Origin Of ‘Mercury’ Meteorite Still Puzzles Scientists

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A strange green rock discovered in Morocco last year was hailed by the press as the first meteorite from Mercury. But scientists who've been puzzling over the stone since then say the accumulating evidence may point in a different direction. Maybe, just maybe, they say, the 4.56-billion-year-old rock fell to Earth from the asteroid belt located between Mars and Jupiter.


If that's true, the rock is "still extremely interesting," says Tim McCoy, who curates the Smithsonian Museum of Natural History's collection of 35,000 meteorites. "[It] tells us something about the birth of the solar system, but not the birth of the innermost planet."

The olive green meteorite, flecked with bits of white and brown, first came to scientists' attention last year when a German collector, Stefan Ralew, saw the unusual stone in Morocco and shipped it off for analysis to Tony Irving, a geochemist and meteorite specialist affiliated with the University of Washington in Seattle. Irving routinely receives such packages from all over the world.

"From experience, I knew it was very unlikely to be an Earth rock," Irving says. "It wasn't from Mars, and if it was a meteorite, it was highly unusual." As it turns out, the rock was even weirder than it looked.

Written By: Geoff Brumfiel
continue to source article at npr.org

8 COMMENTS

  1. Puzzling meteorite from Mercury? My kitchen surfaces can end up looking this colourful after a curry preparation! I think it may have been temporarily dipped in a solution of turmeric, saffron, chilli and mustard, that’s usually the most colourful combination, and the most stubborn to get rid off.
    Was God making a curry?

  2. @link – “There was nothing that jumped out and said, ‘No, this can’t be from Mercury,’ ” she says, “but there were a few bits that didn’t quite match with Mercury.” For example, the rock lacks sulfur, while Mercury’s surface is covered in it.

    That would suggest that it cannot have been blasted off Mercury recently.

    The Smithsonian’s Tim McCoy has a problem with the rock’s age.

    “The meteorite is very, very old — 4.56 billion years old,” he says. “So it’s essentially formed at the same time as the birth of the planet, whereas Mercury is a huge, hot planet that probably wouldn’t have cooled off enough to have solid rock 4.56 billion years ago.”

    This suggests that it could not be from Mercury when first launched into space (at least not if Mercury was in its present orbit!), although there were many colliding small rocky planets, planetesimals, and moons in the early Solar-System.

    • In reply to #2 by Alan4discussion:

      @link – “There was nothing that jumped out and said, ‘No, this can’t be from Mercury,’ ” she says, “but there were a few bits that didn’t quite match with Mercury.” For example, the rock lacks sulfur, while Mercury’s surface is covered in it.

      That would suggest that it cannot have been blasted off Mercury recently.

      The Smithsonian’s Tim McCoy has a problem with the rock’s age.

      “The meteorite is very, very old — 4.56 billion years old,” he says. “So it’s essentially formed at the same time as the birth of the planet, whereas Mercury is a huge, hot planet that probably wouldn’t have cooled off enough to have solid rock 4.56 billion years ago.”

      This suggests that it could not be from Mercury when first launched into space (at least not if Mercury was in its present orbit!), although there were many colliding small rocky planets, planetesimals, and moons in the early Solar-System.

      The sulfur seems to clinch it, but if something hit a liquid-state Mercury, wouldn’t the ejecta quickly cool to solid rock in space..?

      • In reply to #6 by prettygoodformonkeys:

        The sulfur seems to clinch it, but if something hit a liquid-state Mercury,

        The sulphur could be a more recent feature of Mercury. Mercury has had the Sun boiling off its lighter elements into space for millennia. It still has a comet like tail of lost atmosphere today.

        wouldn’t the ejecta quickly cool to solid rock in space..?

        It would, but it would look like solidified magma, – (probably full of cavities from gases boiling off in vacuum,) not shattered jagged pieces of solid rock. Just as geologists on Earth can tell the history of a rock from its structure, meteorites can be analysed to understand their formation, even if the outer layers have been fried coming through Earth’s atmosphere.

  3. So, calling it the “Mercury” meteorite is a bit shabby, no? I guess as long as the word Mercury is in quotes, we all get it. Like calling the pope “good”. Or calling the pope a “chemical technician”….

  4. Don’t think much of this article; Irving seems to have as much evidence for the rock coming from Mercury as there is evidence for it coming from, er, anywhere else in the solar system, except Mars of course.
    As for calling Irving’s proposal at the conference a theory, well that just undermines everything Richard Dawkins and Eugene Scott taught me about the difference between a scientific theory and the theories I come up with down the pub.
    Unless of course, Sheldon Cooper is right,” Geology is not a real science”.

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