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Using Nuclear Bombs to Fight Wildlife Poachers

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During the 1950s and '60s, the United States and the Soviet Union tested and showed off their shiny new atomic arsenals by detonating hundreds of nuclear weapons at above-ground sites. After each explosion, residual radioactive material, or fallout, was dispersed into the atmosphere and then spread around the world by the wind. 

Among these radioactive leftovers is an isotope, or variant, of the element carbon known as carbon-14. This same isotope is generated naturally by cosmic rays and normally occurs in small traces, accounting for just one part per trillion of atmospheric carbon. During the Cold War, though, scientists keeping tabs on the isotope’s concentration found a spike—a near doubling—in carbon-14 levels that coincided with the start of the weapons tests, and a slow, steady decline when the tests were moved underground. It was dubbed the “bomb curve.”

Most carbon-14, whether it’s natural or man-made, American or Soviet, oxidizes into carbon dioxide, and then gets taken in by the oceans and by plants. As animals eat these plants and other animals eat those animals, almost every living thing gets a share of carbon-14 incorporated into its teeth or tusks or hair or horns. 

Anyone or anything that was alive during the Cold War got to keep a small souvenir from it inside its body—not enough to do any damage, but enough to date it. If the carbon-14 concentration in some animal or plant tissue is the same as the known level in the atmosphere at a certain date along the bomb curve, that gives you an idea of how old the tissue and the creature it came from is. 

In a study led by doctoral student Kevin Uno, a team of researchers from the University of Utah chased down more than two dozen animal tissue samples that had been collected between 1955 and 2008. Previous studies on bomb curve carbon dating had mostly only looked at tree rings and enamel from human teeth, but Uno and company gathered everything from hair from a blue monkey to teeth from hippos and tusks from elephants to stems from various plants. They measured the carbon-14 levels in these samples and then plotted them along the bomb curve to estimate when the sample was collected (which is usually right around when the animal died). For some of the samples, including tusks from elephants that had died in a zoo and in a national park, they knew the animals’ actual ages, and found their estimations were accurate within a year. 

The Nuclear Response

That the technique worked so well in a variety of tissues might make it a useful forensic tool to battle poachers. 

Every year, an estimated 30,000 African elephants are killed illegally for their ivory tusks. With only some 400,000 animals left in the wild, this kind of slaughter could make the species extinct in just a little over a decade. Poaching and the illegal ivory trade are big business, and those trying to stop it are up against organized and well-armed criminal organizations, corrupt government officials and a quirk in the law. 

International treaties have banned the trade of Asian elephant ivory since 1976, and African elephant ivory since 1989, but the laws allow for some loopholes. In some countries, including the United States, any ivory acquired before ’89 is legal to buy and sell. Trying to distinguish legal, pre-ban ivory from poached, post-ban ivory has been incredibly difficult, and ivory traders can move ill-gotten product by claiming that it’s older than it really is. Carbon dating an ivory sample against the bomb curve, though, can date it and reveal how old and how legal it is. It’s science calling BS on poachers and their marketplace enablers. 

Uno’s work complements research done at the University of Washington, which uses DNA and isotope analysis to locate the origin point of ivory. Working out the “when and where” of confiscated ivory (and other animal parts, like rhino horns) can help shut down individual dealers but also identify poaching hot zones and guide decisions about where to spend conservation funds or send armed rangers to protect animals, and it’s all thanks to the atomic crumbs left over from the Cold War. 

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Courtesy Murdoch University
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Animals
Australian Scientists Discover First New Species of Sunfish in 125 Years
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Courtesy Murdoch University

Scientists have pinpointed a whole new species of the largest bony fish in the world, the massive sunfish, as we learned from Smithsonian magazine. It's the first new species of sunfish proposed in more than 125 years.

As the researchers report in the Zoological Journal of the Linnean Society, the genetic differences between the newly named hoodwinker sunfish (Mola tecta) and its other sunfish brethren was confirmed by data on 27 different samples of the species collected over the course of three years. Since sunfish are so massive—the biggest can weigh as much as 5000 pounds—they pose a challenge to preserve and store, even for museums with large research collections. Lead author Marianne Nyegaard of Murdoch University in Australia traveled thousands of miles to find and collected genetic data on sunfish stranded on beaches. At one point, she was asked if she would be bringing her own crane to collect one.

Nyegaard also went back through scientific literature dating back to the 1500s, sorting through descriptions of sea monsters and mermen to see if any of the documentation sounded like observations of the hoodwinker. "We retraced the steps of early naturalists and taxonomists to understand how such a large fish could have evaded discovery all this time," she said in a press statement. "Overall, we felt science had been repeatedly tricked by this cheeky species, which is why we named it the 'hoodwinker.'"

Japanese researchers first detected genetic differences between previously known sunfish and a new, unknown species 10 years ago, and this confirms the existence of a whole different type from species like the Mola mola or Mola ramsayi.

Mola tecta looks a little different from other sunfish, with a more slender body. As it grows, it doesn't develop the protruding snout or bumps that other sunfish exhibit. Similarly to the others, though, it can reach a length of 8 feet or more. 

Based on the stomach contents of some of the specimens studied, the hoodwinker likely feeds on salps, a jellyfish-like creature that it probably chomps on (yes, sunfish have teeth) during deep dives. The species has been found near New Zealand, Australia, South Africa, and southern Chile.

[h/t Smithsonian]

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Space
Study Suggests There's Water Beneath the Moon's Surface
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Gregory H. Revera, Wikimedia Commons // CC BY-SA 3.0

Astronauts may not need to go far to find water outside Earth. As CNN reports, Brown University scientists Ralph E. Milliken and Shuai Li suspect there are significant amounts of water churning within the Moon’s interior.

Their findings, published in the journal Nature Geoscience, lean on the discovery of glass beads encased in the Moon’s volcanic rock deposits. As recently as 100 million years ago, the Earth’s moon was a hotbed of volcanic activity. Evidence of that volatile time can still be found in the ancient ash and volcanic rock that’s scattered across the surface.

Using satellite imagery, the researchers identified tiny water droplets preserved inside glass beads that formed in the volcanic deposits. While water makes up a small fraction of each bead, its presence suggests there’s significantly more of it making up the Moon’s mantle.

Milliken and Li aren't the first scientists to notice water in lunar rocks. In 2008, volcanic materials collected from the Moon during the Apollo missions of 1971 and 1972 were revealed to contain the same water-flecked glass beads that the Brown scientists made the basis of their recent study. They took their research further by analyzing images captured across the face of the Moon and quickly saw the Apollo rocks represented a larger trend. "The distribution of these water-rich deposits is the key thing," Milliken said in a press statement. "They're spread across the surface, which tells us that the water found in the Apollo samples isn't a one-off. Lunar pyroclastics seem to be universally water-rich, which suggests the same may be true of the mantle."

The study challenges what we know about the Moon's formation, which scientists think occurred when a planet-sized object slammed into the Earth 4.5 billion years ago. "The growing evidence for water inside the Moon suggests that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the Moon had completely solidified," Li said. "The exact origin of water in the lunar interior is still a big question."

The findings also hold exciting possibilities for the future of space travel. NASA scientists have already considered turning the Moon into a water station for astronauts on their way to Mars. If water on the celestial body is really as abundant as the evidence may suggest, figuring out how to access that resource will definitely be on NASA's agenda.

[h/t CNN]

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