Meteorite impacts leave behind time-capsules of ecosystems

Glass beads that form inside hot meteors as they fall to Earth capture particles from the atmosphere, creating a kind of permanent record of historic climates.

Meteorite impacts can be very destructive. One that fell in Mexico around 66m years ago created a 180km crater and caused the extinction of dinosaurs while spewing debris and molten rock into the air. Now, in what is a fascinating tale of serendipity, researchers have found that these events don’t entirely destroy all traces of life at the site of impact. Molten rocks can capture and preserve organic matter as they cool down to form glass beads.

When a meteor enters Earth’s atmosphere, the air around the meteor gets very quickly compressed causing it to heat up, scorching everything in its path. Most of the time that is where the story ends, as the meteor burns up in the sky as a “shooting star”. But sometimes it is big enough to reach all the way to the surface and transfer its remaining energy to the ground.

This energy is dissipated, as mild earthquakes, sound shockwaves – but mostly as heat. The heat energy can be so great that it melts rocks on the surface and hurls them up in the atmosphere. Anything that comes in contact with this molten rock would presumably get burnt, leaving nothing but rocky material that cools down in the atmosphere, forming glass beads and tektites (gravel-sized natural glass). This is what City University of New York researcher Kieren Howard assumed, but he was able to show that his assumptions were wrong.

For his PhD, Howard was studying the glass beads and tektites found near the Darwin crater in Tasmania. The 1.2km wide crater was created by a meteorite impact about 800,000 years ago.

The natural glass formed during cooling is (as implied by the term glass) not crystalline. Instead of a regular arrangement of atoms, the atoms inside it are randomly arranged. Howard’s analysis, however, kept showing the presence of crystals. At first, he dismissed this as a problem with the machine or with his method of analysis. But when it kept showing up, as a good scientist, he thought he should ask an expert to look at his data.

“This is unusual,” says Chris Jeynes, a physicist at the University of Surrey. “If there were indeed crystals, then it was the result of uneven cooling, which can occur when something gets trapped inside these glass beads.”

Jeynes used proton-beam analysis, a method to peer inside the glass to reveal its elemental make-up. Inside he found carbon. “Howard had no idea what his samples were, and he was very surprised when I told him,” Jeynes says.

The natural glass formed should contain only silicon, titanium, oxygen and other metallic elements in trace amounts. Detection of carbon meant that there was some organic matter inside. The only hypothesis was that, somehow during the formation of these glass beads, they captured organic matter that was floating in the atmosphere. That organic matter might have already been in the air, but it might also include material thrown up by the impact.

Howard then went to another expert to break open these glass beads and reveal what the carbon-rich matter was. It turned out that it included were cellulose, lignin and other biopolymers. This meant that somehow this matter, which originated from plants, had survived the temperature of more than 500°C, which is what the molten rock would have reached before cooling into a glass bead. Usually these temperatures will break down the organic matter, but clearly it didn’t in this case.

Mark Sephton, a geochemist at Imperial College London, was surprised and pleased: “What the results show is that these glass beads can capture an aliquot of the atmosphere of the planet at impact. It is like a time capsule of that ecosystem.” These results are published in Nature Geoscience.

The implications are enormous. It shows that other meteorite impacts, like the one that wiped out the dinosaurs, could have created such time capsules too. Sephton is now working on finding glass beads from other impact sites to reveal information about Earth’s ancient atmosphere.

This method of analysis means that we could also go looking for similar beads on other planets, like Mars, where meteorite impacts are common. They could also reveal vital information about the past atmosphere of those planets. Maybe they captured organic matter – if it ever existed there.

“We would not know any of this if it wasn’t for Howard,” Jeynes says, adding that Howard’s persistence to find out what “the wrong results” led the researchers to a phenomenon that nobody knew existed.

This article was originally published at The Conversation. Read the original article.

The Conversation

Meteor Crater in Arizona. (Photo: Angle Schatz/Flickr)
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Why I refuse to complain about email spam

The bleaker things get, the easier it is to be annoyed about absolutely everything.

“I need just one night and your cock
I want to give you a [sic] head Nice [sic] ginger hair and big bubbly boobs”

It reads like poetry. Poetry by an early 00s DVD player that has recently mastered the English language and doesn’t know what to do with it. A DVD player that’s lying on a skip and has a discarded Cornetto sitting atop its plastic exoskeleton like a depressing party hat, sluggishly oozing ice cream into all its crevices. Yes. If a broken and abandoned DVD player were to start writing poems, they’d probably look a bit like that stunningly naïve and post-post-modern cock and bubbly boobs mess.

Innermost contemplations of an obsolete piece of technology or not, these lines of poetry recently appeared in my email junk folder. Subject line: “Sex right now.” Sender: “Teresa Hughes”.

The bleaker things get (economically, politically, socially) the easier it is to complain about absolutely everything. Knowing that I’ll probably spend the rest of my life either living with my parents or renting shitholes from miserly Dickensian landlords makes selfie sticks all the more annoying. And slow walkers. And rugby fans. And people who stand on street corners, shouting about Jesus and doom. All of these things, within the context of generalised rubbishness, are worthy of a billion pissed off tweets.

Spam, on the other hand, the bugbear of the privileged but stressed since about 1996, is one of the increasingly few things about which I refuse to complain. Reason being: spam, the porny kind in particular, has always been there for me… in a way.  

I can’t remember my first email address. Knowing prepubescent me, it was probably a) boringly weird and b) just a fucking abomination. Something like What I can remember though is being emailed about blowjobs way before I knew what they were. Which was, in a sense, educational.

Over the past few days, my junk folder has been inundated by requests from robots who want to do stuff to my penis. This is my first incursion of porn spam in a long while; years, possibly. And I’m finding it almost impossible to be annoyed or disgusted by it. Instead, I’ve been getting nostalgic. Nostalgic for a simpler digital time. A time in which connecting to the internet made a sound like an android with norovirus, and people were trusting enough to click on links in emails with subject lines like, “Mega-PU$$Y 4 U!!!!”.

I like to imagine that, over the next century, great leaders will come and go; empires will rise and fall; bootcut jeans will have moments of fashionableness roughly every fifteen years; and, all the while, people like “Teresa Hughes” will email us reminders that they would dearly like to suck us off, in exchange for a hard drive-melting virus.

Plus, I was only being a little bit facetious about that “poem” thing. When I did an art history elective at uni, a lot of it was spent gazing at pictures of Marcel Duchamp’s “Fountain” (that urinal that’s art) and wondering what art actually is. Can a urinal be art? Can Danny Dyer be art? And, most pressingly, can spam be art? In one word: sure.

Let’s return our attention to those lines of spam at the beginning of the piece. I shall now attempt to apply GCSE-level analysis to Sex Now by “Teresa Hughes” (the lesser-known offspring of Ted and Sylvia, presumably).

The speaker, a woman, in a grab for immediate attention, addresses the reader directly. The line break after “cock” places emphasis on that word, reassuring the reader just how much she “needs” his/her penis. The unusual phrasing in the next line, “a head”, rather than “head”, for example, is a play on words that neatly juxtaposes [seriously, how much did you use the word “juxtapose” in GCSE English essays?] the primal act of giving head with the intellectual act of having one (and using it).  The alliteration in “big bubbly boobs” highlights the exact largeness and roundness pertaining to the speaker’s breasts. Furthermore, she wants us to know that her horniness transcends grammar.

Even furthermore, spam is literature and the world would be a darker place without it. So don’t be a great honking philistine and complain about it.

Eleanor Margolis is a freelance journalist, whose "Lez Miserable" column appears weekly on the New Statesman website.