As many of you may or may not know, the leading theory on how the Moon formed is through a collision between a Mars sized world, often dubbed Theia, and the early Earth. Two spacecraft, STEREO, are going to be deployed to the L-5 and there is hope that they will find remnants there of the collision. Both the Universe Today and Centauri Dreams have articles.
Personally I think this is Hogwash.
ReplyDeleteI have seen many reports of this and not one of them has suggested how floating debris in space could re form to make a planetoid. This just doesn't happen or we would have seen it happening already as we scan the galaxy's with our telescopes. Also, unless the variables for exact time and position in space, orbit and trajectory were knows for "Theia" and the Earth at the time of the so called collision (which they are not) there is no way possibly NASA or anyone else, could know where to look for it in present time much less find it an study it.
I believe this is just another ploy of NASA ( like they did a lot of in the late 1960's) to try to keep public opinion on their side so they could get more money from Congress.
John,
ReplyDeleteI am uncertain whether or not to take your comment seriously. Are you aware of the current theories of how planets form?
Of course I am. but that's just all they are... theories. Having a theory even a popular and generally excepted one, does not make it true. I will give you an example.
ReplyDeleteJust a very short while ago as time goes, most of the world believed the Earth was flat. They believed this with with all of their heart from their intellect and observations (and this is the kicker) at the time. Of course as knowledge grew we learned that the earth was round.
Look at how many things have changes in the last 100 years. In the next 100,things will change that much more.
What we have today are theories. I believe what I said holds true, and until we have actual proof, theories are all they will be.
I believe there is way too much data that is missing simply because we couldn't be there at the time to collect it properly, and due to this lack of data we can never be certain just how good our theories are.
Also, I believe a planet forming from initial origins and a planet forming from the remnants of two already formed and cooled planets hitting together are two different things altogether.
Also, I believe a planet forming from initial origins and a planet forming from the remnants of two already formed and cooled planets hitting together are two different things altogether.that's just it: there's not much difference. The stages that the planets go through often have planetesimals crashing into each other and they are not molten bits of rock. Nor were they largely gas.
ReplyDeleteBesides, an impact like that is going to release vast amounts of heat...which will vaporize and melt giga/tera/peta/exatons of rock...
Your argument sounds a lot like "they already existed, so they can't change." When combined with the 'it's only a theory' bit then its a little troublesome. I could be misreading that completely.
How do YOU think the moon formed?
How do I think the Moon was formed?
ReplyDeleteThis goes back to the missing data. I do not know how the Moon was formed but here are some of the reasons I have problems with this theory:
There is a Law ( I forget who's ) that says every time two objects collide you will have something from each rub off on the other. Earth rocks and Moon rocks are so different, if the moon formed from material that was once part of the Earth and another body we would expect to find Earth like rock on the Moon and Moon like rock on the earth (fron this other body (Theia). This is not the case. Of course we would find rock material from Theia in both places too, and who knows what Theia rocks were like. As I am just a lay person, a more detailed scientific way of explanation follows:
Ratios of the Moon's volatile elements are not consistent with the giant impact hypothesis.
There is no evidence that the Earth ever had a magma ocean (an implied result of the giant impact hypothesis), and it is likely there exists material which has never been processed by a magma ocean.
Iron oxide (FeO) content of 13% of the bulk Moon properties rule out the derivation of the proto-lunar material from any but a small fraction of Earth's mantle.
If the bulk of the proto-lunar material had come from the impactor, the Moon should be enriched in siderophilic elements, when it is actually deficient of those.
Of course If I were to answer your question with a theory it would have holes in it too because of the missing data. Therefore I believe that this is one question we may never know the answer to. We may never have enough data to make a theory that accounts for every possible flaw in the each theory.
Yes there have been similarities between the Earths mantle and the surface of the Moon, but for me this is not a smoking gun. I suspect you would find similar similarities on many other planets also.
You state:
ReplyDelete"Besides, an impact like that is going to release vast amounts of heat...which will vaporize and melt giga/tera/peta/exatons of rock..."
This would lead me to believe that after our planet cooled it was hit by this object Theia, the Earth either was turned back into a molten state and thus absorbed all the particulate matter from Theia as it re-cooled or that there should be a whole region on earth (impact site) with rock material made up of a combination of earth and Theia, (which I suspect would resemble moon rock) an have formed a type or rock found no other place on earth.
I just don't see it.
Although, To be fair, (as any hypothesis or theory goes) any and all geological data we have from the earth may be flawed. It is postulated (again another theory.. I know..I will try not to make circular arguments) the earth has been remade many times over,that due to cataclysmic events such as the utter devastation and reforming of the Earth's crust due to polar shifts and other phenomena; what we have is new data since the last cataclysm and therefore may not be trusted. .That being said if that were the case, it would be possible for the Earth to have had more evidence of a Theia collision in the distant past.
ReplyDeleteTo corroborate your post further I would like to offer this rebuttal to those who disparage the idea without any research let alone geological knowledge.
ReplyDeleteHere is some proof that an Earth-Theia impact is a likely theory: the moon is moving away from Earth at 3.8cm/a, putting it pretty much within our atmosphere 4.53ba (original Earth formation 4.55-4.56ba). Also anorthosite is a mineral that is found on both earth and the moon, after all a sandstone conglomerate looks nothing like quartz.
For a more indepth look at the theory try The Earth For Physicists.
I’ll try to summarise the paper here:
Theia was slightly smaller than mars with possibly its own moon. It slipped out of orbit for a few reasons due to the gravitational pull at one of the larange points. With a glancing blow that would have had half the earth red hot within 50 minutes, the heavy inner core of Theia sunk into Earths core. This increased our gravity substantially more than a normal Earth sized planet, meaning we didn’t suffer the same loss of atmosphere that Mars did. Most of the lighter materials of Theia vaporised on impact however a ring of debris would have been present gradually forming the Moon.
Just on a further note the two STEREO satellites mentioned are currently obtaining 3D mapping of the sun, so while they are conveniently at the Larange points 4 and 5, we will be able to have a look there for Theia remnants. These are more likely to be found and seen in these gravity wells; if you want to see if you can spot any, just join the Larange Campaign.
Hi Will. I'm Rufino Herrera, from Spain, and the autor of the illustration. Could you link the original image to my account on flickr?
ReplyDeletehttp://www.flickr.com/photos/rufo_83/313822473/
Thanks, and congratulations for the blog.
There is a lot of evidence that in our moon are bases, alien bases, alien beings, alien ships, according to the Apollo 11 pictures and summaries, they witnessed all that, now the theory that the moon was brought here from another part of the galaxy looks more and more viable.
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