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.

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Meteor Crater in Arizona. (Photo: Angle Schatz/Flickr)
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Did your personality determine whether you voted for Brexit? Research suggests so

The Online Privacy Foundation found Leave voters were significantly more likely to be authoritarian and conscientious. 

"Before referendum day, I said the winners would be those who told the most convincing lies," Paul Flynn, a Labour MP, wrote in these pages. "Leave did." The idea that those who voted for Brexit were somehow manipulated is widely accepted by the Remain camp. The Leave campaign, so the argument goes, played on voters' fears and exploited their low numeracy. And new research from the Online Privacy Foundation suggests this argument may, in part at least, be right. 

Over the last 18 months the organisation have researched differences in personality traits, levels of authoritarianism, numeracy, thinking styles and cognitive biases between EU referendum voters. The organisation conducted a series of studies, capturing over 11,000 responses to self-report psychology questionnaires and controlled experiments, with the final results scheduled to be presented at the International Conference on Political Psychology in Copenhagen in October 2017.

The researchers questioned voters using the "Five Factor Model" which consists of five broad personality traits - Openness, Conscientiousness, Extraversion, Agreeableness and Neuroticism. They also considered the disposition of authoritarianism (it is not considered a personality trait). Authoritarians have a more black and white view of the world around them, are more concerned with the upkeep of established societal traditions and have a tendency to be less accepting of outsiders. 

So what did they uncover? Participants expressing an intent to vote to leave the EU reported significantly higher levels of authoritarianism and conscientiousness, and lower levels of openness and neuroticism than voters expressing an intent to vote to remain. (Conscientiousness is associated with dependability, dutifulness, focus and adherence to societal norms in contrast to disorganisation, carelessness and impulsivity.)

Immigration in particular seems to have affected voting. While authoritarians were much more likely to vote Leave to begin with, those who were less authoritarian became increasingly likely to vote Leave if they expressed high levels of concern over immigration. These findings chime with research by the Professors Marc Hetherington and Elizabeth Suhay, which found that Americans became susceptible to "authoritarian thinking" when they perceived a grave threat to their safety. 

Then there's what you might call the £350m question - did Leave voters know what they were voting for? When the Online Privacy Foundation researchers compared Leave voters with Remain voters, they displayed significantly lower levels of numeracy, reasoning and appeared more impulsive. In all three areas, older voters performed significantly worse than young voters intending to vote the same way.

Even when voters were able to interpret statistics, their ability to do so could be overcome by partisanship. In one striking study, when voters were asked to interpret statistics about whether a skin cream increases or decreases a rash, they were able to interpret them correctly roughly 57 per cent of the time. But when voters were asked to interpret the same set of statistics, but told they were about whether immigration increases or decreases crime, something disturbing happened. 

If the statistics didn't support a voter's view, their ability to correctly interpret the numbers dropped, in some cases, by almost a half. 

Before Remoaners start to crow, this study is not an affirmation that "I'm smart, you're dumb". Further research could be done, for example, on the role of age and education (young graduates were far more likely to vote Remain). But in the meantime, there is a question that needs to be answered - are political campaigners deliberately exploiting these personality traits? 

Chris Sumner, from the Online Privacy Foundation, warns that in the era of Big Data, clues about our personalities are collected online: "In the era of Big Data, these clues are aggregated, transformed and sold by a burgeoning industry."

Indeed, Cambridge Analytica, a data company associated with the political right in the UK and US, states on its website that it can "more effectively engage and persuade voters using specially tailored language and visual ad combinations crafted with insights gleaned from behavioral understandings of your electorate". It will do so through a "blend of big data analytics and behavioural psychology". 

"Given the differences observed between Leave and Remain voters, and irrespective of which campaign, it is reasonable to hypothesize that industrial-scale psychographic profiling would have been a highly effective strategy," Sumner says. By identifying voters with different personalities and attitudes, such campaigns could target "the most persuadable voters with messages most likely to influence their vote". Indeed, in research yet to be published, the Online Privacy Foundation targeted groups with differing attitudes to civil liberties based on psychographic indicators associated with authoritarianism. The findings, says Sumner, illustrate "the ease with which individuals' inherent differences could be exploited". 

Julia Rampen is the digital news editor of the New Statesman (previously editor of The Staggers, The New Statesman's online rolling politics blog). She has also been deputy editor at Mirror Money Online and has worked as a financial journalist for several trade magazines. 

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