Deep Impact's Dead Horse Lives On

[Saiph]

Never said I disagreed with you. Merely that you need to support your claims (which you've begun to do in this post).<br /><br />You also need to look at what others are posting: Yevaud has even outright said it's a lot of dirt, and it may be a snowy dirt-ball, not a dirty snow-ball.<br /><br />The major disagreement I have is: We see lots of dust, but that could very well be surface dust only. Anybody have info on how solid the material under that is? Afterall, the moon is covered in several inches, to several feet, of fine powdered dust, but is quite solid under that. Maybe the impact threw up a lot of the easily dislodged surface dust, but didn't really mess with (or the dust obscured) the more compact "bedrock" of the surface. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[bonzelite]

i believe Yev refuted even the snowy dirtball, but i can give him that. i think that is what it really is, by the way. <br /><br />please hear that i have never claimed to refute the existence of H20. there is data for that. and it is there. and i have provided links and excerpts in prior threads. <br /><br />i can allow for bedrock. sure. that may be there. as well as ice pockets. yet this does not make it a snowball. that is all i am saying. and while i'm on the subject, i want to thank you, Saiph, for your level-headedness to this debate. i value that and mean it genuinely. your input is often well-informed and brings the polarized bickering down to at least a dull roar. <br /><br />

 

[yevaud]

Density.<br /><br />I have to look at the overall density, regardless (although not exclusive of) the emissions detected. Why is the overall density of the body so low, unless it's a porous icy mixture? Dust aplenty, sure - there's no preferential moment when a comet can accrete dust - but H2O overall.<br /><br />And yeah, just as Regolith on Luna has collected, sure a comet can do the same over millenia and GY. Until it's a "dark body" just as we see. In fact, I'd expect it. Which alters it's overall composition hardly at all. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[bonzelite]

well, maybe the comet is like pumice or something super light like that. like puffed air snacks made of dirt and microfine ice crystals. yummy. "comet bites."

 

[yevaud]

<i>"comet bites." </i><br /><br />A nutritionally balanced, primordial snack... <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[bonzelite]

there ya go. with sparkly trails as you walk around. <br /><br />i think we've come to some semblance of agreement <img src="/images/icons/wink.gif" /> let's wait for Rosetta.

 

[Saiph]

ahhh...forgot that detail.<br /><br />A density near to that of ice (especially for an object so large) does indeed indicate large quantities of ice in the comet, far exceeding organics (carbon molecules, not "life"), or metallics. Why? Cause a large amount of those would shift the density away from that of ice.<br /><br />The only other way to get a near ice density is to be made of something else like ice (similar atomic weight to volume properties)...and we see no evidence for such a compound.<br /><br />So yeah, now I'm tipped towards lots of ice, under a very weathered and dusty surface. Makes sense that lots of water wouldn't be on the surface. There it's exposed to temperature gradients and abrasion that will, over time, remove it. Only the material a little further down, insulated and protected by the dusty surface, would remain intact. <br /><br />but a porous rock, or mixed in granulated rocky material are present.<br /><br />I guess the question now is: How much ice, how much rock, how porous/granulated, and how "hollow ("air" pockets). But I don't think we've got the info available to deduce any of that. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[bonzelite]

^^^ i largely agree on these points. and i will then say that we don't really know what a comet is. that is really the only fact. what has come as data only raises more questions and confuses the picture.

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>let's wait for Rosetta<p><hr /></p></p></blockquote><br /><br />Rosetta! *jumps up and down in excitement* I just wish we didn't have to wait so long. It's like MESSENGER: because it has to basically match orbits and stationkeep with the comet, it has a lot of trajectory correction to do. Alas, that means it will be slow. But oh, what a wonderful mission! For those who don't know, Rosetta will be accompanying a comet throughout its perihelion. If all goes well, it should get to observe the formation of the coma and tail, watch it grow, and then watch it decline again as the comet recedes from the Sun. This will provide unprecedented observations of this process, which will allow planetary scientists to really start to narrow down their theories as to how it all happens. It's going to be very important -- probably more so than Deep Impact. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>