"Super Comet: After the Impact" -- What did you think?

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>I could be wrong here, but I don't think inter-planetary space has enough of a medium for the warhead to create a powerful concussive shockwave to bleed off a significant enough amount of energy of an asteroid that is cruising through space at 30+ km per hour.<p><hr /></p></p></blockquote><br />Forget the shockwave. You hit it with the radiation. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

As I already noted, good luck computing the impact angle in time. You would need to have your mission strike out near Jupiter -- possibly multiple orbits ahead of time. You might not know the impact angle until just days before the impact. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>burn up in the atmosphere<p><hr /></p></p></blockquote><br />I hate to tell you this, but if all you do is break up the impactor, sure, you might burn it up. However, you will impact a <font color="yellow"><b>lot</b></font>of heat to the atmosphere. You would make global warming way worse. You would also add a lot of dust.<br /><br />The good news? Such a break up would decrease the overall mass hitting us by spreading it out. The bad news associate with that? You would also make it <font color="yellow">more</font>likely that SOMETHING would hit. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

If you really want to look at the crater, we would need to look at it in the outer solar system. That would allow us to skip the coma. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[MeteorWayne]

The coma is not thick enough to obscure the surface if it's a close pass.<br />THe Deep Impact Impact took place 1 day after perihelion at about 1.5 AU from the sun, and we didn't have any problem seeing it then. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[3488]

Hi MeteorWayne.<br /><br />That was what I thought. Deep Impact got a beautifully clear view of the nucleus.<br /><br />Fantastic mission, with a fantastic extension.<br /><br />Well done to all involved.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[willpittenger]

Update: I just watched a show on National Geographic called <i>Ancient Asteroid</i>. They state that an asteroid that is weak enough to break up in the atmosphere would be worse than a straight impact from the same amount of mass. They also state that attempts to "destroy" the asteroid before impact would be worse than not bothering. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[3488]

Hi willpittenger.<br /><br />That is only partly true.<br /><br />Not all asteroids are rubble piles held together by gravity.<br /><br />Some such as 253 Mathilde & 25143 Itokawa are, of that type.<br /><br />Others such as 243 Ida, 433 Eros & 951 Gaspra, are not. They are solid coherent bodies.<br /><br />The last three are far too dense, to be rubble piles. They are genuine planetesimals.<br /><br />So if a potential impactor is like 25143 Itokawa, than yes, your last statement is likely to <br />be true.<br /><br />If a potential impactor is like 951 Gaspra, than no. That asteroid will not disrupt until it is<br />destroyed upon impact.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[nexium]

Scattering the rubble pile is sort of like shotgun versus rifle for shooting flying birds The bullet = asteriod might miss even if it is projected for a direct hit plus or minus 4010 miles. If the rubble pile spreads to a diameter of 4011 miles then some or most, or all of it will hit somewhere on Earth. If the rubble pile spreads to 10,000 miles, then some of it will hit Earth, but more than half (80%?) of the mass will miss Earth.<br />If enough peices burn up in the atmosphere to warm Earth's whole atmosphere an average of 5 degrees c = 9 degrees f for a few hours, the giant rubble asteroid or comet would only be partially scattered even with a 100 megaton blast. The black dust, however, might cause global warming = doesn't everything according to the global warming advocates? Neil

 

[3488]

That is very true Neil.<br /><br />There are far too many variables.<br /><br />Also a silicate rich asteroid like 951 Gaspra, may behave very differently to a Carbonaceous rich<br />one like 253 Mathilde or a metallic one like 27 Lutetia???<br /><br />Just nuking them with ICBMs anyhow is more tantamount to Hollywood <br />films IMO.<br /><br />Changing their orbits howver may seem plausible, but we are talking of billions & billions, <br />if not trillions of tons of mass.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[alokmohan]

Killer Collision: Dino demise traces to asteroid-family breakup<br />Ron Cowen<br /><br />A huge chunk of rock hit Earth 65 million years ago, setting off events that wiped out the dinosaurs. That chunk, astronomers now say, was a wayward fragment from a collision between two giant asteroids in the inner part of the asteroid belt, which lies between Mars and Jupiter. The new study adds to the evidence that both Earth and moon have been bombarded by about twice the usual number of asteroid fragments during the past 200 million years. <br /><br /><br /> <br />KILLER ROCK. Artist's illustration shows collision of two giant asteroids (left). Ejected fragments might have struck the moon and Earth, creating the lunar Tycho crater (top right) and triggering widespread destruction on Earth some 65 million years ago (bottom right).<br />SwRI<br /> <br /><br /><br />Earth is now at the tail end of this asteroid shower, say Bill Bottke of the Southwest Research Institute in Boulder, Colo., and his colleagues in the Sept. 6 Nature. <br /><br />The researchers began their study by pondering the pattern of craters on 951 Gaspra, a member of the Flora family of asteroids. Searching for objects that could have caused the impacts, the team examined a much darker, harder-to-detect group of asteroids, the Baptistina family, that resides close to the belt's inner edge and near the Flora family. <br /><br />Bottke and his colleagues were intrigued to find that the Baptistina family stretches over a region containing two gravitational-escape hatches, places where a gentle nudge could kick an asteroid out of the belt and into the inner solar system toward Earth. Once ejected, members of the Baptistina family could wallop a lot more objects than just Gaspra. <br /><br />Tracing the paths of the Baptistina asteroids back in time, the researchers calculate that the objects orihttp://www.sciencenews.org/articles/20070908/fob3.asp<</safety_wrapper>

 

[dan_h]

This might all be a bit more relevant than one would like to believe...<br /><br />http://news.bbc.co.uk/1/hi/uk/3200019.stm<br /><br />(though probably not)

 

[MeteorWayne]

That information is quite out of date. It was from 2003.<br /><br />2003 QQ47 isn't even in the top 140 on the impact risk. <br /><br />Welcome to Space.com! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[dan_h]

Whoops, that's the wrong link. These comets all look a like from a distance <img src="/images/icons/wink.gif" /><br /><br />Jodrell Bank recently reported a possible near miss (this year some time) but I can't find a link. However I did notice when it was on the telly that a "near miss" was categorised as a probability of 0.25 of it passing within 500,000 km of Earth which seemed small to me.

 

[MeteorWayne]

Perhaps it's 2007 RU9 <br /><br />Just discovered, and fairly high risk. Of course, risk is often very high shortly after discovery until more observations refine the orbit.<br /><br />It's a 1/4 km object in an orbit that comes near earth in early March.<br /><br />However, it's orbit is poorly known at this time, so let things settle a few days. It was only discovered 2 days ago and the orbit errors are very large.<br /><br />Of course I just realized you said Jodrell Bank announced it, so that probably would not have been a visual observation.<br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[MeteorWayne]

Well 500,000 is further than the moon (~384,000 km) but spacewise, that is a close approach <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[nexium]

1/4 kilometer is large enough to total a large city, but damage 100 kilometers from impact would be mostly rare and minor, in most senarios. Neil

 

[MeteorWayne]

That's correct.<br />You wouldn't want to be 25 km away though <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[willpittenger]

Maybe it would be nice enough to take out Bin Laden and the Taliban leadership for us. <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[the_id]

A comet/asteroid hitting Tora Bora and taking out bin Laden & Co.? Damn! What a propaganda boon that would be for Christianity!<br /><br />Anyways…<br /><br />I suspect that if a rock were coming (with enough mass to “Chicxulub†this place again), trying to stop, destroy or deflect it would be more or less beyond our capacity just now. Our best plan would be to put all our efforts into getting a sizable and viable gene pool off-world to perhaps colonize there or at least return some time after the fact and begin rebuilding.<br /><br />Those of us not lucky enough to go along could focus on learning how to chip a Clovis point--just my thoughts.<br />

 

[astroguard]

Neil wrote about Asteroid 2007 RU9:<br /> <i># 1/4 kilometer is large enough to total a large city, but damage<br /> # 100 kilometers from impact would be mostly rare and minor</i><br /> <br />Negative, Neil: with an impact energy of 790 megatons TNT, we would expect third-degree radiation burns out to 180 kilometers radius, based upon the calculations in "The Effects of Nuclear Weapons" (Glasstone and Dolan).

 

[MeteorWayne]

Actually I played around with this:<br />http://www.lpl.arizona.edu/impacteffects/<br />And he is indeed correct, the impact effects would be minimal at 100 km.<br />You certainly would notice it though! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[nexium]

Perhaps both results are correct. If the asteroid impacts at 50 kilometers per second instead 15 kilometers per second and breaks up at high altitude, lots of far ultra violet radiation is produced, instead of infra red, and the fire ball is above the horizon even at 180 kilometers, so bare skin could get charred. Neil

 

[MeteorWayne]

However that is not the case for this asteroid. Impact velocity (pre gravitational acceleration) is 16.21 km.sec for a 19.1 km/sec atmospheric impact speed. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[pyoko]

"1/4 kilometer is large enough to total a large city, but damage 100 kilometers from impact would be mostly rare and minor, in most senarios. Neil"<br /><br />I'm sorry, but you CANNOT be serious... 1/4 km traveling at a thousand km/s would most likely total MUCH more than a large city. <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>