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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Marcus Hutchins: What we know so far about the arrest of the hero hacker

The 23-year old who stopped the WannaCry malware which attacked the NHS has been arrested in the US. 

In May, Marcus Hutchins - who goes by the online name Malware Tech - became a national hero after "accidentally" discovering a way to stop the WannaCry virus that had paralysed parts of the NHS.

Now, the 23-year-old darling of cyber security is facing charges of cyber crime following a bizarre turn of events that have left many baffled. So what do we know about his indictment?

Arrest

Hutchins, from Ilfracombe in Devon, was reportedly arrested by the FBI in Las Vegas on Wednesday before travelling back from cyber security conferences Black Hat and Def Con.

He is now due to appear in court in Las Vegas later today after being accused of involvement with a piece of malware used to access people's bank accounts.

"Marcus Hutchins... a citizen and resident of the United Kingdom, was arrested in the United States on 2 August, 2017, in Las Vegas, Nevada, after a grand jury in the Eastern District of Wisconsin returned a six-count indictment against Hutchins for his role in creating and distributing the Kronos banking Trojan," said the US Department of Justice.

"The charges against Hutchins, and for which he was arrested, relate to alleged conduct that occurred between in or around July 2014 and July 2015."

His court appearance comes after he was arraigned in Las Vegas yesterday. He made no statement beyond a series of one-word answers to basic questions from the judge, the Guardian reports. A public defender said Hutchins had no criminal history and had previously cooperated with federal authorities. 

The malware

Kronos, a so-called Trojan, is a kind of malware that disguises itself as legitimate software while harvesting unsuspecting victims' online banking login details and other financial data.

It emerged in July 2014 on a Russian underground forum, where it was advertised for $7,000 (£5,330), a relatively high figure at the time, according to the BBC.

Shortly after it made the news, a video demonstrating the malware was posted to YouTube allegedly by Hutchins' co-defendant, who has not been named. Hutchins later tweeted: "Anyone got a kronos sample."

His mum, Janet Hutchins, told the Press Association it is "hugely unlikely" he was involved because he spent "enormous amounts of time" fighting attacks.

Research?

Meanwhile Ryan Kalember, a security researcher from Proofpoint, told the Guardian that the actions of researchers investigating malware may sometimes look criminal.

“This could very easily be the FBI mistaking legitimate research activity with being in control of Kronos infrastructure," said Kalember. "Lots of researchers like to log in to crimeware tools and interfaces and play around.”

The indictment alleges that Hutchins created and sold Kronos on internet forums including the AlphaBay dark web market, which was shut down last month.

"Sometimes you have to at least pretend to be selling something interesting to get people to trust you,” added Kalember. “It’s not an uncommon thing for researchers to do and I don’t know if the FBI could tell the difference.”

It's a sentiment echoed by US cyber-attorney Tor Ekeland, who told Radio 4's Today Programme: "I can think of a number of examples of legitimate software that would potentially be a felony under this theory of prosecution."

Hutchins could face 40 years in jail if found guilty, Ekelend said, but he added that no victims had been named.

This article also appears on NS Tech, a new division of the New Statesman focusing on the intersection of technology and politics.

Oscar Williams is editor of the NewStatesman's sister site NSTech.