Nasa chief Charles Bolden's advice on asteroid

[FBM]

They've been proposed for providing thrust (?) to spacecraft, so given enough time I imagine they could alter the path of an asteroid. But I think it would take a long time. We'd need to know about the incoming rock well in advance.

If an asteroid is a million times more massive than a spacecraft (which, for a dangerous one, will be a minimal figure), it will take a million times longer to alter its velocity, given the same area of light sail...

An ion engine, landed on the asteroid, and using the asteroids substance as reaction mass is a much more realistic solution...

Ah...right. It would have to be pretty massive just to warrant the attention in the first place, eh? OK, scrap the solar sail. A genuine thrust engine landed on the rock seems all but required. Now if I could just get them to let me fly it...

[Gawdzilla Sama]

They've been proposed for providing thrust (?) to spacecraft, so given enough time I imagine they could alter the path of an asteroid. But I think it would take a long time. We'd need to know about the incoming rock well in advance.

If an asteroid is a million times more massive than a spacecraft (which, for a dangerous one, will be a minimal figure), it will take a million times longer to alter its velocity, given the same area of light sail...

An ion engine, landed on the asteroid, and using the asteroids substance as reaction mass is a much more realistic solution...

Ah...right. It would have to be pretty massive just to warrant the attention in the first place, eh? OK, scrap the solar sail. A genuine thrust engine landed on the rock seems all but required. Now if I could just get them to let me fly it...

Flaw in that argument is that you need smaller and smaller changes the farther away it is. Alter it 1/1,000th of a mile at 1,000,000,000 miles and it's a miss.

[FBM]

Shit. I'm not going to change my mind again, dammit.

[Gawdzilla Sama]

Ayaan just reminded me of one plan, put a large mass near the problem and let gravity alter its course. Again, you need time for this to work.

[Jason]

L8. Also putting a mass large enough to alter the course of the asteroid and far enough out is beyond our technological capabilities.. and probably will be for some time.

[Gawdzilla Sama]

Wrong.

[cronus]

L8. Also putting a mass large enough to alter the course of the asteroid and far enough out is beyond our technological capabilities.. and probably will be for some time.

Necessity is the mother of invention. I bet there'd be a jolly good go at shifting a rock if it was heading this way with any degree of certainty and size?

[Gawdzilla Sama]

Send up a few ion engines, attach them to a smaller rock and move it near the big one. SIMPLES.

[Ayaan]

I think the biggest problem would be detecting in time for this to work. Anything we send up wouldn't have to be complicated. All it would have to be able to do is fly to the asteriod and then travel next to it at a given distance from it - like manmade satellites do now.

[cronus]

I think the biggest problem would be detecting in time for this to work. Anything we send up wouldn't have to be complicated. All it would have to be able to do is fly to the asteriod and then travel next to it at a given distance from it - like manmade satellites do now.

Every year sensitivity increases, all it takes is a change of resource focus away from war on earth and towards defense from above...and that is political. Twentieth century 'nationalist' politicians need replacing with twenty first century 'globalist' ones....and the difference is small but crucial.

[Blind groper]

Flaw in that argument is that you need smaller and smaller changes the farther away it is. Alter it 1/1,000th of a mile at 1,000,000,000 miles and it's a miss.

I doubt the mirror idea would work.
It would need unbelievably precise aiming. It would have to focus on a lump of rock many billions of kms away, and focus on one off center spot on that rock, and hold it there exactly for months. The aiming would have to be by dead reckoning, since, even with a telescope bigger than any in existence today, it would still take 20 minutes for any correction to be implemented and seen to be implemented, to give feed-back, due to speed of light limits.

Sorry. I just do not see that being possible any time in the foreseeable future.

Another point.

The asteroid is almost certainly tumbling as it flies through space. That would almost certainly prevent any mirror heating of one spot to use that to divert its orbit. If an ion drive machine was on the asteroid, the computer controlling it could deliver precise 'puffs' of reaction mass as it tumbles to keep the sideways push always in the same direction.

[Gawdzilla Sama]

They aimed Hubble at a spot in space for 100 friggin' hours.

And, you're right, if it's tumbling it wouldn't be heated the same way. But by hitting it at the right time you could cause inertia to help you divert it. And, of course, any lateral energy is going to shove it sideways.

[Gawdzilla Sama]

http://news.discovery.com/space/asteroi ... 130130.htm

[FBM]

Ayaan just reminded me of one plan, put a large mass near the problem and let gravity alter its course. Again, you need time for this to work.

[Gawdzilla Sama]

Ayaan just reminded me of one plan, put a large mass near the problem and let gravity alter its course. Again, you need time for this to work.

What a novel concept.

No.