NASA tests planetary defense system 👽🌏🪐💫

**WillBrink** · 09-27-22, 09:48

Good summary by the BBC of small proof of concept test for dealing with future large objects that will come our way:

**georgeib** · 09-27-22, 10:25

I think maybe I lack imagination, because although I see this as a very cool proof of concept academic exercise, I don't see this ever practically working. Any asteroid or comet of sufficient mass to pose a threat to life on Earth, will not be dissuaded so easily. I'm not a physicist, but I do know how to do basic math, and it seems to me that the amount of mass or force necessary to significantly alter a massive object's path is going to be much more than we can muster.

In my mind, it's not that we are limited by current technology, per se, rather that the laws of physics and our ability to bring enough mass to bear are the limiting factors. I can't help but compare us to a moth trying to alter the trajectory of a fully loaded 18 wheeler traveling at 100 mph by smashing itself into the windshield. In theory, that moth's mass DID alter that truck's trajectory, but in reality it may as well not have for all the difference it would make.

The big take away from the video seems to be that they can actually hit the asteroid at all. In itself an amazing accomplishment. Very cool.

**WillBrink** · 09-27-22, 10:32

Originally Posted by georgeib

I think maybe I lack imagination, because although I see this as a very cool proof of concept academic exercise, I don't see this ever practically working. Any asteroid or comet of sufficient mass to pose a threat to life on Earth, will not be dissuaded so easily. I'm not a physicist, but I do know how to do basic math, and it seems to me that the amount of mass or force necessary to significantly alter a massive object's path is going to be much more than we can muster.

In my mind, it's not that we are limited by current technology, per se, rather that the laws of physics and our ability to bring enough mass to bear are the limiting factors. I can't help but compare us to a moth trying to alter the trajectory of a fully loaded 18 wheeler traveling at 100 mph by smashing itself into the windshield. In theory, that moth's mass DID alter that truck's trajectory, but in reality it may as well not have for all the difference it would make.

The big take away from the video seems to be that they can actually hit the asteroid at all. In itself an amazing accomplishment. Very cool.

The key factor there is, the farther out it is, the less change in trajectory required for it to miss earth, so early warning if the key there. Far enough out, a tiny alteration in trajectory is all that's needed. But, we best start now to figure that out, and that's what is happening as it's not an matter of if, but when, we are on directly collision course with something that will wipe us out. Meanwhile, people give a damn about useless nonsense, sports scores, etc, and clueless about that, likely didn't even know about this impressive mission.

**georgeib** · 09-27-22, 10:43

Originally Posted by WillBrink

The key factor there is, the farther out it is, the less change in trajectory required for it to miss earth, so early warning if the key there. Far enough out, a tiny alteration in trajectory is all that's needed. But, we best start now to figure that out, and that's what is happening as it's not an matter of if, but when, we are on directly collision course with something that will wipe us out. Meanwhile, people give a damn about useless nonsense, sports scores, etc, and clueless about that, likely didn't even know about this impressive mission.

True. And I've tried to take that into account in my thought experiment. It really would have to be a very long off, with sufficient warning for us to prepare a mission, launch that mission, and then subsequently intercept the object far enough away to sufficiently alter its path. It will be closing ground the whole time we're moving to intercept, narrowing our window of possible success constantly. Like I said in my other post, perhaps I simply lack imagination, but I think in order for us to do so with enough mass to make a difference seems like the longest of long shots. I may be mistaken, and even if I'm not, it doesn't mean we don't try, no?

**kaiservontexas** · 09-27-22, 10:53

Yes distance is key to a successful trajectory change of the object. Still if that is done it does not take much to change it. Simply changing the brightness and reflectivity of one side over the other is enough to alter orbital tracks. Stick a solar sail on it and watch it leave the system for good. Better yet capture the object and stick it in a following parking orbit of earth for ease of grabbing it later on for the purposes of mining it.

**markm** · 09-27-22, 11:14

This is a classic head fake story. Not sure if it's real on not... nor do I care. But we need to stay on the primary distraction. Being mad about abortion.

**SteyrAUG** · 09-28-22, 01:15

Originally Posted by georgeib

I think maybe I lack imagination, because although I see this as a very cool proof of concept academic exercise, I don't see this ever practically working. Any asteroid or comet of sufficient mass to pose a threat to life on Earth, will not be dissuaded so easily. I'm not a physicist, but I do know how to do basic math, and it seems to me that the amount of mass or force necessary to significantly alter a massive object's path is going to be much more than we can muster.

In my mind, it's not that we are limited by current technology, per se, rather that the laws of physics and our ability to bring enough mass to bear are the limiting factors. I can't help but compare us to a moth trying to alter the trajectory of a fully loaded 18 wheeler traveling at 100 mph by smashing itself into the windshield. In theory, that moth's mass DID alter that truck's trajectory, but in reality it may as well not have for all the difference it would make.

The big take away from the video seems to be that they can actually hit the asteroid at all. In itself an amazing accomplishment. Very cool.

They will need to incorporate a payload to even begin to address threats, this was just a dry run.

Right now the biggest known risk is 99942 Apophis which in 2006 was seen as possibly on target for a direct impact on April 13, 2036 and yes that is a Friday. It has since been revised and there was an earlier date of concern for April 13, 2029 which is not currently believed to be a threat but this one could easily be a problem in the immediate future even though a direct impact has been ruled out by the JPL.

We have had more than a few close ones that passed within half the distance to the moon, thankfully most of them have been pretty small compared to the ones we worry about. Asteroid 2012 DA14 flew by very close in 2013.

**rero360** · 09-27-22, 23:34

Originally Posted by kaiservontexas

Yes distance is key to a successful trajectory change of the object. Still if that is done it does not take much to change it. Simply changing the brightness and reflectivity of one side over the other is enough to alter orbital tracks. Stick a solar sail on it and watch it leave the system for good. Better yet capture the object and stick it in a following parking orbit of earth for ease of grabbing it later on for the purposes of mining it.

Attaching a small ion drive to it would also work given enough time.

**kaiservontexas** · 09-28-22, 09:53

Originally Posted by rero360

Attaching a small ion drive to it would also work given enough time.

Exactly many methods of dealing with such things, if we pay proper attention. I am for capturing all neos (near earth objects) and making them follow the earth for future capture and mining. That is if we want to be forward thinking.