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Moon was produced by head-on collision?
Moon was produced by head-on collision | Astronomy.com
http://www.astronomy.com/news/2016/0...d-on-collision The Theia Theory used to talk about a glancing blow between the early Earth and a Mars-sized Theia, perhaps at 45 degrees. New data suggests that Theia might have actually hit head-on with the Earth. That's because the percentage of Oxygen 16/17/18 isotopes between the Earth and Moon are nearly identical, indicating that they came from the same source. My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. Yousuf Khan |
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Moon was produced by head-on collision?
On 1/30/16 6:55 PM, Yousuf Khan wrote:
Moon was produced by head-on collision | Astronomy.com http://www.astronomy.com/news/2016/0...d-on-collision The Theia Theory used to talk about a glancing blow between the early Earth and a Mars-sized Theia, perhaps at 45 degrees. New data suggests that Theia might have actually hit head-on with the Earth. That's because the percentage of Oxygen 16/17/18 isotopes between the Earth and Moon are nearly identical, indicating that they came from the same source. My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. Yousuf Khan Thanks for Posting this. -- sci.physics is an unmoderated newsgroup dedicated to the discussion of physics, news from the physics community, and physics-related social issues. |
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Moon was produced by head-on collision?
Dear Yousuf Khan:
On Saturday, January 30, 2016 at 5:55:31 PM UTC-7, Yousuf Khan wrote: .... My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. How many of them involved collision-and-mergence of two bodies? The only variant I am aware of that is significantly different, is gravitational capture, and that took a third body. Still have an initial Theia... David A. Smith |
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Moon was produced by head-on collision?
Yousuf Khan wrote:
Moon was produced by head-on collision | Astronomy.com http://www.astronomy.com/news/2016/0...d-on-collision The Theia Theory used to talk about a glancing blow between the early Earth and a Mars-sized Theia, perhaps at 45 degrees. New data suggests that Theia might have actually hit head-on with the Earth. That's because the percentage of Oxygen 16/17/18 isotopes between the Earth and Moon are nearly identical, indicating that they came from the same source. My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. Yousuf Khan The truth is...the origin of our solar system is...unknown. So, how everthing got put together is unknown...including the moon. --- news://freenews.netfront.net/ - complaints: --- |
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Moon was produced by head-on collision?
Dear Starmaker:
On Sunday, January 31, 2016 at 10:44:33 AM UTC-7, The Starmaker wrote: .... The truth is...the origin of our solar system is...unknown. So, how everthing got put together is unknown... including the moon. Does "unknown" mean "unknowable"? Is all quest for knowledge ultimately doomed to failure? Or are you a post-only nay-sayer? We have brains, and we have data. Do you mind if we use one, and try and understand Nature, while you fiddle away, Nero? David A. Smith |
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Moon was produced by head-on collision?
The Starmaker wrote:
Yousuf Khan wrote: Moon was produced by head-on collision | Astronomy.com http://www.astronomy.com/news/2016/0...d-on-collision The Theia Theory used to talk about a glancing blow between the early Earth and a Mars-sized Theia, perhaps at 45 degrees. New data suggests that Theia might have actually hit head-on with the Earth. That's because the percentage of Oxygen 16/17/18 isotopes between the Earth and Moon are nearly identical, indicating that they came from the same source. My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. Yousuf Khan The truth is...the origin of our solar system is...unknown. So, how everthing got put together is unknown...including the moon. For those seeking to know the origin of our solar system...all one has to do is start and end he 'In the beginning God created the heavens and the earth.' The above sentence contains all the information one needs to understand the origin of our solar system and the universe. Within this sentence contains the entire knowledge of the origin of the universe. 'In the beginning God created the heavens and the earth.' You just need to know how to decode it. For example, ..."created the heavens and the earth", .. "heavens" doesn't necessarly mean stars. It could mean how stars looked before they became stars...without the light. In other words, the earth and the stars were created at the same time, they just both weren't formed completely then. |
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Moon was produced by head-on collision?
On 01/02/2016 2:10 AM, The Starmaker wrote:
The Starmaker wrote: The truth is...the origin of our solar system is...unknown. So, how everthing got put together is unknown...including the moon. For those seeking to know the origin of our solar system...all one has to do is start and end he 'In the beginning God created the heavens and the earth.' The above sentence contains all the information one needs to understand the origin of our solar system and the universe. Yeah, that's the hypothesis we usually start off with initially, and then we invent new instruments and obtain new observations which lead to better hypotheses, and then eventually to some proper theories. Yousuf Khan |
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Moon was produced by head-on collision?
Yousuf Khan wrote:
On 01/02/2016 2:10 AM, The Starmaker wrote: The Starmaker wrote: The truth is...the origin of our solar system is...unknown. So, how everthing got put together is unknown...including the moon. For those seeking to know the origin of our solar system...all one has to do is start and end he 'In the beginning God created the heavens and the earth.' The above sentence contains all the information one needs to understand the origin of our solar system and the universe. Yeah, that's the hypothesis we usually start off with initially, and then we invent new instruments and obtain new observations which lead to better hypotheses, and then eventually to some proper theories. Yousuf Khan Well, it reads "the heavens and the earth", not 'the heavens and then the earth'. So, somewhere along the line...your new instruments, your better hypotheses, and proper theories is off by 5 billion years. --- news://freenews.netfront.net/ - complaints: --- |
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Moon was produced by head-on collision?
In article ,
Yousuf Khan writes: Moon was produced by head-on collision | Astronomy.com http://www.astronomy.com/news/2016/0...d-on-collision The UCLA press release is at http://newsroom.ucla.edu/releases/mo...forming-planet and the article in _Science_ is at http://science.sciencemag.org/content/351/6272/493.full I couldn't find a preprint, but there might be one somewhere. The Theia Theory used to talk about a glancing blow between the early Earth and a Mars-sized Theia, perhaps at 45 degrees. New data suggests that Theia might have actually hit head-on with the Earth. That's because the percentage of Oxygen 16/17/18 isotopes between the Earth and Moon are nearly identical, Specifically, the new data show the isotope ratios (actually a ratio of differences) is the same within 2 ppm. A paper last year http://science.sciencemag.org/content/344/6188/1146 found apparent differences at the 18 ppm level. The new paper suggests that was sample selection, i.e., the rocks analyzed earlier were not characteristic of the whole Moon. indicating that they came from the same source. If the isotope ratios are identical, _either_ Earth and Theia had identical ratios to begin with (possible but not very likely) _or_ the present Earth and Moon have identical fractions of Theia material. That last would require a head-on collision with everything getting mixed; a glancing collision would put a larger fraction of Theia material into the Moon. I'm very much an outsider here, but this looks to me like a highly technical insider dispute that most of us shouldn't worry about. My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, The isotope ratios are _at least_ very similar, now seemingly identical within measurement accuracy. This tends to support the Theia hypothesis. If the Moon formed on its own and was somehow captured by the Earth, it would be expected to have very different isotope ratios. so now that that isotopic evidence has disappeared, why keep the Theia Hypothesis? There were other theories prior to that, which were discarded due to the isotopic evidence. That evidence being the _similarity_ of ratios, which is now stronger than before. The argument now seems to be about the details of the collision, but as I say, I'm an outsider. For a different hypothesis to be viable, it will have to be consistent with not only the isotope ratios but also the element ratios and other evidence. As with all scientific hypotheses, it will have to be testable (falsifiable) to receive scientific consideration. -- Help keep our newsgroup healthy; please don't feed the trolls. Steve Willner Phone 617-495-7123 Cambridge, MA 02138 USA |
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Moon was produced by head-on collision?
On 01/02/2016 5:27 PM, Steve Willner wrote:
In article , Yousuf Khan writes: My question is, if the isotopic evidence which was used to create the Theia Hypothesis in the first place, due to a previously perceived difference in isotopic abundances, The isotope ratios are _at least_ very similar, now seemingly identical within measurement accuracy. This tends to support the Theia hypothesis. If the Moon formed on its own and was somehow captured by the Earth, it would be expected to have very different isotope ratios. The Moon capture hypothesis was only one such hypothesis. That one would still be excluded by this recent finding. Other ones that would still be viable are the Fission hypothesis, where the Moon was once a part of the Earth, but due to an imbalance it pinched itself off of the Earth. This would certainly maintain identical isotope levels between the Earth and Moon. Another one is the Condensation Hypothesis, which suggested that the Earth and Moon formed from the same section of the original solar system nebula. So basically the two worlds evolved together as a twin planet system. This would also pretty much maintain identical isotope levels. This site even says that if the isotope levels are different, then the above theories would be unlikely, but now that the isotope levels are similar, those theories come back into play. Theories of Formation for the Moon http://csep10.phys.utk.edu/astr161/l...formation.html Yousuf Khan |
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