"Earth/Mars/Moon have different origin" Topic

link

Interesting little tidbit…

Last quote in the article sums it up;

"To think that we can get definitive information about the bulk composition of Mars from a handful of meteorites," he said, "all likely from the same area of the Martian crust, is very optimistic."

Early days and it seems to ignore the effects of differentiation.

ok…that does it! We're going to have to send a scouting party out in Mr. Peabody's WAYBACK machine and get it on videophone…

(then we can put the hi-speed video on youtube!!)

*slish…slish*

Sgt DWW-bartentacle on duty

Thanks for that Mardaddy. Interesting.

Tony
occultwars.com

I have always wondered how anyone can definitively say that "this" meteorite is of lunar origin, and "that" one comes from Mars. No one has been able to explain that to me.

God put them there, JOhn.
--
Tim

Well, that explains it. Explains pretty much everything, too!

Yeah, good ol' Deus ex Machina. We owe those Greeks a lot!

Moon meteorites are comparisons with Apollo lunar samples. They are also extremely rare – the total allotment numbering something less than 3 lbs or something.

The same is true for comparisons of gas bubbles within meteorites that correspond within a very slight molecular composition range of those constituent with Mars via Viking readings. Also, many of the certified Mars rocks were actually observed to fall. As it is right now, there are only 22 (?) certified Mars rocks. IIRC, Antarctica has the most strikes of both Lunar and Mars rocks. Other observed meteors can be backtracked to a likely origin. Most though come from the asteroid belt.

Lastly, age of the rock's formation is indicative. At 4.5 billion years old, the rock likely came from the asteroid belt. If younger, say around 1.5 billion, then it is likely the rock came from a geologic source of high activity at that point like Mercury, Venus, or Mars. Hope this helps.

So "Martian" meteorites were observed to fall? Again, how do you know they came from Mars, unless "directly".

As I understand orbital calculations, there are only so many options available to a rock on a given course, given velocity, given insertion, etc. So, our typical meteor can be calculated out to where it arrived from given its orbital insertion and location.

As to whether the rock may have come from Mars many many years ago, or the astroid belt, or somewhere else, composition data and examination of the rock determine its origin. Something like 86% of meteorites that have been recovered contained chrondites – which are just rounded particulate silicates that formed billions and billions of years ago. These are such old formations that they certainly come from the asteroid belt and are leftovers from bits that were not formed into planets.

The other very small percentage contains achrondites which were formed in higher gravity environments. Of these, many of these are similar in age, make-up, and form to those recovered by the Apollo missions. These are likely leftover strikes of Moon bits. The other even smaller percentage bears almost exact correlation to data from Viking's readings of Martian regolith and match each other. These data include chemical, isotopic, and petrologic compositions that are dead ringers for what the Viking missions had.

You probably could not confirm without a shadow of doubt about a meteorite's origin without analyzing it's makeup. While thousands of meteorites hit the Earth each year, calculations may only get you so far depending on how long a given rock has been able to be observed. So, assuming the observation aspect falters, the best answer as to where it comes from is by recovering the rock and seeing where the data of its composition leads you.

The easy explanation (AFAICT) is that the Earth, Moon, and Mars all belong here. However, whatever body the asteroid belt came from was an interloper from elsewhere that was captured and ripped apart by tidal forces.

Some of the identification is performed by mass spectrometry. A particular ratio of some isotopes supports other evidence of a body's origin. One of the seven MSes capable of that work used to be around the corner and upstairs from where I'm typing this. I don't know what became of it after that guy retired.