Comet deflection lessons from deep impact.

[igorsboss]

One of the main primary conclusions of the Deep Impact mission is that Comet Tempel 1 is composed primarily as dust, at least down to tens of meters.<br /><br />Suppose we needed to deflect a different comet, one which appears to be identical to Tempel 1, to prevent a terrestrial encounter.<br /><br />Given Deep Impacts's conclusion, what is the optimal deflection method?<br /><br />What would be the effectiveness of nuking the comet?<br /><br />Can the dust be used as fuel in a mass-driver thruster? What would that look like?

 

[vogon13]

A change in the reflectivity of the object (dust 1/2 with titanium dioxide) if done soon enough, will allow radiation pressure from sunlight (and possibly jetting from the nucleus) enough time to deflect the object just enough to either cause it to miss a collision, or to affect a collision, should one be desired.<br /><br />Probably pretty tricky to set up though. Also requires planning ahead, something humans have trouble with from time to time.<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[vogon13]

Nuking would be interesting too. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[yurkin]

Nuking it would be a disaster. The sandbag like composition of it means it can easily absorb a hit without breaking apart or changing direction. Even if you did hit it hard enough to destroy it the collective gravity of all the little particles would enable the comet to reform. <br />It would just make the comet angry.

 

[igorsboss]

Could we accelerate some of the surface dust away from the comet using some kind of mass driver?<br /><br />Could we build some kind of nuclear-powered dust thrower?<br /><br />Could we build an ion drive which ejects ionized dust?<br /><br />Could we heat the dust in a long tube, so that it shoots out the end?<br /><br />Could we put a big bunch of dust in a big strong gun barrel with a tiny nuke at the bottom?

 

[steve82]

Nuking might be an excellent idea. Instead of trying to hit it head on with a nuke, use a directed shaped nuclear charge at some distance away from the comet to heat the dust such that it escapes with enough velocity to provide thrust. Launch your charges cyclically. It could be the first practical use of the Orion concept.

 

[nexium]

Illuminate a small spot centered on the comet with a powerful laser beam over a long distance. The dust would be hot enough to release volitiles from the dust. Dust would be expelled from the shallow creater propelling the comet in the direction that the laser beam points. As the comet rotates, start new crators with the laser beam for as long as the laser assembly was within range of the comet. A few million laser assemblies in solar orbit would protect Earth in 99% of the senarios, from both comets and asteroids (assuming early detection of the possible impact on Earth). Neil

 

[askold]

I wouldn't worry about a comet hitting Earth - that's about as likely as a category 4 hurricane hitting New Orleans ...

 

[igorsboss]

Ok, perhaps I haven't made my point clear, because I'm just hearing the same old deflection ideas again and again, without any reference to the lessons from deep impact.<br /><br />Deep impact says: the comet has a very deep dust layer.<br /><br />The point of this thread is to explore questions like this:<br />How does deep dust change the deflection strategy?<br /><br />How can we use the dusty surface to our advantage?<br /><br />Which deflection ideas would fail to deflect a ball of dust?

 

[vogon13]

A high yield microwave enhanced nuke charge (they are real) might be tuned to a wavelength that penetrates the dust and then is absorbed by the underlying materials.<br /><br />Heating them.<br /><br />Drastically.<br /><br /><br />Sudden and intense vaporization of the lower layers would entrail the dust as it blew off, the reaction forces would be spread over one hemisphere (assuming a fairly spherical nucleus) and you would impart a sizable reaction force to the remainder, hopefully without disrupting it.<br /><br /><br /><br />How's that?<br /><br /><br /><img src="/images/icons/wink.gif" /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[igorsboss]

MUCH better!

 

[vogon13]

It would take a hellish nuke to do this.<br /><br /><br />Anyone up to the challenge?<br /><br />Spacester, Grok and I will evaluate the entries. Extra points if you can make the initial fireball form a smiley face.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>