Meteorites

[Pliosaur]

Are meteorites considered fossils?

Gabriel

[Missourian]

No, but I suppose you could refer to some as 'fossilized solar nebula'.

[fossilized6s]

To be considered a fossil it had to be a living organism at one point.

Edited March 29, 2014 by fossilized6s

[NZ_Fossil_Collecta]

no, but it doesn't make them any less cool. especially since some come from the moon or mars.

[CH4ShotCaller]

It's true, it would have to be a living organism at one point, but nonetheless fascinating pieces to find and admire. If you ever find one that contains a fossil, you'd be famous for finding life beyond our planet. Unless it was terrestrial ejecta from a prior impact event, but you'd still gain more than 15 minutes of fame.

[fossilized6s]

I own a huge Meteorite. Wanna see it?

[Mediospirifer]

I own a huge Meteorite. Wanna see it?

Sure!

[Mediospirifer]

Are meteorites considered fossils?

Gabriel

Most meteorites are older than the Earth. The chondrite meteorites are basically leftover material from the protoplanetary disk. Achondrites are from other planetary bodies, including the Moon and Mars, and are usually younger rocks.

Some people have claimed to have found bacteria in meteorites, but none of these claims has been substantiated. The best-known example was a martian meteorite found in Antarctica which had some interesting structures visible under the electron microscope as well as some organic compounds. So far, it's judged simpler for these to have formed by nonliving processes. Scientifically, life is a very complicated process, especially where it hasn't yet been found!

One recent claim involves the Orgueil meteorite. That one is a carbonaceous chondrite that fell in 1864. Someone recently claimed to have found bacteria in the piece they had access to, although it isn't possible to rule out contamination with Earthly bacteria in a meteorite that has been stored in a cabinet for 150 years. Not to mention, there are a lot of mineral grains than have similar shapes to bacteria!

There have been other claims, but so far none of them have stood up under scientific examination and critical analysis. It would be very, very cool to have a genuine discovery of unambiguous signs of life in a meteorite, especially one that didn't originate on Earth in the first place! For the record, there aren't any meteorites that are known to have originated on Earth. It would take a Chicxulub-magnitude impact to launch rocks off of the Earth, and most of those would fall back within the first 10 million years. Or so I've read--I haven't done the math myself, but I did go looking online.

[fossilized6s]

Here's my big guy. It's about 70lbs. I inherited this after my uncle passed. He was a professional custom knife maker. And he would mix the meteorite into the blades. This is almost pure iron.

[Pliosaur]

Wow! That is big!

[NZ_Fossil_Collecta]

wanna see my lunar one? it's tiny but it originates from the moon. i also have some tiny pieces of a martian one, if you wanna see that.

[NZ_Fossil_Collecta]

Here's my big guy. It's about 70lbs. I inherited this after my uncle passed. He was a professional custom knife maker. And he would mix the meteorite into the blades. This is almost pure iron.

2014-03-29_07-32-46_350.jpg

2014-03-29_07-33-00_58.jpg

that's amazing... you can see all the "thumbrints" from where it was melting. that is amazing.

[Mediospirifer]

Here's my big guy. It's about 70lbs. I inherited this after my uncle passed. He was a professional custom knife maker. And he would mix the meteorite into the blades. This is almost pure iron.

2014-03-29_07-32-46_350.jpg

2014-03-29_07-33-00_58.jpg

Very nice! Do you know where it was collected? I can think of a few places where pieces like that have been collected, starting with Barringer's Crater in Arizona and Odessa Crater in Texas.

Did your uncle set pieces of the meteorite into the blade handles for decoration? I've seen a couple of very cool knives with that (at a sporting goods shop in Maine). They were priced at close to my budget for the whole trip! Suffice to say, we were not expecting to see meteorites when we walked into the shop and started looking at knives....

wanna see my lunar one? it's tiny but it originates from the moon. i also have some tiny pieces of a martian one, if you wanna see that.

Sure! I'll post a few of my pieces, too. My biggest piece is just over 3 lbs, not 70, but I have a variety of smaller pieces. I have a large collection of small meteorites.

[fossilized6s]

Very nice! Do you know where it was collected? I can think of a few places where pieces like that have been collected, starting with Barringer's Crater in Arizona and Odessa Crater in Texas.

Did your uncle set pieces of the meteorite into the blade handles for decoration? I've seen a couple of very cool knives with that (at a sporting goods shop in Maine). They were priced at close to my budget for the whole trip! Suffice to say, we were not expecting to see meteorites when we walked into the shop and started looking at knives....

Sure! I'll post a few of my pieces, too. My biggest piece is just over 3 lbs, not 70, but I have a variety of smaller pieces. I have a large collection of small meteorites.

I would love to see some more meteorites!

My uncle actually use to melt it down and mix it with steel. It would give it an agatized look. I do believe he got it in AZ, im not 100% though.

[Ludwigia]

Here's my big guy. It's about 70lbs. I inherited this after my uncle passed. He was a professional custom knife maker. And he would mix the meteorite into the blades. This is almost pure iron.

2014-03-29_07-32-46_350.jpg

2014-03-29_07-33-00_58.jpg

That's a great chunk! Fantastic inheritance!

[Mediospirifer]

I would love to see some more meteorites!

My uncle actually use to melt it down and mix it with steel. It would give it an agatized look. I do believe he got it in AZ, im not 100% though.

If it's from Arizona, it's probably a Canyon Diablo. That's the official name for the Barringer's Crater meteorites.

It's interesting that he melted it down and got an agatized look from the resulting alloy. Meteoritic iron is actually an alloy of nickel and iron, with other trace elements, where the amount of nickel varies from 5% to 25% depending on the piece. Canyon Diablo is typically 7.1% nickel, according to the Meteoritical Bulletin.

If you were to wash one of the cut faces with nitric acid, the crystal structure (Widmanstatten pattern) would become visible. There's some good photos on MetBull if you're curious: LINK

I'm currently putting together a meteorite display for a planetarium show next Friday. I'll take some pictures while I'm working on it and post them.

[fossilized6s]

Thanks for the info. I was going to sand it down and polish it.

[Mediospirifer]

I'd recommend sanding and polishing before etching with acid. And, of course, I'd leave the natural surface unaltered. Here's a link to a page describing how to do it: LINK

I haven't done it myself, but I know someone who has.

If you're interested in meteorites, there's an online forum that you might like. Club Space Rock

Enjoy!

[NZ_Fossil_Collecta]

here are pictures of my lunar and martian meteorites, as well as my iron and stone ones.

the lunar meteorite display case is approx 6cm long, for scale. for the martian one, the crumbs weigh about 1 mg. the iron one weighs about 25 grams.

<--- tiny piece of Dhofar 461 lunar meteorite from oman.

<--- Campo del cielo iron meteorite from argentina.

<--- stone metorite from morocco, wedge slice.

<--- 1mg of martian meteorite crumbs, NWA 6963. i made the label for this one.

Edited March 30, 2014 by NZ_Fossil_Collecta

[NZ_Fossil_Collecta]

I'd recommend sanding and polishing before etching with acid. And, of course, I'd leave the natural surface unaltered. Here's a link to a page describing how to do it: LINK

I haven't done it myself, but I know someone who has.

If you're interested in meteorites, there's an online forum that you might like. Club Space Rock

Enjoy!

i'm a member of that, but don't go on it as much as TFF

[painshill]

The original question “are meteorites considered fossils?” has a pretty emphatic “no” as the answer… but rephrasing the question to “can meteorites be fossilised?” has a somewhat different answer.

The Nomenclature Committee (Nom Com) of the International Meteoritical Society (IMS) recognises the term “relict meteorite” as follows:

“Special provisions are made in these Guidelines for highly altered materials that may have a meteoritic origin, designated relict meteorites, which are dominantly (>95%) composed of secondary minerals formed on the body on which the object was found. Examples of such material may include some types of meteorite shale, fossil meteorites and fusion crust.”

Fossil meteorites are also sometimes called Palaeo-Meteorites. In addition to meteorites where the original extra-terrestrial minerals have been replaced by terrestrial material in processes akin to those which occur during the mineralisation of organic fossils, the term may also apply to those where meteoritic material has become incorporated into terrestrial rocks – for example as indurated conglomerate.

A case in point is the meteorite Al Haggounia 001, which is “paired” with the meteorites NWA 2828/NWA 2965, probably also with NWA 002, NWA 1067 and NWA 2736 and perhaps others too (ie these finds represent different strewn fields which are all part of what must have been a massive fall). The first finds were in a fossil sabkha (saline playa) lake bed near Al Haggounia, Saguia el-Hamra, in the Western Sahara of Morocco in 2006. The fall is nevertheless not truly ancient compared to most organic fossils - Accelerator Mass Spectrometry indicates a terrestrial age of 23,000 ± 2000 years, during the Pleistocene Epoch.

Here’s a slice from my collection:

Al Haggounia 001 was formally classified as an aubrite meteorite and the (now believed) various partners as either aubrite, EL6 chondrite (or just E chondrite). The aubrite classifications were based in part on analyses by Bunch & Wittke and by Irving. All three authors have now retracted their opinions with an apology (via publication) and said that the aubrite classification was a “blatant error” arising from sampling difficulties and confusions from the high degree of terrestrial alteration together with the conglomerate nature of meteoritic material mixed with terrestrial material. Despite them having submitted revised classifications to the IMS in 2007, the Nom Com has apparently ignored them and declined to publish any corrections in their bulletin. The revised proposal is that the entire group of meteorites should be classified as unequilibrated enstatite chondrites (EL3) with Al Haggounia qualified as anomalous and having a weathering grade of W4.

Although the meteoritic nature is characterized by being rich in enstatite with plagioclase, terrestrial weathering has depleted the iron and nickel, leaving voids that have filled with calcite, gypsum and other terrestrial minerals. This, together with high levels of oxidation has created in many samples the appearance and mineralogy of a sedimentary breccia cemented by iron oxides, hydroxides and calcium carbonate.

The Orgueil meteorite shower (which fell in France in 1864) is steeped in controversy. Although the fall was a primitive carbonaceous chondrite (classified as a CI), the historical claims for the carbon having a biological origin were nonsense and fraudulent attempts were made at the time to reinforce that nonsense. That fraud was not apparent until 1965 when a fragment that had been sealed in a glass jar since 1864 was found to have seed capsule embedded in it, underneath the fusion crust. The seed was established to be from a European rush, glued into the meteorite and disguised with a mixture of glue and coal dust to simulate a crust.

Before that was known, Nagy et al. announced in 1962 that they had found “biological structures of extraterrestrial origin” in another fragment. Those “structures” proved to be terrestrial contaminants that included pollen (some of which was from ragwort) and fungal spores.

Richard B. Hoover of NASA also claimed the presence of fossil cyanobacteria and other prokaryote life-forms in Orgueil (and other) carbonaceous meteorites in an independently-authored 2011 paper in the Journal of Cosmology, which he published behind NASA’s back. The journal has a reputation for promoting “fringe-science” and NASA was openly critical of the conclusions and the totally inadequate peer-review. Disowning the work, Carl Pilcher, director of NASA's Astrobiology Institute said:

“I am not aware of any support from other meteorite researchers for this rather extraordinary claim that this evidence of microbes was present in the meteorite before the meteorite arrived on Earth and was not the result of contamination after the meteorite arrived on Earth.” Given that the studied meteorites fell to Earth 100 to 200 years ago and were heavily handled by humans he added: “so you would expect to find microbes in these meteorites” (and in fact Hoover himself commented on the similarities to microbes found on Earth).

As for Earth meteorites, it has been estimated that landmass impacts with an energy in excess of 106 Mt of TNT could be capable of ejecting fragments of Earth material up to 1km in size into orbit. An impact of this size occurs on average roughly every 25-30 million years. Meteorites falling back to Earth which have arisen from such events would be called “territes” or “terrene meteorites”, but none have been confirmed to date.

There has however been much speculation from the study of the meteorite NWA 5400 and its probable pairings, NWA 5363, NWA 6077 and NWA 6292. Initially NWA 5400 was believed to belong to the rare group of primitive achondrite meteorites known as brachinites, for which the parent body is perhaps the asteroid 289 Nenetta. But NWA 5400 differs from that group in having an anamolous (later) age for an early Solar System primitive achondrite and having oxygen isotope ratios which plot on what is known as the “terrestrial fractionation line” (TFL).

Those plots, in combination with the mineralogy, suggested it was somehow “Earth-related” or arose from an unknown (and no longer existent) differentiated body similar to Earth which accreted at around the same time. The early proto-Earth is thought to have experienced dozens of collisions with other bodies of planetary size and our Moon is believed to have been created from the coalesced debris of one such collision. The impactor has been theorised as a Mars-sized body (given the name “Theia”) and the debris cloud would have contained material from both planets – which would likely have had similar compositions. The possibility that NWA 5400 arose as a stray terrene or Theian meteorite from that collision has now been ruled out (based on its age) but it’s not possible to definitively say that it didn’t arise from an earlier collision. It’s significantly younger than other brachinites, but a little older than the theorised Earth-Theia collision.

Edited March 31, 2014 by painshill

[Mediospirifer]

Thank you, Painshill! I knew there was more than one claim of bacteria involving Orgueil, but I hadn't heard about the embedded rush-seed! That's a rather extreme attempt at fakery.

I like your quotes about the Journal of Cosmology. I've looked at a couple of articles in there that were pretty bad. I like the abbreviation I've seen for it: JoC (pronounced as a single syllable with a long 'o' and hard 'C'). I find that appropriate.

[auximenes]

Here's my big guy. It's about 70lbs. I inherited this after my uncle passed. He was a professional custom knife maker. And he would mix the meteorite into the blades. This is almost pure iron.

Awesome, thanks for sharing.