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Space Science

New Mineral Found In Meteorite 85

Posted by Soulskill
from the please-don't-call-it-unobtianium dept.
Virtucon writes "The new mineral was found embedded in the Allende meteorite, which fell to Earth in 1969. Since 2007, geologist Chi Ma of Caltech has been probing the meteorite with a scanning electron microscope, discovering nine new materials including panguite. 'Panguite’s primordial nature means that it was actually around before the Earth and other planets formed, meaning it can help scientists learn more about the conditions in the cloud of gas and dust that gave rise to our solar system.'"
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New Mineral Found In Meteorite

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  • by meglon (1001833) on Tuesday June 26, 2012 @11:45PM (#40462911)
    Certainly they could, however, given the distance to the closest star system from us, the travel times, the odds of hitting something as small as our planet with something even smaller from that distance, plus given the uncertainties of what actually lies between those systems and how that medium would interact with anything traveling through it, and even the unknown variable of what it would take to eject such an item from the originating system in the first place (not all systems are the same)... one would be far safer to go with the simplest answer, instead of opting for the answer that is so incredibly remotely possible.

    Just saying.... the simplest answer is usually the right one.
  • by Anonymous Coward on Wednesday June 27, 2012 @12:15AM (#40463161)

    From the Wikipedia (I'd never taint my honor by RTFA):

    "Panguite is in a class of refractory minerals that formed under the high temperatures and extremely varied pressures present in the early solar system, up to 4.5 billion years ago. This makes panguite one of the oldest minerals in the solar system. Zirconium is a key element in determining conditions prior to and during the solar system’s formation."

    I'm no chemist, but from that it seems they know when it was formed because of the temperature/pressure required to join the elements together (now how they know how things were back then I don't know). But yeah, it's a pain when so-called journalists write but don't communicate much of anything.

  • Andromeda Strain (Score:4, Informative)

    by rossdee (243626) on Wednesday June 27, 2012 @12:21AM (#40463209)

    "Panguite (IMA 2010-057), (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, is a new titania, occurring as fine-grained crystals with Ti-rich davisite in an ultra-refractory inclusion within an amoeboid olivine inclusion from the Allende CV3 carbonaceous chondrite."

    amoeboid?

    Uh-oh
    Better call in Dr Jeremy Stone and the Wildfire team

  • by Fred Ferrigno (122319) on Wednesday June 27, 2012 @12:38AM (#40463363)

    And now you know: [doi.org]

    We have studied Pb-isotope systematics of chondrules from the oxidized CV3 carbonaceous chondrite Allende. The chondrules contain variably radiogenic Pb with a (206)Pb/(204)Pb ratio between 19.5–268. Pb-Pb isochron regression for eight most radiogenic analyses yielded the date of 4566.2 ± 2.5 Ma. Internal residue-leachate isochrons for eight chondrule fractions yielded consistent dates with a weighted average of 4566.6 ± 1.0 Ma, our best estimate for an average age of Allende chondrule formation.

  • by polymeris (902231) on Wednesday June 27, 2012 @03:05AM (#40464239)

    Panguite (IMA 2010-057), (Ti4+,Sc,Al,Mg,Zr,Ca)1.8O3, is a new titania, occurring as fine-grained crystals with Ti-rich davisite in an ultra-refractory inclusion within an amoeboid olivine inclusion from the Allende CV3 carbonaceous chondrite.

    A titanium-bearing mineral has been accepted into the International Mineralogical Asoc.'s catalgoue. Chondrites are a class of meteorites, the important part being that they are supposed to have formed as such and were not part of a larger body. (No evidence of impact or melting).
    Some carbonaceous meteorites have large (several mm diameter) grains of material which were formed in vacuum, in particular those of the CV subtype. This particular meteorite's chrondrules (that's what those grains are called) contain refractory (i.e. heat-resistant) material in the amoeboid (rounded, irregular shape) olvine inclusions. Olivine is a basic ( = low silica content) mineral series common in celestial bodies (also the inner earth) and very suceptible to weathering, that is, exposure to water. Altered olivine has been found in fragments of meteorites from mars, which is the reason it is believed that there once was a water on that planet. But that's another story.

  • by Anonymous Coward on Wednesday June 27, 2012 @09:15AM (#40466253)

    You got most of it.

    IMA is the International Mineralogical Association, which certifies any new mineral claims and places them in an official catalog by that number. "Amoeboid" just means mineral grains "shaped like an amoeba", i.e. kind of "blobby" with lots of projections and embayments. This is pretty typical for olivine from this particular meteorite type (carbonaceous chondrite [wikipedia.org]) and the particular fall, Allende [wikipedia.org] (named after the place where it fell in Mexico -- this happens to be a particularly famous and well-studied fall, if not *the* most famous one. Hell, even *I* have a piece of this meteorite because there is so much of it. It's one of the cheaper ones to buy). "CV3" refers to the exact meteorite classification.

    Olivine [wikipedia.org] is a common iron-magnesium silicate mineral on the Earth, well known for forming the Earth's upper mantle, but perhaps better known as the gemstone peridot. As the "olive" name suggests, it is often greenish in colour (yellow-green is typical). The new mineral is found as an inclusion (i.e. inside) the olivine grains, and these inclusions are also amoeboid in shape. So, tiny blobs of Ti-rich minerals inside bigger, blobby-shaped olivine crystals. The new mineral is mixed as tiny (i.e. "fine-grained") crystals within davisite, a previously-known Ti-bearing mineral that also is common on Earth (and davisite compositions vary, so they mention that this is the Ti-rich version of it). The "ultra-refractory" part refers to the fact that the minerals involved in the inclusions have very high melting/vapourization temperatures (typical for Ti minerals), implying that if they solidified/condensed in the solar nebula, they were probably formed very early in the process as the stuff was cooling down, before the formation of the olivine grains that surround them. As such they may preserve the early history of this material as it started clumping together to form what eventually became a large meteorite chunk.

    Carbonaceous chondrites are special among meteorites because they preserve an early stage of the clumping together and differentiation of solar system material -- they didn't get big enough to melt most of their material and separate the denser metals into the core versus the crust and mantle, like happened on the Earth and all the other large planetary bodies and moons. They were "frozen" in a relatively unaltered state compared to larger bodies. It's kind of like you have all the ingredients for a nice cake (planet), but they got shoved into the freezer and left for a few billion years instead of getting cooked in the oven.

    Okay, okay, I'll try a car analogy. It's like you have the iron ore, aluminum ore, oil, sand, and all the other raw materials that go into manufacturing a car, but they haven't been processed yet. If you want to know how to build a car "from scratch", this could be useful material to compare to the finished product (the car being analogous to a planet in this case).

  • by CrimsonAvenger (580665) on Wednesday June 27, 2012 @11:34AM (#40467969)

    we can do some basic math to calculate travel time, if we make a few basic assumptions.

    The entry speed of a meteorite into our atmosphere is ~11-25km/sec. Using a high average of 20km.sec, and placing that as the average travel speed of the object (huge assumption)

    We can do some better calculations from those same numbers also.

    For instance, 11km/s relative to Earth is below solar escape speed, so a rock moving that fast did NOT come from outside the solar system (barring some really interesting interactions with multiple planets on entry to the Solar System - and we can't assume that condition existed for most (or even many) of the meteors arriving at the low end of meteor speeds).

    On the other hand, 25 km/s relative to Earth could be moving greater than solar escape speed, if it were moving more or less in the same direction Earth is at impact - if it's basically chasing Earth, then it's moving at about 31 km/s in excess of solar escape speed.

    On the other hand, if it's coming in at a larger angle relative to Earth's motion, then it may still be moving at less than solar escape speed. Coming in perpendicular to Earth's orbital motion, for instance, leaves it moving about 4 km/s BELOW solar escape speed.

    Which leave you with (assuming arbitrary of meteor orbits) less than half of all meteors coming in at the high-end of the speed range are interstellar, with an even small fraction of the slower ones being interstellar objects.

    Which leaves you with most of them being local, with no regards to travel time.

    Note, by the way, that travel time is pretty much irrelevant to the likelihood a rock came from around another star.

    Note also that your travel time estimates are off by a several orders of magnitude. You have the approximate distance in meters to Alphacent correct, but you then divide that by a speed in km/s (giving you an error of 3 orders of magnitude), then you compound that error by assuming that the result of that first division was time in YEARS instead of SECONDS (giving you an error of another seven orders of magnitude).

    The correct answer, by the by, for your numbers, is about 63000 years.

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