: 1
  
  the U.S. has no such thing, the biggest bomb ever was soviet made
3. Re:another asteroid...another day by madcat2c · 2009-03-01 14:54 · Score: 1
  
  Lord knows the U.S. couldn't hide something of extreme military importance.
4. Re:another asteroid...another day by rubycodez · 2009-03-01 15:46 · Score: 1
  
  hide mostly meant "keep officially declared", plenty of early sightings of that bird.
  But very large nukes such as that Tsar bomb can't be put on even the largest of our rockets, just too damn heavy.
5. Re:another asteroid...another day by CrimsonAvenger · 2009-03-01 16:07 · Score: 1
  
  the U.S. has no such thing, the biggest bomb ever was soviet made
  The biggest ever detonated was Soviet made. I'm not sure who would know what the biggest ever built was, but I doubt seriously it's any of us.
  And besides, a 15 MT bomb would do nicely here. And we have those.
  Unless we decommissioned them as part of one of the SALTs. Anyone know?
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
6. Re:another asteroid...another day by CrimsonAvenger · 2009-03-01 16:10 · Score: 1
  
  "it won't be another Vietnam" -- Rummy
  Vietnam - ten years, 50,000 dead.
  Iraq - six years, less than 5000 dead.
  Looks like he was right.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
7. Re:another asteroid...another day by Anonymous Coward · 2009-03-01 17:38 · Score: 0
  
  How can you possibly say what the US has "hidden away". It's not as if they'd make their best stuff public knowledge.
8. Re:another asteroid...another day by Tony+Hoyle · 2009-03-02 01:42 · Score: 1
  
  The iraq death toll is nearing 100,000.
  Of course the official figures don't count 'uninteresting' people like anyone without an american accent.
9. Re:another asteroid...another day by CrimsonAvenger · 2009-03-02 05:55 · Score: 1
  
  The iraq death toll is nearing 100,000.
  Of course the official figures don't count 'uninteresting' people like anyone without an american accent.
  Sorry, was trying to compare like with like. The Vietnam Death toll I gave was also only Americans killed.
  If you'd rather include ALL deaths, it still looks like he was right though.
  Vietnam War civilian casualties, both sides (yes, the North Vietnamese killed South Vietnamese civilians in job lots too) were on the order of millions. They could have been as higher then five million, and one million is about the lower limit. Call it three million.
  Vietnamese soldiers, both sides: 1.3 million in round numbers.
  American soldiers: 58913 (officially). Since some are still MIA, they're not techincally dead yet.
  Total for Iraq (your numbers): 105000, including American losses.
  Total for Vietnam: somewhere between 2.4 million and 6.4 million.
  Still looks like he was right.
  
  --
  
  "I do not agree with what you say, but I will defend to the death your right to say it"
10. Re:another asteroid...another day by rubycodez · 2009-03-03 02:32 · Score: 1
  
  both you people entirely miss the point, Rumsfield was not referring to possible body count (though the real body count of the Iraq war is something over twice the official 100K estimate). And he was very wrong.
  That "war" was mismanaged
11. Re:another asteroid...another day by rubycodez · 2009-03-04 02:47 · Score: 1
  
  Rummy wasn't talking about body count. He was wrong in that it has become long and protracted with civil war and insurgency, with foreign powers coming in to supply and to wage war against our soldiers. And more and more division here at home over it.
What if by markov_chain · 2009-03-01 10:19 · Score: 1

Suppose the main (heavy) probe was sitting in GEO or something, but shot a lightweight harpoon into the meteor's orbit. Then the trick would be to get the tether to pay out quickly, and the main probe to slowly increase tension so it can accelerate into the meteor's orbit.

--
Tsunami -- You can't bring a good wave down!
1. Re:What if by evanbd · 2009-03-01 10:31 · Score: 1
  
  If you can only manage a few hundred m/s speed difference between the two, it's probably not worth doing -- rockets to provide that much delta-v just aren't that large or heavy, and this would be complicated, heavy, and new. If you want to do more than that, then you have a whole different problem -- making a harpoon work at several km/s sounds nontrivial, never mind the cable payout system or the mass of a cable that long (unless your probe can handle ridiculous accelerations, 1/2*a*t^2 means you have a very long -- aka heavy -- cable).
2. Re:What if by History's+Coming+To · 2009-03-01 12:08 · Score: 1
  
  There's a good description of that kind of maneuver in "Wheelers" http://bookshop.blackwell.co.uk/jsp/search_results.jsp?wcp=1&quicksearch=1&cntType=&searchType=keywords&searchData=9780743429023&x=0&y=0 by Ian Stewart and Jack Cohen. Except they use rocks fired from linear accelerators on the moon, but the same net-and-shock-absorber concept.
  
  --
  Please consider this account deleted, I just can't be bothered with the spam anymore.
obligatory by Anonymous Coward · 2009-03-01 10:35 · Score: 2, Funny

/ducks
1. Re:obligatory by Anonymous Coward · 2009-03-02 02:44 · Score: 0
  
  Swoosh!
2. Re:obligatory by mcgrew · 2009-03-02 05:34 · Score: 1
  
  /donald and /daffy?
  
  --
  Free Martian Whores!
Buzz vs. Non-buzz by DynaSoar · 2009-03-01 10:36 · Score: 5, Informative

Three days notice. 20 to 50 meter diameter. Assume it's dense rock and a vertical impact trajectory into the ocean (avg. 1000 m depth).
Impact energy 116 kT to 1.8 MT. Very near the lowest energy potential impact of the known NEOs, actually. Not relevant here since the object quite clearly misses. But if and when one doesn't miss, someplace is going to catch a small to medium nuke sized blast, and there won't be time to do squat about it.
My money says we'll have the capability to defend ourselves against such an impact. The second time.

--
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
1. Re:Buzz vs. Non-buzz by MichaelSmith · 2009-03-01 10:43 · Score: 1
  
  I have this idea in my head about a space transportation system based around tethers, solar sails and aerobraking. There are a lot of tricks you could do once attached to an object like this. You could convert angular momentum from the object into linear momentum by letting the asteroid swing you around then releasing at the appropriate moment. You could do a slingshot by pushing off the asteroid then retracting the tether at the appropriate moment.
  
  It could be a very hairy but profitable way to travel.
  
  --
  http://michaelsmith.id.au
2. Re:Buzz vs. Non-buzz by meringuoid · 2009-03-01 10:51 · Score: 1
  
  My money says we'll have the capability to defend ourselves against such an impact. The second time.
  We won't do anything about these things till there's a loss of life. There's a 70% chance it hits the ocean, and with 1MT energy? There's pretty good odds it will go unnoticed by anything but defence satellites.
  I'd guess we'll get near miss after near miss, we'll ignore Tunguska-scale impacts at sea and in the tundra and in the desert just like we ignored Shoemaker-Levy 9... Nobody will fund a serious defence until one of these things strikes a city.
  
  --
  Real Daleks don't climb stairs - they level the building.
3. Re:Buzz vs. Non-buzz by MichaelSmith · 2009-03-01 10:52 · Score: 1
  
  just like we ignored Shoemaker-Levy 9...
  
  In what way did we ignore Shoemaker-Levy 9? That wasn't our planet after all.
  
  --
  http://michaelsmith.id.au
4. Re:Buzz vs. Non-buzz by narcberry · 2009-03-01 12:15 · Score: 3, Funny
  
  There's only so much matter, after enough time, we don't have to worry about anymore collisions.
  I vote we wait it out.
  
  --
  Modding me -1 troll doesn't make me wrong.
5. Re:Buzz vs. Non-buzz by Frequency+Domain · 2009-03-01 17:17 · Score: 2, Insightful
  
  We won't do anything about these things till there's a loss of life. There's a 70% chance it hits the ocean, and with 1MT energy? There's pretty good odds it will go unnoticed by anything but defence satellites.
  
  You think sea strikes are harmless? The odds of actually hitting a city are pretty small, but the odds of hitting a chunk of water near enough to populated areas to cause tsunami damage are much larger since, according to NOAA, coastal counties in the continental US account for only 17% of land area but have 53% of the population. Imagine what a 10m or more surge from a tsunami could do to the Netherlands, or Miami, or New York. For comparison purposes, the Sumatra tsunami of 2004 was estimated to release around 20MT of energy at the surface, and produced as much as 30m surges hundreds of miles away from the epicenter.
6. Re:Buzz vs. Non-buzz by R3d+M3rcury · 2009-03-01 18:19 · Score: 1
  
  For comparison purposes, the Sumatra tsunami of 2004 was estimated to release around 20MT of energy at the surface, and produced as much as 30m surges hundreds of miles away from the epicenter.
  Okay. So that's 20 times the 1MT we're talking about. So that would be 1.5m surge.
  I think New York is safe.
7. Re:Buzz vs. Non-buzz by Frequency+Domain · 2009-03-01 19:42 · Score: 1
  
  I doubt the wave's amplitude scales linearly against energy, or cannonballs into a pool would produce negligible results.
  Somebody below gave a link to a site which calculates that the crater opened in the water could have a diameter of 1.4km. I'm inclined to believe you'd see more than a 1.5m surge if something punched a 1.4km hole in the ocean along the continental shelf.
8. Re:Buzz vs. Non-buzz by MtViewGuy · 2009-03-02 00:12 · Score: 1
  
  If what I've read about large meteor impacts is correct, a 30 meter sized meteor impacting the ground not only will have an explosive yield around that of the W88 warhead used on the Trident II missile (circa 475 kT), but also you have the highly dangerous issue of local fallout where the fallout is burning ash around 1,200 degrees F.! That right there will start massive firestorms many miles away from the point of impact.
9. Re:Buzz vs. Non-buzz by drinkypoo · 2009-03-02 01:16 · Score: 1
  
  Imagine what a 10m or more surge from a tsunami could do to the Netherlands, or Miami, or New York.
  
  I do every day, but it still never happens. :(
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
10. Re:Buzz vs. Non-buzz by Hognoxious · 2009-03-02 03:38 · Score: 1
  
  Nothing of value would be lost.
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Small english/metric error, I believe by scotts13 · 2009-03-01 10:51 · Score: 1

The slashdot post says twice the altitude of geosynchronous satellites. Maybe, but only if it was 32,000 miles, not kilometers. Geosynchronous orbit is 32,000 miles; this object will be at about 40,000 miles as correctly stated in the original article. Should be amended to remove geosynchronous, or to "just beyond geosynchronous orbit."
1. Re:Small english/metric error, I believe by John+Hasler · 2009-03-01 11:09 · Score: 2, Informative
  
  > Geosynchronous orbit is 32,000 miles...
  Geosynchronous orbit is 22,236 miles.
  
  --
  Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
2. Re:Small english/metric error, I believe by tux0r · 2009-03-01 11:39 · Score: 0
  
  > Geosynchronous orbit is 32,000 miles...
  
  Geosynchronous orbit is 22,236 miles.
  
  [citation needed]
  Surely the refutation is no more helpful to the reader if it's just your word against GP's...? :)
  
  --
  ( Redundancy is ) ^ n
3. Re:Small english/metric error, I believe by maxume · 2009-03-01 14:25 · Score: 1
  
  It depends on which one is correct.
  If the potential correction contains accurate information, it is far more helpful to the reader than the incorrect information, citation or not (even if all it does is prompt the reader to obtain a reliable source for the information).
  
  --
  Nerd rage is the funniest rage.
4. Re:Small english/metric error, I believe by Kjella · 2009-03-02 02:01 · Score: 1
  
  Surely the refutation is no more helpful to the reader if it's just your word against GP's...
  Quite many will throw out a wrong fact. Quite few will correct a right answer with a wrong answer. That's 90% proof to me. If I've consulted google and wikipedia it's 99% proof. If I needed 99.99% proof I'd check up an alledgely authoritative source. Then you have all the paranoid options.
  Slashdot is a discussion forum, not a source-citing masturbatory like wikipedia. Sources are great for hitting people with a clue-by-four if they keep insisting on something wrong but otherwise it's completely superflous. If in doubt, look it up yourself but there's no need to pester posters with them.
  
  --
  Live today, because you never know what tomorrow brings
5. Re:Small english/metric error, I believe by Hognoxious · 2009-03-02 03:40 · Score: 2, Funny
  
  Slashdot is a discussion forum, not a source-citing masturbatory like wikipedia.
  [citation needed]
  
  --
  Confucius say, "Find worm in apple - bad. Find half a worm - worse."
6. Re:Small english/metric error, I believe by Anonymous Coward · 2009-03-02 09:52 · Score: 0
  
  Slashdot is a discussion forum, not a source-citing masturbatory like wikipedia.[1]
  Citation given.
This is ghostwriter asking for Permission to Buzz by Joe+The+Dragon · 2009-03-01 10:55 · Score: 1

This is ghostwriter asking for Permission to Buzz the Earth.
Parent links to malicious site by Anonymous Coward · 2009-03-01 11:00 · Score: 3, Informative

Sturly is a redirection service similar to tinyurl. Luckily it provides a preview. The link wants to send you to the same "dragonslair" link that appeared in the 3D game without polygons story from earlier today.

Looking at the source of the page, it attempts to download a movie on eDonkey, change your AIM name, send off spam emails, open up lots more windows, and probably much more. It also moves the window around so you can't close it, and pops up messages when you try to alt+f4.

In short; DO NOT CLICK THE LINK.
1. Re:Parent links to malicious site by steelcaress · 2009-03-02 08:21 · Score: 1
  
  Not that I don't believe you (and actually, I thank you), but how did you determine this without getting nailed yourself? I understand how to view the source code, but...
2. Re:Parent links to malicious site by schmiddy · 2009-03-02 17:13 · Score: 1
  how did you determine this without getting nailed yourself? I understand how to view the source code, but...
  
  Download original link: wget -O sturly.html http://sturly.com/[OP's malicious link removed]
  Look at source code for sturly.html in your favorite text editor. See the link to http://www.on.[domain removed].org/dragonslair.html , near the text that says "This short url redirects to.."
  Download the URL redirect with wget: wget -O dragonslair.html http://www.on.[domain removed].org/dragonslair.html
  
  Open dragonslair.html in your text editor. See the "irc://" links? Those are attempting to automatically launch the user's IRC client and connect to troll channels. The news:// links attempt to open the user's Usenet browser and open some troll newsgroups. The mailto: links attempt to open a mail client and compose a message to a garbage troll address. A telnet and rlogin window also look to be opened, along with AIM windows (the aim: address) and the ed2k:// link links to a specific md5 on the ed2k network, some stupid troll movie I gather.
  I haven't bothered mucking with the Javascript source code, but I wouldn't be surprised if the web page tried to open all these links many times repeatedly, instead of just once. In other words, an annoying DOS on your computer (you'd have a ton of email, AIM, edonkey, etc. windows automatically launched).
  There's even a comment in the page, above an <object> tag that gives away:  Usually, malicious pages aren't so obvious about what the annoying/malicious behaviour is doing -- usually you have to wade through a whole shit-ton of javascript obfuscation just to see what the javascript code actually is.. and even the "plain" code has been run through an obfuscator stripping down variable and function names (similar to e.g. Google's javascript, if you look at it). So it's particularly easy to see what this page is doing.
  For our next lesson, we'll discuss how to analyze obfuscated malicious Javascript using WinXP+IE6 running safely in a VM. Tune in next week, kids. And remember, friends don't let friends run Windows on the bare metal.
  --
  http://cltracker.net -- powerful craigslist multi-city search
3. Re:Parent links to malicious site by mail2345 · 2009-03-03 19:37 · Score: 1
  
  How is parent informative?
  It should be funny.
  
  Though it did forget to mention a goatease/2g1c loader. Flashed to the BIOS.
4. Re:Parent links to malicious site by mail2345 · 2009-03-04 09:55 · Score: 1
  
  Never mind, didn't see other
Armageddon by Samah · 2009-03-01 11:05 · Score: 3, Funny

Quick, someone notify Bruce Willis!

--
Homonyms are fun!
You're driving your car, but they're riding their bikes there.
1. Re:Armageddon by Anonymous Coward · 2009-03-02 06:05 · Score: 0
  
  This time, I hope it's Ben Affleck that gets left behind...
Holy Crap! by binaryseraph · 2009-03-01 11:35 · Score: 1

quick where is the kool-aid?!
Re:This is ghostwriter asking for Permission to Bu by Anonymous Coward · 2009-03-01 12:02 · Score: 1, Informative

I think it was supposed to be Ghostrider. As in, from "Ghostriders in the sky."
Negative Ghostrider, pattern is full. .....
GODDAMMIT!
Close call by mc1138 · 2009-03-01 12:05 · Score: 4, Interesting

While right now 64,000 puts it fairly far out in terms of all the junk orbiting the earth, it is significantly closer than the moon is. Even if it still missed the earth, just a few thousand kilometers closer and it could reek havoc on all the man-made junk spinning around the Earth. How much potential damage/debris could that cause?

--
The musings of just another geek and his junk.
1. Re:Close call by Nyeerrmm · 2009-03-01 12:44 · Score: 2, Insightful
  
  Without any actual analysis, I'll go out on a limb and estimate it would cause as much havoc as any large man-made piece of junk out there, like say a dead Soviet satellite. A much larger asteroid would be a different story, since not only would it have a larger footprint, but would also have hard-to-predict gravitational effects on all the satellites that got too near it. Of course, we're doing a pretty good job of detecting larger NEOs now... Apophis is the most problematic, mostly because we simply don't have high enough precision knowledge of its position to know where it will be in 2029 and 2036.
2. Re:Close call by swillden · 2009-03-01 12:52 · Score: 1
  
  Apophis is the most problematic, mostly because we simply don't have high enough precision knowledge of its position to know where it will be in 2029 and 2036.
  Well, that and its habit of enslaving humans to feed its goa'uld power trip fantasies.
  
  --
  Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
3. Re:Close call by Anonymous Coward · 2009-03-01 13:09 · Score: 0
  
  Ummm, speaking of dead Soviet satellites, how many of them are still in some sort of Molyniya orbit (sorry about the probably misspelling - I'm referring to the highly ellipitical orbits) ?
  ISTR there were even some ham satellites that were launched into highly elliptical orbits that were "visible" for 10-12 hours/day from one hemisphere or the other, so I'm sure they were wayyyyy up there somewhere.
4. Re:Close call by Anonymous Coward · 2009-03-01 18:32 · Score: 0
  
  Even if it still missed the earth, just a few thousand kilometers closer and it could reek havoc on all the man-made junk spinning around the Earth.
  Thank god that in space, no one can smell you. Whew.
5. Re:Close call by HTH+NE1 · 2009-03-02 05:55 · Score: 1
  
  "The year, 1994. From out of space, comes a runaway planet, hurtling between the Earth and the Moon, unleashing cosmic destruction. Man's civilization is cast in ruin.
  "Two thousand years later, Earth is reborn. A strange new world rises from the old. A world of savagery, super-science, and sorcery.
  "But one man bursts his bonds to fight for justice. With his companions, Ookla the Mok and Princess Ariel, he pits his strength, his courage, and his fabulous Sunsword against the forces of evil. He is Thundarr, the Barbarian!"
  
  --
  Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Another one from Klendathu... by allcoolnameswheretak · 2009-03-01 12:16 · Score: 3, Funny

Their aim is getting better. They will hit us eventually if we don't do something about those Bugs, soon.
1. Re:Another one from Klendathu... by HTH+NE1 · 2009-03-02 06:00 · Score: 1
  
  Their aim is getting better. They will hit us eventually if we don't do something about those Bugs, soon.
  Would you like to know more?
  
  --
  Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
So, I used a calc on the impact by Ralph+Spoilsport · 2009-03-01 12:29 · Score: 5, Informative

the calculator can be found here:
http://www.lpl.arizona.edu/impacteffects/
And the results are (assumed that you are 2000km from impact - if it hit it would be in the ocean...)
Your Inputs: Distance from Impact: 2000.00 km = 1242.00 miles
Projectile Diameter: 30.00 m = 98.40 ft = 0.02 miles
Projectile Density: 8000 kg/m3
Impact Velocity: 17.00 km/s = 10.56 miles/s
Impact Angle: 90 degrees
Target Density: 1000 kg/m3
Target Type: Liquid Water of depth 100.00
meters, over typical rock.
Energy: Energy before atmospheric entry: 1.63 x 1016 Joules = 3.90 MegaTons TNT
The average interval between impacts of this size somewhere on Earth is 314.0 years
Atmospheric Entry: The projectile begins to breakup at an altitude of 14100 meters = 46100 ft
The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 10.8 km/s = 6.7 miles/s The impact energy is 6.58 x 1015 Joules = 1.57 MegaTons.
The broken projectile fragments strike the ground in an ellipse of dimension 0.151 km by 0.151 km
Major Global Changes: The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Crater Dimensions:
What does this mean?
The crater opened in the water has a diameter of 1.4 km = 0.866 miles
For the crater formed in the seafloor: Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.
Transient Crater Diameter: 670 m = 2200 ft
Transient Crater Depth: 237 m = 777 ft
Final Crater Diameter: 837 m = 2750 ft
Final Crater Depth: 179 m = 586 ft
The crater formed is a simple crater
The floor of the crater is underlain by a lens of broken rock debris (breccia) with a maximum thickness of 82.8 m = 272 ft.
At this impact velocity ( Thermal Radiation: What does this mean?
At this impact velocity ( Seismic Effects: What does this mean?
The major seismic shaking will arrive at approximately 400 seconds.
Richter Scale Magnitude: 4.4
Mercalli Scale Intensity at a distance of 2000 km:
Nothing would be felt. However, seismic equipment may still detect the shaking.

--
Shoes for Industry. Shoes for the Dead.
1. Re:So, I used a calc on the impact by RedDevilCG · 2009-03-01 21:59 · Score: 1
  
  Major Global Changes: The Earth is not strongly disturbed by the impact and loses negligible mass.
  How the hell could the Earth lose mass from absorbing space rocks in the first place? Loses = gains?
2. Re:So, I used a calc on the impact by Kugala · 2009-03-02 01:34 · Score: 1
  
  Large enough impacts will throw mass back into orbit. See the moon for reference.
3. Re:So, I used a calc on the impact by firmamentalfalcon · 2009-03-02 01:39 · Score: 1
  
  The moon is lost mass, I believe.
4. Re:So, I used a calc on the impact by dargaud · 2009-03-02 03:45 · Score: 1
  
  Transient Crater Depth: 237 m [...] Richter Scale Magnitude: 4.4
  Huh ? You make a 200m deep hole in the ground in one second and it doesn't even register as a worthwhile earthquake ?!? There must be something wrong here.
  
  --
  Non-Linux Penguins ?
5. Re:So, I used a calc on the impact by Anonymous Coward · 2009-03-02 04:24 · Score: 0
  
  How about launch a prob to a head one collision. Now what's the point of doing this? Have the prob contain the little black box as we do on airplanes. They seem to survive any crash. Then we can have the little black box. Send data to our USA base station.
6. Re:So, I used a calc on the impact by Savantissimo · 2009-03-02 12:28 · Score: 1
  
  2000 km away the earthquake magnitude is still 4.4, I believe.
  
  --
  "Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
I for one... by fullymodo · 2009-03-01 13:44 · Score: 1

...welcome our new 45 double-D overlords.

--
In the land of the blind, the one eyed man still has no depth perception.
Re:A good use of the Gov't Money by antirelic · 2009-03-01 14:52 · Score: 1

Let me ask the resident experts: With all the different telescopes that litter the earth, how is it that we miss these types of objects coming so close to our planet? I know that space is vast (practically beyond rational imagination), but is there a way to observe a region of space encompassing several days/weeks/months with objects traveling at a certain speed? What would those costs be? (I bet it would be under 700 Billion USD)
I found this article pretty interesting about a space based constellaton of satellites using radar to track objects on the ground. How about something like this pointing away from earth?:
http://www.globalsecurity.org/space/systems/sr.htm
I think this would be an excellent time for the US to jump back in the lead in science and technology. Take that money going into ideologically based spending, and shove it into space systems that will have actual use. Create methods of early detection of earth impacting objects, and standby means to intercept. The "space industrial complex" could lead to high tech jobs that create a high tech industry that will attract top talent from around the world at rates that rival the early 20th century.

--
20th century Marxism is not progress...
Re:A good use of the Gov't Money by John+Hasler · 2009-03-01 15:54 · Score: 1

It is going to require an 8" telescope to see it at 64,000 km. Brightness is inversely proportional to the square of distance. Extrapolate.

--
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
What if it waits in orbit? by Mathinker · 2009-03-01 18:14 · Score: 2, Interesting

If you had several such pre-built probes waiting in orbit, you would have a much better chance, no? The probes would have the advantage that they're already out of the deepest part of Earth's gravity well, and that you could choose the one whose orbit is best. I would think that with only two or three you would be able to do what he wanted.
OTOH, I'm not convinced it would be cost-effective. Depends on how often do asteroids pass by close enough to make it worth our while (and how often they're worth piggy-backing upon), versus the cost saved for getting where you want to go.
Purposes by MickLinux · 2009-03-02 03:09 · Score: 1

I can think of a few purposes.
(1) Set automated computer/video aboard the asteroid, and search out other asteroids. Plot trajectories, and relay info back to earth.
(2) Use asteroid mounted telescopes to take photos of (and out of) the solar system at different times and angles. These are occasional, but are all preset according to time, date, and direction, and match from one asteroid to another. Transmit data to other asteroid riding probes, and any time a probe comes close to earth, transmit that info back to earth. Build a giant parallax multocular telescope network. With the multiple images, we should be able to spot many other in-system asteroids, moons, planetoidal asteroids, and whatnot. With the greater distance between viewing points, we should also be able to get more detail of the extra-solar systems.

--
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
1. Re:Purposes by honkycat · 2009-03-03 01:32 · Score: 1
  
  While the science you propose might be interesting, your probe obtains no benefit from actually being on the asteroid in any way (other than the incorrect supposition that survivably landing on an asteroid is somehow easier than simply matching speed and position at a time when there is no asteroid there). There's no reason to expect that any particular asteroid is going to travel somewhere interesting, so there's just no incentive to hurry up to ride it. That asteroid is not going to go anywhere that your probe won't go on its own!
  If you want to explore the asteroid zone with a self-assembling network of probes with no attitude control, then just let them fly freely. Really, really, being on the asteroid doesn't buy you anything.
2. Re:Purposes by MickLinux · 2009-03-04 00:24 · Score: 1
  
  Okay, you have a point. How about this one, then?
  You design a probe to split into two equal sections on a very long tether.
  Now, you set them in orbit, and get them spinning on the long tether.
  When an asteroid flies by, the one nearest the asteroid matches speed, and anchors onto the asteroid.
  Now, the other probe detatches as the velocity vector swings around perpendicular to the path of the asteroid. Because of conservation of momentum, the second is going to obtain a velocity that is proportional to the asteroid velocity, times the ratios of the asteroid to spacecraft.
  It will crack the whip, so to speak.
  Quick interstellar probe.
  
  --
  Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
Not necessarily. by tjstork · 2009-03-02 03:54 · Score: 1

If we have the deltaV to land on the rock, then we have the deltaV to match its orbit without bothering to land on it. So why waste time with the landing?
Well, you could fire a bullet straight up. If it peaked at say a mile up, its velocity would be zero, but, it could still hit a plane regardless of its velocity if you timed it right.
In the case of the asteroid, we could theoretically, anyway, shoot up something to an altitude of 64k km, have it "hit" the asteroid, and then continue on its merry way. That would be some pretty fancy shooting, but you wouldn't -need- to reach escape velocity. Granted, the old probe would be impacted by something that has twenty times the velocity of a rifle bullet and billions of times the mass, so it would be a short visit. IF he wanted to train for this mission, perhaps we could reactivate an Iowa class battleship and have it fire a full broadside into his chest. I think that would only be a billionth of the forces involved of getting hit by a giant asteroid, but, at least its practice.

--
This is my sig.
Why Not Tahiti? by ninjagin · 2009-03-02 04:02 · Score: 1

If it's going to be closest to Tahiti, why isn't that the best place to observe it from? Papeete, perhaps?

--
.. pa-ra-bo-la, pa-ra-bo-la, 2 pi R, 2 pi R, where's your latus rectum, where's your latus rectum, 2 pi R
Re:This is ghostwriter asking for Permission to Bu by Anonymous Coward · 2009-03-02 05:58 · Score: 0

uh - negative ghostwriter - the pattern is full...
looking to get hit? by cdpage · 2009-03-02 05:59 · Score: 1

Does anyone else out there look forward to a day we get hit by something semibig?...

I'm not talking end of days... but something big that most everyone on earth would be affected even just a little. Hopefully bringing us closer together... as humans.

I'm not saying we can't evacuate the area's... i'd rather not see anyone get killed... but relocated, change the way things work...
Thundarr??? by Anonymous Coward · 2009-03-02 06:51 · Score: 0

Isn't this EXACTLY how Thundarr the Barbarian starts?
Bungie Cords! by Anonymous Coward · 2009-03-02 08:12 · Score: 0

Bungie Cords! Harpoon it and Waahoooo!
Re:nothing of value would be lost by Anonymous Coward · 2009-03-02 10:04 · Score: 0

Imagine what a 10m or more surge from a tsunami could do to the Netherlands, or Miami, or New York.

Nothing of value would be lost.
Not true. Where would we get Tulips from during the other 11 months of the year?
The more ominous thought... by docwatson223 · 2009-03-02 10:37 · Score: 1

2 days to say "Oh shit!" "I love you!" and "Goodbye" is what it could have been if this was something much bigger and closer. How the heck do we detect something in that circumstance and do we say anything if we do?
Re:A good use of the Gov't Money by Savantissimo · 2009-03-02 11:58 · Score: 1

There's a 42 meter European scope that should be complete by 2016, 8" ~=0.2m, telescope diameter is linearly related to distance of detection of a given brightness object, so 12 or 13 million km, so that's effective warning for a 30m asteroid for purposes of orderly evacuation, but not for a space mission.
Destruction goes roughly as the cube of the asteroid diameter while brightness rises as the square, so there's an overall inverse relationship between our ability to detect (using a given size of telescope) and the danger posed. In other words odds are we won't see the big one until it's too late.
Also, it's a big sky. If it comes from a weird direction we very likely won't see it at all. It'll also have a bigger relative velocity and thus much more destructive power (E=m*v^2.)
Telescopes are cheap, though. The risks are existential - the human race could be wiped out. But even on an individual accounting, leaving aside the risk to the human race, if there's a 1 in 10^8 risk of a KT-like event per year that would kill 10^9.8 people, then that's 6800 deaths per year over the long haul. If a life is worth a million bucks to save, then we should be spending at least 6.8 billion a year on asteroid detection and response - actually much more than that counting the danger from the much more numerous smaller asteroids.

--
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Actually, it's within 40,000 miles by Bob+Uhl · 2009-03-02 13:33 · Score: 1

That's 40,000 miles for those of us using standard units.
'splat' & 'crunch' by Anonymous Coward · 2009-03-03 22:13 · Score: 0

If you try to catch an asteroid as it passes, words like 'splat' or 'crunch' are appropriate.
In space, nobody can hear your onomatopoeias!