3 ms·

> If you have two race cars going in around a track and at one from the other, it still appears to be moving relative to the stands. Right. Now put the stands

by mike_d 2y ago

> If you have two race cars going in around a track and at one from the other, it still appears to be moving relative to the stands. Right. Now put the stands on another planet and you start to understand the problem. We need to be able to see an asteroid at a minimum of of 3-4x the distance between the earth and the sun to have enough time to do anything about it based on the average speed of 40k mph. Now keep in mind that at that distance you are looking for something as "tiny" as 60 miles across, the accepted size that would unquestionably end life on earth. Something ~1km across would cause mass famine. In 1908 an asteroid less than 200 feet across flattened 80 million trees over an 830 square mile area.

s1artibartfast 2y ago
Even if the stands are far away, even light years away, you pan through 360° every year. The fact that the background is far away means that it moves even quicker relative to a nearby object in a rotational frame. If you spin around in a circle, hold your hand out and look at it, it will be moving very quickly against a distant background, like the horizon. My point is that the distance to the background helps detection, not hurts it. If the background was nearby and co-rotating around the Sun, detection would be a near impossible.
delta_p_delta_x 2y ago
Firstly, the several different unit systems in this comment give me a headache. Next, > We need to be able to see an asteroid at a minimum of of 3-4x the distance between the earth and the sun to have enough time to do anything about it based on the average speed of 40k mph. Not really. The important variable is not distance, but rather the mass and velocity vector. There could exist an asteroid that is currently barely 1 moon orbit away (~400 000 km), but has a velocity vector almost equal to that of Earth's. This asteroid could then be predicted to impact upon the next close encounter with Earth. In general, the more distant the predicted impact date, the less the delta-v required to push the asteroid off its current path and avoid an impact in future. > Now keep in mind that at that distance you are looking for something as "tiny" as 60 miles across NASA and ESA have databases of some 35000 near-Earth asteroids, and many of them are orders of magnitude smaller than 100 km[1]. Our detection capability has significantly improved since efforts first started in the 1980s. Asteroid impact avoidance is amongst the few natural disasters humanity has the technological, financial, and engineering capability to completely avoid. We have both the firepower and the lift capability (if not now, then in the near future, dictated by the urgency of the asteroid impact) to deflect even a 12 km, Chicxulub-size impactor if detected sufficiently early. About 5-10 years' warning would be enough time for a large nuclear device to deflect such an asteroid, which would be a major achievement for humanity. [1]: https://cneos.jpl.nasa.gov/sentry/ https://cneos.jpl.nasa.gov/sentry/
- funcDropShadow 2y ago
  > About 5-10 years' warning would be enough time for a large nuclear device to deflect such an asteroid The asteroid in this article was detected 2 weeks ago.
  - delta_p_delta_x 2y ago
    Precisely why we ought to step up our detection.
    - dorkNiner 2y ago
      Really, we should have a moon base, 6 years ago. This makes me very anxious. We have all our eggs are in one basket. As for detection there's some of them are coming from the other side of the sun, the one that Jupiter throw at us, It would be good to have a few more detection at L4, L3, It would be good to know what part of the earth is going to get hit. And evacuate them. Having a moon base off planet would be able to make all this coordination possible, because the amount of chaos that it would cause.So it needs a large gain antenna like the one that's in Australia that the Intuitive Machines lander low gain antenna was able to make two way contact with. The same one that was used to televise the Apollo missions. I just can't, I can't emphasize enough the advantages to working and living on the moon. Shift all energy production all these experiments terraforming and such eco engineering To there just terraform one crater and start growing some plants . It shouldn't have been done so many years ago. It could be done with one pre-supply mission with a Falcon 9 and an Oberth Pumping orbit and then followed by a manned mission. Where the falcon heavy and dragon? The mayby recovered the second stage on the moon. It's just been over thought, overly planned. I mean, against nature, we're nothing. It's impractical to think that we can. can't stop a meteor. We're never going to see it coming. We don't have five years to plan that I mean. I'm even surprised that any of the simulations converge . You know, don't need to be adjusted. We don't even have gravity physics consensus. I can't be done on a Earth because it becomes someone else's problem far away because it usually backfires diffuses through the air in the sea. It does not happen on the moon. So I mean, you can make this terrible meltdown reactor and then just leave. Leave it in a crater. Those gamma rays are not going anywhere except up. I just put a thing that says no fly zone over it. Seems that we put a lot of effort and money into these overly ambitious projects like going to Mars, which has absolutely no practical advantage when leaving the moon up there, unused. I mean, this isn't about Space tourism t's about survival. making the moon an exporter. It has everything that we don't have, but that we're running out of, rare earth minerals. oxygen. The only thing that's missing is carbon dioxide. And we're going to be bringing that. And as soon as the plans we grow up there, using that 24/7 solar. solar power. and have a greenhouse. All we have to do is breathe the air they make. They can extract oxygen from the regular and we can do it too with heat. And we can sublimate iron and build stuff. We can, we can figure out how to sublimate titanium from titanium dioxide. I mean, the conditions are so ideal. We we would go there cause it because we think it's easy. When we go there because we thought it would be easy, right? But right now, I think we think is is going to be a lot harder than it really is. There's sweet spots on them. Lunar S pole that are just 20 degrees C. To send stuff back down to Earth, you just have to shoot it at 2400 kph The railgun. will fall back down to Earth will take long. Superconductor is in permanently shadowed craters are almost sort of Ambient temperature. if not already. Type B, type 2 or whatever.
Mistletoe 2y ago
>to have enough time to do anything about it Do we have a real plan for what we would do? What can we do? Do we even have nuclear weapons that can target outer space etc.?

by mike_d 2y ago

s1artibartfast 2y ago

Even if the stands are far away, even light years away, you pan through 360° every year. The fact that the background is far away means that it moves even quicker relative to a nearby object in a rotational frame. If you spin around in a circle, hold your hand out and look at it, it will be moving very quickly against a distant background, like the horizon. My point is that the distance to the background helps detection, not hurts it. If the background was nearby and co-rotating around the Sun, detection would be a near impossible.

delta_p_delta_x 2y ago

Firstly, the several different unit systems in this comment give me a headache. Next, > We need to be able to see an asteroid at a minimum of of 3-4x the distance between the earth and the sun to have enough time to do anything about it based on the average speed of 40k mph. Not really. The important variable is not distance, but rather the mass and velocity vector. There could exist an asteroid that is currently barely 1 moon orbit away (~400 000 km), but has a velocity vector almost equal to that of Earth's. This asteroid could then be predicted to impact upon the next close encounter with Earth. In general, the more distant the predicted impact date, the less the delta-v required to push the asteroid off its current path and avoid an impact in future. > Now keep in mind that at that distance you are looking for something as "tiny" as 60 miles across NASA and ESA have databases of some 35000 near-Earth asteroids, and many of them are orders of magnitude smaller than 100 km[1]. Our detection capability has significantly improved since efforts first started in the 1980s. Asteroid impact avoidance is amongst the few natural disasters humanity has the technological, financial, and engineering capability to completely avoid. We have both the firepower and the lift capability (if not now, then in the near future, dictated by the urgency of the asteroid impact) to deflect even a 12 km, Chicxulub-size impactor if detected sufficiently early. About 5-10 years' warning would be enough time for a large nuclear device to deflect such an asteroid, which would be a major achievement for humanity. [1]: https://cneos.jpl.nasa.gov/sentry/ https://cneos.jpl.nasa.gov/sentry/

funcDropShadow 2y ago
> About 5-10 years' warning would be enough time for a large nuclear device to deflect such an asteroid The asteroid in this article was detected 2 weeks ago.
- delta_p_delta_x 2y ago
  Precisely why we ought to step up our detection.
  - dorkNiner 2y ago
    Really, we should have a moon base, 6 years ago. This makes me very anxious. We have all our eggs are in one basket. As for detection there's some of them are coming from the other side of the sun, the one that Jupiter throw at us, It would be good to have a few more detection at L4, L3, It would be good to know what part of the earth is going to get hit. And evacuate them. Having a moon base off planet would be able to make all this coordination possible, because the amount of chaos that it would cause.So it needs a large gain antenna like the one that's in Australia that the Intuitive Machines lander low gain antenna was able to make two way contact with. The same one that was used to televise the Apollo missions. I just can't, I can't emphasize enough the advantages to working and living on the moon. Shift all energy production all these experiments terraforming and such eco engineering To there just terraform one crater and start growing some plants . It shouldn't have been done so many years ago. It could be done with one pre-supply mission with a Falcon 9 and an Oberth Pumping orbit and then followed by a manned mission. Where the falcon heavy and dragon? The mayby recovered the second stage on the moon. It's just been over thought, overly planned. I mean, against nature, we're nothing. It's impractical to think that we can. can't stop a meteor. We're never going to see it coming. We don't have five years to plan that I mean. I'm even surprised that any of the simulations converge . You know, don't need to be adjusted. We don't even have gravity physics consensus. I can't be done on a Earth because it becomes someone else's problem far away because it usually backfires diffuses through the air in the sea. It does not happen on the moon. So I mean, you can make this terrible meltdown reactor and then just leave. Leave it in a crater. Those gamma rays are not going anywhere except up. I just put a thing that says no fly zone over it. Seems that we put a lot of effort and money into these overly ambitious projects like going to Mars, which has absolutely no practical advantage when leaving the moon up there, unused. I mean, this isn't about Space tourism t's about survival. making the moon an exporter. It has everything that we don't have, but that we're running out of, rare earth minerals. oxygen. The only thing that's missing is carbon dioxide. And we're going to be bringing that. And as soon as the plans we grow up there, using that 24/7 solar. solar power. and have a greenhouse. All we have to do is breathe the air they make. They can extract oxygen from the regular and we can do it too with heat. And we can sublimate iron and build stuff. We can, we can figure out how to sublimate titanium from titanium dioxide. I mean, the conditions are so ideal. We we would go there cause it because we think it's easy. When we go there because we thought it would be easy, right? But right now, I think we think is is going to be a lot harder than it really is. There's sweet spots on them. Lunar S pole that are just 20 degrees C. To send stuff back down to Earth, you just have to shoot it at 2400 kph The railgun. will fall back down to Earth will take long. Superconductor is in permanently shadowed craters are almost sort of Ambient temperature. if not already. Type B, type 2 or whatever.

Mistletoe 2y ago

>to have enough time to do anything about it Do we have a real plan for what we would do? What can we do? Do we even have nuclear weapons that can target outer space etc.?