4 ms·

I think you overestimate the effect current technology can have on a meteor large enough to significantly dent the human population. Some of the objects mention

by lmkg 16y ago

I think you overestimate the effect current technology can have on a meteor large enough to significantly dent the human population. Some of the objects mentioned in the article are on the order of hundreds of kilometers. Mountains aren't even on the same scale as that. It's beyond our ability to even scratch.

btilly 16y ago
I think you underestimate the value of stopping smaller impacts. http://en.wikipedia.org/wiki/Impact_event#Sizes_and_frequencies http://en.wikipedia.org/wiki/Impact_event#Sizes_and_frequenc... claims that an incident on the size of the Tunguska event (would could take out a large city) happens every thousand years, and to prevent it we need to move an object with a diameter of 50 m or so. A object on this scale might be in the 10,000,000 kg range. We'd like to deflect it 6000 km or so (ie make it miss the Earth). We have about 600,000,000 seconds to do so. If we can give it a sideways momentum of 100,000 kg*m/s, we'll be fine. While difficult, this may be within our means. (Tapping it with a nuclear bomb is only the most obvious.)
- acqq 16y ago
  The major problem of nuking something like that is that you can get more pieces that are out of the control. The goal is just to deflect. It's harder than it appears.
  - btilly 16y ago
    I'm aware of that problem. However it turns out that if the pieces you get are small enough, then they will individually burn up in the atmosphere without causing damage. Moving most of a 50m rock out of the way and creating a bunch of small debris in the process is probably OK because the debris pieces are unlikely to be big enough to get through the atmosphere. (Satellites in orbit would be put at increased risk.) Attempting the same on a 500m rock would be a different story.
    - rbanffy 16y ago
      Not only that - if you blast the thing into small pieces, most of them may miss the Earth completely. You will still have to track a lot more objects, but between being dead and having to fund such a project, I am certainly in favor of #2
      - jacquesm 16y ago
        How do you feel about funding the missile defense shield? (and starwars?)
        rbanffy 16y ago
        They are completely different things. Star wars was meant to intercept immediate threats minutes after detection with light sub-orbital missiles with conventional warheads. A deep space shield would be Energia or Delta IV-class boosters with high-yield nuclear payloads meant to intercept targets years away months after detection on varied mission profiles adapted to the composition of the specific threat. It's a completely different game.
- jacquesm 16y ago
  You make it sound so easy :) Just matching direction and velocity with a specific 50 m asteroid alone would be a major technological feat, currently not within our capabilities. Galileo did a 'flyby' of an asteroid but the relative speed at the closest approach was still 8 Km/second. And that was an asteroid 18 Km in diameter, which we passed at more than 5,000 Km. The best we've done is this: http://en.wikipedia.org/wiki/NEAR_Shoemaker http://en.wikipedia.org/wiki/NEAR_Shoemaker A landing on a near earth asteroid, 34 Km across, with a 56 Kg payload. Eros is one of the 'easiest' (for want of a better term) asteroids you might want to visit. The two asteroids this article is about were discovered last week and are here now.
  - btilly 16y ago
    What part of while difficult, this may be within our means do you interpret as meaning easy? The person I was replying to was making the argument that there is no point to trying to categorize these things because we can't possibly do anything about anything we learn. My point is that the most common objects which can potentially cause significant damage are small enough that we could, given enough warning, plausibly do something about them.
  - rbanffy 16y ago
    > You make it sound so easy :) It's hard and expensive. OTOH, given enough funding (and I am quite sure that would be a small problem) it can be solved. It's likely we would have Apollo-sized timeframes to deal with the problem. It seems well within our capabilities.

by lmkg 16y ago

btilly 16y ago

I think you underestimate the value of stopping smaller impacts. http://en.wikipedia.org/wiki/Impact_event#Sizes_and_frequencies http://en.wikipedia.org/wiki/Impact_event#Sizes_and_frequenc... claims that an incident on the size of the Tunguska event (would could take out a large city) happens every thousand years, and to prevent it we need to move an object with a diameter of 50 m or so. A object on this scale might be in the 10,000,000 kg range. We'd like to deflect it 6000 km or so (ie make it miss the Earth). We have about 600,000,000 seconds to do so. If we can give it a sideways momentum of 100,000 kg*m/s, we'll be fine. While difficult, this may be within our means. (Tapping it with a nuclear bomb is only the most obvious.)

acqq 16y ago
The major problem of nuking something like that is that you can get more pieces that are out of the control. The goal is just to deflect. It's harder than it appears.
- btilly 16y ago
  I'm aware of that problem. However it turns out that if the pieces you get are small enough, then they will individually burn up in the atmosphere without causing damage. Moving most of a 50m rock out of the way and creating a bunch of small debris in the process is probably OK because the debris pieces are unlikely to be big enough to get through the atmosphere. (Satellites in orbit would be put at increased risk.) Attempting the same on a 500m rock would be a different story.
  - rbanffy 16y ago
    Not only that - if you blast the thing into small pieces, most of them may miss the Earth completely. You will still have to track a lot more objects, but between being dead and having to fund such a project, I am certainly in favor of #2
    - jacquesm 16y ago
      How do you feel about funding the missile defense shield? (and starwars?)
      - rbanffy 16y ago
        They are completely different things. Star wars was meant to intercept immediate threats minutes after detection with light sub-orbital missiles with conventional warheads. A deep space shield would be Energia or Delta IV-class boosters with high-yield nuclear payloads meant to intercept targets years away months after detection on varied mission profiles adapted to the composition of the specific threat. It's a completely different game.
jacquesm 16y ago
You make it sound so easy :) Just matching direction and velocity with a specific 50 m asteroid alone would be a major technological feat, currently not within our capabilities. Galileo did a 'flyby' of an asteroid but the relative speed at the closest approach was still 8 Km/second. And that was an asteroid 18 Km in diameter, which we passed at more than 5,000 Km. The best we've done is this: http://en.wikipedia.org/wiki/NEAR_Shoemaker http://en.wikipedia.org/wiki/NEAR_Shoemaker A landing on a near earth asteroid, 34 Km across, with a 56 Kg payload. Eros is one of the 'easiest' (for want of a better term) asteroids you might want to visit. The two asteroids this article is about were discovered last week and are here now.
- btilly 16y ago
  What part of while difficult, this may be within our means do you interpret as meaning easy? The person I was replying to was making the argument that there is no point to trying to categorize these things because we can't possibly do anything about anything we learn. My point is that the most common objects which can potentially cause significant damage are small enough that we could, given enough warning, plausibly do something about them.
- rbanffy 16y ago
  > You make it sound so easy :) It's hard and expensive. OTOH, given enough funding (and I am quite sure that would be a small problem) it can be solved. It's likely we would have Apollo-sized timeframes to deal with the problem. It seems well within our capabilities.