<div>I just watched a program on this the other day, fascinating stuff.  Another idea they mentioned (providing we had enough time), was parking a craft near the object, to alter it's velocity (by a relatively minuscule amount) thus changing it's trajectory to a 'safe' one.</div>

<div>I hope the nuke option truly is the LAST option.  </div><br>On Fri, May 13, 2011 at 8:55 AM, Anders Sandberg <span dir="ltr"><<a href="mailto:anders@aleph.se">anders@aleph.se</a>></span> wrote:<br><div class="gmail_quote">

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">and they are in orbits that are safe for at least the next century.</blockquote></div><br><div>Provided no currently unknown variables don't lead to altered trajectory?  Certainly some object we don't know about could come by and change things?</div>

<div><br></div><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">

<span class="Apple-style-span" style="border-collapse: collapse; font-family: arial, sans-serif; font-size: 13px; ">Mark Boslough showed that some of them might produce pretty destructive airbursts.</span></blockquote><div>

<br></div><div><a href="http://en.wikipedia.org/wiki/Tunguska_event">http://en.wikipedia.org/wiki/Tunguska_event</a> gave us a taste.</div><div><br></div><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">

<span class="Apple-style-span" style="font-family: sans-serif; font-size: 13px; line-height: 19px; ">with 10–15 megatons of TNT (42–63 PJ) the most likely<sup id="cite_ref-shoe_6-1" class="reference" style="line-height: 1em; font-weight: normal; font-style: normal; "><a href="http://en.wikipedia.org/wiki/Tunguska_event#cite_note-shoe-6" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; white-space: nowrap; background-position: initial initial; background-repeat: initial initial; "><span>[</span>7<span>]</span></a></sup>—roughly equal to the United States' <a href="http://en.wikipedia.org/wiki/Castle_Bravo" title="Castle Bravo" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; background-position: initial initial; background-repeat: initial initial; ">Castle Bravo</a> thermonuclear bomb tested on March 1, 1954, about 1,000 times more powerful than <a href="http://en.wikipedia.org/wiki/Little_Boy" title="Little Boy" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; background-position: initial initial; background-repeat: initial initial; ">the atomic bomb</a> <a href="http://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki" title="Atomic bombings of Hiroshima and Nagasaki" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; background-position: initial initial; background-repeat: initial initial; ">dropped on Hiroshima</a>, Japan, and about one-third the power of the <a href="http://en.wikipedia.org/wiki/Tsar_Bomba" title="Tsar Bomba" style="text-decoration: none; color: rgb(6, 69, 173); background-image: none; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: initial; background-position: initial initial; background-repeat: initial initial; ">Tsar Bomba</a>, the largest nuclear weapon ever detonated.</span> </blockquote>

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