CompuServe Thread

Comets creating oceans

4 messages in this thread
#125343From: Robert EvansMar 21, 1994 11:24 PM
To all of you out there, Hi, my name is Shannon Evans. I'm working on a science project and need some information on this question. Could comets have created the oceans? I have not had much research on this subject but I was hoping this would help because maybe one of you have gone over this. I have found a book called "RAINBOWS, curve balls" but it does not give enough information. If there is anyone out there who could help me out or has any ideas on this question please contact me.
#125461From: SyndesisMar 22, 1994 6:07 PM
The oceans are very large, obviously. It would have taken a lot of comets to create the oceans. To test whether this hypothesis is correct, you might need to explain why at some point in Earth's history did so many comets fall, and why they've stopped filling the oceans in more recent times. I'm sure your local library can find references to articles on this topic.
#125479From: Todd FrankMar 22, 1994 8:20 PM
I don't know for sure but I had a professor who stated a theory that Iceland was created by either an impact of a comet or meteor on the spreading center that Iceland is located on
#125501From: Doug MitchellMar 22, 1994 11:17 PM
Hi, Shannon– Welcome to the forum! I can easily imagine comets contributing to the oceans, though water released by vulcanism could easily be sufficient to explain the oceans without help from comets. The rocks that form the earth have a certain amount of water built into them, which over eons gets released by volcanoes and such. One theory of the formation of the planets has it that the original cloud of gas and dust (the solar nebula) condensed into small rocks (called "planetesimals", which collided and formed larger rocks, which built still larger ones, and so on until they built up to planets. At one stage, those planetesimals must have been a lot like comets (the comets may be leftovers from this stage?). Thus one might say the earth formed from comets, at least in some sense, from which it follows that the water of crystallization in the rocks came from that source also. Perhaps one can assess the amount of water contributed to the oceans by later-arriving comets by comparing isotopic ratios (which isotopes of which elements? I am not sure, but there are only so many isotopes of oxygen and hydrogen to look at) in the ocean, in deep rocks, and in comets, to whatever extent these things are known. –Doug