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A Little Piece of Mercury on Earth?
jonerik writes "While the discovery of meteorites believed to have originated on Mars is almost commonplace these days, the BBC is reporting the discovery of what is believed to be the first known chunk of the planet Mercury found on the Earth. The rock - actually discovered in 1999 and dubbed NWA 011 - has certain characteristics which lead experts to believe that it came from a body larger than an asteroid, and specifically from a planet."
Oooh, this chunk of rock came from Mars! This one's from Mercury! Hey, this one's from the planet KRYPTON! (is it green or red I wonder?)
/. wouldn't take the huge bn.com link.
All this stuff seems to be based on what Frazer called "the magical laws of similarity and contagion" rather than real science. I tried to link Frazer's magnum opus The Golden Bough here but
It's a logical fallacy to assume that object A was once a part of object B simply because they share the same composition; in fact it's a bad idea to blindly assume object A came from B even if A is identical to an object you know came from object B!
Pseudo-scientific psychobabble by fuzzy thinkers in search of grant money? Or just bad reporting?
Hopefully, by the repetitious reporting of finding a chunk of this planet or that comet, people on Earth will slowly come to this realization: Outer space ain't out there. We're in the middle of it, thinly shielded by air. We're in the midst of a game of cosmic whack-a-mole in a dangerously radioactive arena.
If we're going to survive, long term, we'd better learn to live in the environment surrounding us - not just Earth, but the solar system. We'd better learn how to duck - sooner or later, the chunk is going to be life-changing in size (http://impact.arc.nasa.gov/index.html) Soonest likely that we know of now is 2880 AD. We've only scanned a few percent of the sky looking out for this.
We're even threatened by the Sun that gives us power (http://antwrp.gsfc.nasa.gov/apod/ap020516.html). Don't think it's safe just cuz we haven't seen a big whack in recent history - people used to think that about Vesuvius and Karakatoa.
Pavlov wouldn't be so famous if he'd used a can opener instead of a bell.
You have a point, but the so-called Martian meteorites have been subject to a series of tests that make their origin all but certain. Their radio-date conforms to the cratering dates on Mars, their composition is in-line with Martian rocks analysed by landers, and most remarkably, gas bubbles in the rock have the same inert gas composition as readings taken by Viking.
Again the lunar meteorites have the same unique ratios of rare-Earth elements as known lunar samples.
These meteorites all come from places that have been subject to considerable geological processing - which is not the case for the vast majority of meteorites. Geological processing implies that the planets were hot and active for a long period of time, which implies large bodies. And there aren't many candidates.
Best wishes,
Mike.
As you say, the origin is "all but certain" - which is fundamentally different from "known" in a logical, scientific sense.
Read Kant, nothing is "known" in science.
Yours Sincerely, Michael.