A stash of stones uncovered in a prehistoric dwelling in Panama could be the earliest evidence of traditional healing, or shamanic practice, in lower Central America.
Archaeologists used radiocarbon dating of charcoal samples located directly above and below the stones to estimate that the stones were left in the dwelling sometime between 4,000 and 4,800 years ago. Since the stones were clustered together, the researchers say the collection was probably deposited in a container that has since decomposed.
Well, they’re not blueberries. That’s about as close as NASA comes to describing these bumps that the Opportunity rover has photographed from the Western rim of Mars’ Endeavor Crater. In 2004, soon after the rover arrived on the Red Planet, it encountered iron rich orbs (nicknamed blueberries) in the Victoria Cater that scientists cite as evidence for water in Mars’ past. After a preliminary analysis, the researchers found that these new Martian goosebumps, each about 3 millimeters wide, have a very different composition. In a press release, Opportunity’s principal investigator Steve Squyres described the newfound formations as “crunchy on the outside, and softer in the middle” and said that they are considering multiple hypotheses about what these bumps might mean. For now, however, how they were formed—and what they might reveal—remains a mystery.
Image courtesy of NASA/JPL-Caltech/Cornell Univ./ USGS/Modesto Junior College
The excavation at Spitalfields
The churchyard at St. Mary’s in Spitalfields, London, was the final resting place for more than 10,000 people in medieval times. But among the run-of-the-mill gravesites, archaeologists with the Museum of London Archaeology have found, were 175 mass graves, containing the closely packed bodies of thousands of men, women, and children. What happened to these people? The answer, it turns out, could be decidedly unusual.
The team’s first thought was the obvious: the Black Death, which ravaged England starting in 1347. But once the bodies in the mass graves were carbon dated, it was clear that they had died a hundred years before the first plague-carrying flea came to Britain: around 1250. “As soon as we got the radiocarbon dates back, we knew that couldn’t possibly be the case. There had to be some other event,” says Natasha Powers, the head of osteology at the Museum of London Archaeology.
Cassini image of a landslide on Iapetus
Landslides can wreak enormous destruction, especially when they travel farther than expected. When an avalanche occurs, dirt both falls vertically and spreads horizontally, with the horizontal distance usually no more than twice the vertical drop. But in a sturzstrom, some unknown factor decreases the coefficient of friction, allowing the earth to slide much farther; it acts more like a glacier or a lava flow than a regular avalanche. Theories about that friction-reducing factor abound—trapped air, water, or mud, pressure, rubbed and heated rock becoming more slippery, rock nanoparticles, sound waves, changes in local gravity—but its true nature is still unknown. By examining sturzstroms that occur on distant planets and moons—whose forces of gravity, atmospheres, fluids, and soil differ from those on Earth—researchers hope to unravel the factors that contribute to a landslide’s length. This information could help us predict landslides’ shapes and alleviate the damage they cause.
Mount St. Helens eruption in 1980
Step aside, crystal balls—another kind of crystal could help scientists forecast eruptions. The structure of microscopic crystals in lava oozing out of volcanoes give clues into when and how a volcano will erupt, according to a study on Mount St. Helens just published in Science.
For six years after Mount St. Helens infamously blew its top in 1980, the volcano in Washington continued to spew and sputter, erupting periodically. Each eruption brought more magma to the surface, and crystals embedded in the magma are snapshots of what happened inside the volcano just before each eruption. They contain concentric circles of elements like iron and magnesium, just like tree rings. Volcanologists examined over 300 of these crystals from Mount St. Helens, each no more than 1/10 of a millimeter in size.
Mercury is an odd little planet, tiny but incredibly dense, relatively close by but hard to study via telescope. The MESSENGER probe‘s latest findings, 57 papers presented two days ago at conference, bring new weirdness to our understanding of the planet closest to the Sun.
Take, for instance, the new revelations about Mercury’s core. We always knew that Mercury had a proportionally larger core than Earth does; geologists thought that it might make up a whopping 42% of the planet’s volume, in comparison to Earth’s 17%. The newest estimate, though, blows that out of the water: We now think the number is 85%. To boot, there appears to be an extremely dense layer more than a hundred miles thick encasing the core, perhaps a shell of iron sulfide. That makes the mantle and crust—to use the memorable analogy of a planetary scientist interviewed by Wired—like a mere orange peel on a giant orange of metal.
Another memorable finding: the largest crater on Mercury, Caloris Basin, isn’t actually much of a basin. It seems that the crater’s center gradually rose at some point in the not-too-distant past until it was higher than its edges. This has geologists revising their impressions that Mercury stopped being geologically active 4.5 billion years ago to something more like 2 billion years ago.
Image courtesy of Case Western Reserve University
Pulling together decades of data from the Voyager, Galileo, Cassini, and New Horizon probes, as well as the Hubble Space Telescope, scientists at the US Geological Survey have put together a complete geological map of Io, the beautiful, mysterious Jovian moon. Io is the most volcanically active object in the solar system, and its surface reflects that: unlike everything else around, it has no craters, a sign that its surface is constantly being remade. That’s thanks to volcanoes that shoot out more than 100 times more lava per year than Earth’s.
The map is a lovely thing, and you can play around with it yourself here.
Geological analysis suggest the current-day continents we know and love will drift together, forming a new supercontinent like ones that existed many millions of years ago. What’s not certain is where that supercontinent will be. The authors of a new Nature study suggest that the next supercontinent, dubbed Amasia, will join together up in the Arctic. Antarctica, though, would stay by its lonesome in the south.
Artist’s rendering of AVIATR flying on Titan.
Saturn’s moon Titan is a lot like Earth: it has rain, seasons, volcanoes, and maybe even life. Well, it’s not exactly like Earth: the rain is liquid methane, the volcanoes spew ice, and any life would be based on methane. But still, it’s an interesting and relatively Earth-like place, considering the other planets and moons in our solar system. And University of Idaho physicist Jason Barnes says he has a perfect way to explore this moon: with a flying drone.
Why use a flying machine rather than the rovers that worked so well on Mars? With 1/7 the gravity but 4 times the atmospheric density of Earth, flying through Titan is 28 times easier than on our own planet. In fact, it’s the easiest place to fly in our entire solar system. Drones on Titan can be heavier while requiring less fuel. With these facts in hand, University of Idaho physicist Jason Barnes has proposed AVIATR, otherwise known as the Aerial Vehicle for In-situ and Airborne Titan Reconnaissance.
If you could watch a movie of the planet over the last several million years, you’d see the ice caps advance and retreat: The planet’s climate moves in cycles, with ice ages and interglacial periods alternating. But looking at previous interglacials similar to our own, geophysicists now think that the current mostly ice-less period may be longer than it would have been had a certain species not invented the combustion engine. Specifically, it looks like with amount of greenhouse gases we’ve already spewed into the atmosphere, the next ice age will be delayed. And before you decide that’s a good thing, at the rate we’re currently going, we’re not just pushing off the glaciers for a few geologically insignificant years: the team says that the atmospheric concentration of CO2 would to be at most 240 parts per million (ppm) before glaciation would kick in. Right now, it’s 390 ppm, with no signs of dropping and many signs of continuing to rise. When (and how) the planet’s self-regulation system will kick in isn’t clear, but the long, increasingly hot trip probably isn’t going to be pretty.
Read more at the BBC.
Image courtesy of NASA / Wikipedia