[OT] Light from a distant sun

[Castellan]

Point the first - We do not know the Moon's exact origin. The jury is still out on it. Impact is one theory, but not the only one.

I'd say the jury isn't really "out" on this, anymore. The samples returned from the Apollo missions helped Lunar Geologists come up with a very good theory for the formation of the Moon -- one that far outpaces the other theories.

The Fission Theory suggests that Earth's high rate of rotation caused a "spawining" of the Moon. Unfortunately, while there are similarities between the Earth and the Moon (basaltic rock is very similar, for example) there are also some big differences, especially in terms of minerals unique to the Moon.

The Capture Theory suggests that Earth trapped a wandering neighbor in orbit. If this were true, we'd find a lot more differences between the two bodies than similarities. This just isn't the case. The Moon is similar enough to the Earth that it doesn't seem very likely that the two bodies formed separately.

Finally, we have the Binary Theory. The suggestion here is that Earth and the Moon formed together at the same time and out of the same (or similar) accreting matter. This theory fails the Apollo litmus test, too. Lunar Geologists analyzing rock samples from the Moon discovered that it was much hotter during its "birth" than the Earth was. And, though we've discovered some water on the Moon since the Apollo missions, the samples returned showed no water trapped within them. This is strong evidence for the Moon forming at a different time than the Earth, instead of from the same cloud of material.

Anyway, not many people subscribe to the non-Impact-Theory theories, since it seems pretty reasonable that each of them fails in one area or another, while the Impact Theory doesn't.... yet

Obviously, a better theory could come along someday, but for now, it's a safe bet to stick with the Impact Theory!

 

[Umbran]

Anyway, not many people subscribe to the non-Impact-Theory theories, since it seems pretty reasonable that each of them fails in one area or another, while the Impact Theory doesn't.... yet

Well, the impact theory has it's own plausibility problems. The best versions I know of at the moment require the impacting object to be about the size of the planet Mars! Aside from this being improbable, there's a lot of question as to whether such a huge impact should not have left other telltale signs.

 

[Fayredeth]

Sheeesh...

Well, it looks like I was "drafted" into this conversation, before I even saw it .

Sparticles: Sparticles are the product of the Supersymmetry Theory that helps explain the current structure of the cosmos from the first instants after the Big Bang to now. The theory states that each particle of our "normal" matter has an accompanying sparticle (leptons=sleptons, quarks=squarks, neutrinos=sneutrinos, photons=photinos, W particles=winos, etc.), but the sparticles weigh much more (the most massive is theorized to be about 1000 times more massive than a proton). They have not yet been observed, but they don't occur naturally in nature anymore; they disappeared from the universe when the "supersymmetry" broke just .000000000000000000000000000000000034 seconds after the Big Bang. Particle physicists hope to observe some when they finish building an atom-smasher at CERN in Europe around 2005, because the equipment that we have right now does not put enough power into the speeding particles.

It's where particle physics meets cosmology, because at the very first instants of the universe, little things played a huge role.

Anywho, for something along the lines of planetary discoveries, check out http://www.jtwinc.com/Extrasolar/. It's a place where the guy keeps up on all the extrasolar discoveries (both proved and not), and he also has beautiful art accompanying some of the older discoveries that he created from his imagination of what an alien world just might look like.