Impactor Ejects Mighty Water Mass

BBC ^ | 4-4-2006 | Jonathan Amos

[mrsmith]

"The question is why the comet continued to eject material for so long after the initial impact. "

It might have stayed kinda warmish in the area where it got about a 20 giga-joule smacking.

[iThinkBig]

"I'm surprised.

But, if true, then we know where we can get water in space."

That indeed would be a big deal. I believe some day we will be able to fully extract energy from hydrogen and propel a space craft. Just pull up to your nearest comet...

[ml/nj]

My geological example had to do with EROSION, which is the process by which soil and rock are REMOVED by water. I honestly don't know where you are getting the "ground rising up" reference.

It's the conventional wisdom in geology. E.g.:

Can rivers run uphill to get across mountains?

There are many locations throughout the western U.S. where rivers have cut canyons through mountain ranges instead of taking easier, lower routes around them. For example, the Wasatch Range near Salt Lake City is of recent origin and is still rising. Yet, rivers such as the Weber, Ogden, and Provo cut right through the range producing canyons thousands of feet deep. We can conclude that the rivers were in place first; and as the mountains rose, the rivers acted as stationary band saws cutting deep groves into the rising block. There are examples where even arroyos have cut canyons through rising blocks. For example, east of Albuquerque, NM, highway I-40 uses Tijeras Canyon cut by Tijeras Arroyo through the Sandia Mountains. This leads to the following important rule. An established river (or stream or even an arroyo) is frequently capable of maintaining its path through a rising mountain range.[Emphasis added}

I found this at http://www.durangobill.com/PaleoriversPart1.html after doing a Google search on Grand/Canyon/formation.

Next time you decide you want to play maybe you could try to inform yourself about what experts believe before you comment. As for Astronomy, it's always been a hobby of mine. I already owned a telescope 50 years ago. I took a couple of college courses when I was a genuine student and have sat in on a couple more as an ersatz student. Unless astronomy is your profession, it is unlikely that you have greater knowledge of the general subject than I do. It is my opinion that each theory in the collection of theories of solar system formation is quite tenuous. (The fact that there are multiple theories is a clue that most/none of them are any good.) As such these theories are not evidence for anything, which was my point.

ML/NJ

[blam]

"It might have stayed kinda warmish in the area where it got about a 20 giga-joule smacking."

They also misjudged the ejecta fron the Shoemaker-Levy comet impact. It was much, much more than expected.

[inquest]

You're right that water can't remain liquid in the vacuum of space. When they refer to water in this article, they almost have to mean the general chemical sense (H₂O molecules).

As for ice being able to remain solid, you'll note that that your information only refers to the boiling point - that is, the conversion from liquid to gas. The conversion from solid to anything else is a separate issue.

It's pretty much true of all substances that the boiling point will decrease as pressure goes down. But that doesn't mean these substances can't exist as solids. They all certainly can. Solids are held together by electrostatic forces between molecules. They generally don't need outside pressure for that. It's a bit different for liquids, because with them, the molecules aren't held in place. Instead, they slip and slide all around each other. So that usually means that some outside force has to hold them together to prevent them from dispersing into a gas.

[inquest]

Really? We observe other solar systems forming?

We've seen accretion disks at other stars. Beta Pictoris is probaby the best-known example, but there are many others.

[ml/nj]

We've seen accretion disks at other stars. Beta Pictoris is probaby the best-known example, but there are many others.<

Good news here, for you and all the others who think they know how the solar system was formed.

(So, what if it's another day old theory?)

ML/NJ

[inquest]

That link dealt specifically with the formation of planets. What your question dealt with is if comets underwent any significant chemical change since their formation. At this point, the question that really should be asked is not if there's any evidence that there hasn't been any significant change, but if there's evidence that there has. As far as I know, there's no evidence to speak of that such changes have occurred. Nor would there be even any proposed mechanism whereby it would happen.

[SunkenCiv]

Note: this topic is from April 6, 2006, iow three years ago.

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