пятница, 7 декабря 2018 г.

New study upends timeline of Iroquoian history

New research by an international team raises questions about the timing and nature of early interactions between indigenous people and Europeans in North America.











New study upends timeline of Iroquoian history
A human face effigy from ceramic vessel from the Mantle site
[Credit: Archaeological Services Inc./Andrea Carnevale]

The European side of first contact with indigenous people and settlement in northeast North America is well known from European sources. Until now it’s been assumed that the finds of dated European artifacts provide a timeline for the indigenous peoples and settlements of this period as well. New research suggests this may be a mistake in cases where there was not direct and intensive exchange.


Radiocarbon dating and tree-ring evidence shows that three major indigenous sites in Ontario, Canada, conventionally dated 1450-1550 are in fact 50-100 years more recent. This dates the sites to the worst period of the Little Ice Age, around 1600.


“This seems extraordinary: Given this was only 400 years ago, how can we have been wrong by as much as 25 percent?” said first author Sturt Manning, the Goldwin Smith Professor of Classical Archaeology, chair of the Department of Classics and director of the Cornell Tree-Ring Laboratory.


Manning is lead author of “Radiocarbon Re-dating of Contact-era Iroquoian History in Northeastern North America,” published in Science Advances. Other Cornell authors include Cornell Tree-Ring Laboratory senior researcher Carol Griggs ’77, Ph.D. ’06, and doctoral student Samantha Sanft. The paper represents the first major findings of the “Dating Iroquoia” project, a National Science Foundation-funded effort led by Manning and co-director Jennifer Birch (University of Georgia).


Previously, dates in the early contact period were based on the absence – and then presence – of types of glass beads and other European trade goods in excavated sites, along with shifts in material culture, such as changes in ceramic designs. Dates were assigned according to “time transgression,” the assumption that when European goods are found in one place with a confirmed date associated with them, that same date can be used for other places where those trade goods are found.


“But goods don’t get distributed evenly within societies or across distances,” said Manning. “This is a vast area with complex local societies and economies, so the concept that everybody gets the same thing necessarily all at once is a bit ludicrous in retrospect.”


The team’s chronological findings dramatically rewrite how history has been understood in the region. The period of first European contact, rather than following major changes in Iroquoian society, can now be seen to coincide with those changes. According to Birch, an expert on Iroquoian societies, “Our work has shown that, at least for some communities, contact-era transformations happened much later and much more rapidly than previously assumed.”


“Of course, we’ve dated only one site sequence, and there are many more,” Manning said. “What this paper really shows is we now need to reassess all those site sequences where there’s not a clear historical link or association.”


The researchers first examined the Warminster site in Canada, believed to be visited by French explorer Samuel de Champlain in 1615. Using radiocarbon isotope and dendrochronological (tree ring) dating, combined with a mathematical technique, determined the indigenous settlement at the location to date from between 1585 and 1624, which corresponded with Champlain’s visit. Archaeological evidence and provided confirmation of the accuracy of their techniques.


The team then assessed a series of well-known, high profile settlements, Draper-Spang-Mantle. In the 16th century, Iroquoian societies lived in village communities for approximately 10 to 50 years; once the local resources were exhausted, the community relocated the village. Archaeological evidence indicates that these three villages were occupied in sequence by the same ancestral Huron-Wendat community. Mantle, the latest site in the sequence, was shown to date to between 1599 and 1614, partly contemporaneously with Warminster.


Author: Linda B. Glaser | Source: Cornell University [December 05, 2018]



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A detailed look at the microorganisms that colonize, and degrade, a 400-year-old painting

What’s a feast for the human eye may be a literal feast for microorganisms that colonize works of art, according to a new study in the open-access journal PLOS ONE by Elisabetta Caselli of the University of Ferrara, Italy, and colleagues. The researchers characterized the microbial community on a 17th century painting and showed that while some microbes destroy such works of art, others might be employed to protect them.











A detailed look at the microorganisms that colonize, and degrade, a 400-year-old painting
Carlo Bononi, Incoronazione della Vergine: 1616-1620, oil on canvas, 280 cm in diameter, Ferrara, Basilica of Santa
Maria in Vado: a) painting (sampling points are indicated by asterisks, *); b) damage due to biodegradation (verso);
c) craquelures network; d) lacerations, deformations, and gaps corresponding to the cloth stitching (recto).
Details of the damage are reported on the side [Credit: MuseoinVita biannual journal, 2018]

The wide variety of organic and inorganic materials that comprise a painting, such as canvas, oil, pigments, and varnish, can provide an ideal environment for colonizing bacteria and fungi, increasing the risk for biodegradation. To characterize the microorganisms on one such painting, “Incoronazione della Virgine” by Carlo Bononi, completed in 1620, the authors removed a 4 mm2 section of the painted surface adjacent to a damaged area.
Using a combination of microscopy and microbial culture techniques, the authors identified a variety of microbes which had colonized the painting. They isolated multiple strains of Staphylococcus and Bacillus bacteria as well as filamentous fungi of the Aspergillus, Penicillium, Cladosporium, and Alternaria genera.











A detailed look at the microorganisms that colonize, and degrade, a 400-year-old painting
Bacteria detected on the painting: Samples were collected from the recto (a, b, c) and the verso (d, e, f) of the painting.
a) colonies of Staphylococcus spp. on a Mego agar plate; b) the same Staphylococcus spp. viewed by OM after
Gram staining (original magnification 100X) and c) by SEM. d) colonies of Bacillus spp. on a TSA agar plate;
e) the same Bacillus spp. viewed by OM after Gram staining (original magnification 100X) and f) SEM
[Credit: Caselli et al., 2018]

The authors note that some of the 17th century paint pigments used, notably red lac and red and yellow earths, may be nutrient sources for the microbes. They also tested a decontaminating biocompound which contained spores of three Bacillus bacteria and found that these could inhibit growth of both the bacteria and the fungi isolated from the painting.
The authors conclude that a wide range of bacterial and fungal species may inhabit such ancient paintings, but biocompounds potentially represent a novel approach for preserving works of art at risk of biodegradation.


The authors add: “Clarification of biotederioration processes in artworks is important, as it could help in preventing or solving the associated damages. This study investigated such aspects in a 17th century painting, by analyzing both microbial communities and chemical composition of painting, also evaluating a possible biological way to counteract these phenomena.”


Source: PLOS [December 05, 2018]



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An exoplanet loses its atmosphere in the form of a tail

Although helium is a rare element on Earth, it is ubiquitous in the Universe. It is, after hydrogen, the main component of stars and gaseous giant planets. Despite its abundance, helium was only detected recently in the atmosphere of a gaseous giant by an international team including astronomers from the University of Geneva (UNIGE), Switzerland. The team, this time led by Genevan researchers, has observed in detail and for the first time how this gas escapes from the overheated atmosphere of an exoplanet, literally inflated with helium. The results are published in Science.











An exoplanet loses its atmosphere in the form of a tail
Evaporation of atmopheric helium on the giant exoplanet WASP-69b
[Credit: Gabriel Perez Diaz, SMM (IAC)]

Helium is the second most abundant element in the Universe. Predicted since 2000 as one of the best possible tracers of the atmospheres of exoplanets, these planets orbiting around other stars than the Sun, it took astronomers 18 years to actually detect it. It was hard to spot due to the very peculiar observational signature of helium, located in the infrared, out of range for most of the instruments used previously.
The discovery occurred earlier this year, thanks to Hubble Space Telescope observations, which proved difficult to interpret. Team members from UNIGE, members of the National Centre for Competence in Research PlanetS, had the idea of pointing another telescope equipped with a brand-new instrument — a spectrograph called Carmenes.


Detecting colours of planets with Carmenes


A spectrograph decomposes the light of a star into its component colours, like a rainbow. The “resolution” of a spectrograph is a measure indicating the number of colours that can be revealed. While the human eye cannot distinguish any colour beyond red without an adapted camera, the infrared eye of Hubble is capable of identifying hundreds of colours there. This proved sufficient to identify the coloured signature of helium. The instrument Carmenes, installed on the 4-metre telescope at the observatory of Calar Alto in Andalusia, Spain, is capable to identify more than 100’000 colours in the infrared!



This high spectral resolution allowed the team to observe the position and speed of helium atoms in the upper atmosphere of a gaseous Neptune-size exoplanet, 4 times larger than the Earth. Located in the Cygnus (the Swan) constellation, 124 light-years from home, HAT-P-11b is a “warm Neptune” (a decent 550°C!), twenty times closer to its star than the Earth from the Sun.
“We suspected that this proximity with the star could impact the atmosphere of this exoplanet” says Romain Allart, PhD student at UNIGE and first author of the study. “The new observations are so precise that the exoplanet atmosphere is undoubtedly inflated by the stellar radiation and escapes to space,” he adds.


A planet inflated with helium


These observations are supported by numerical simulation, led by Vincent Bourrier, co-author of the study and member of the European project FOUR ACES. Thanks to the simulation, it is possible to track the trajectory of helium atoms: “helium is blown away from the day side of the planet to its night side at over 10’000 km/h,” Vincent Bourrier explains. “Because it is such a light gas, it escapes easily from the attraction of the planet and forms an extended cloud all around it.” This gives HAT-P-11b the shape of a helium-inflated balloon.


This result opens a new window to observe the extreme atmospheric conditions prevailing in the hottest exoplanets. The Carmenes observations demonstrate that such studies, long thought feasible only from space, can be achieved with greater precision by ground-based telescopes equipped with the right kind of instruments. “These are exciting times for the search of atmospheric signatures in exoplanets,” says Christophe Lovis, senior lecturer at UNIGE and co-author of the study.


In fact, UNIGE astronomers are also heavily involved in the design and exploitation of two new high-resolution infrared spectrographs, similar to Carmenes. One of them, called SPIRou, has just started an observational campaign from Hawaii, while the UNIGE Department of astronomy houses the first tests of the Near Infrared Planet Searcher (NIRPS), which will be installed in Chile at the end of 2019.


“This result will enhance the interest of the scientific community for these instruments. Their number and their geographical distribution will allow us to cover the entire sky, in search for evaporating exoplanets,” concludes Lovis.


Source: Université de Genève [December 06, 2018]




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Russian scientists found new giant dinosaur

Paleontologists from Russia have described a new dinosaur, the Volgatitan. Seven of its vertebrae, which had remained in the ground for about 130 million years, were found on the banks of the Volga, not far from the village of Slantsevy Rudnik, five kilometers from Ulyanovsk. The study has been published in the latest issue of Biological Communications.











Russian scientists found new giant dinosaur
Volgatitan simbirskiensis anterior caudal vertebra (holotype), in right lateral (A), anterior (B),
left lateral (C), posterior (D), dorsal (E), and ventral (F) views
[Credit: Alexander Averianov and Vladimir Efimov]

The Volgatitan belongs to the group of sauropods – giant herbivorous dinosaurs with a long neck and tail, who lived on Earth about 200 to 65 million years ago. Weighing around 17 tons, the ancient reptile from the banks of the Volga was not the largest among its relatives. The scientists described it from seven caudal vertebrae. The bones belonged to an adult dinosaur which is manifested by neural arches (parts of the vertebrae protecting the nerves and blood vessels), which completely merged with the bodies of the vertebrae.
The remains of the dinosaur were discovered near the village of Slantsevy Rudnik. This is where, in 1982, Vladimir Efimov discovered three large vertebrae that had fallen out of a high cliff. Later, in 1984-1987, three nodules of limestone fell off, which contained the remaining vertebrae. In his works, the head of the Undorovsky Paleontology Museum called the unusual finds “giant vertebrae of unknown taxonomic affiliation”.


“In the early 1990s, Vladimir Efimov showed photographs of the bones to Lev Nesov, a well-known Leningrad paleontologist,” recollected Alexander Averianov. Lev Nesov thought that the vertebrae belonged to sauropods, giant herbivorous dinosaurs. In 1997, Vladimir Efimov published a preliminary note about this find in the Paleontological Journal. He referred to the vertebrae as a sauropod of the Brachiosauridae family. Last July, I finally managed to visit him in Undory and study the bones, and also managed to determine that they belonged to the new taxon of titanosaurs.”


The dinosaur received a scientific name – Volgatitan simbirskiensis. It comes from the Volga River and the city of Simbirsk (currently, Ulyanovsk). Titans are ancient Greek gods known for their large size. Therefore, according to a paleontological tradition, this word is used in many scientific names of sauropods from the group of titanosaurs. It is also part of the name of the group.


Today, along with the Volgatitan from Russia, 12 valid dinosaur taxa have already been described. There are only three sauropods among them: Tengrisaurus starkovi, Sibirotitan astrosacralis and Volgatitan simbirskiensis. The first two are the first sauropods in Russia, which were also studied by St Petersburg University scientists in 2017. According to Aleksandr Averianov, the description of dinosaur taxa in recent years has become possible due to the progress in understanding the anatomy and phylogeny of dinosaurs. In addition, the Russian sauropod allowed scientists to learn more about how these species of ancient reptiles had lived and developed.


“Previously, it was believed that the evolution of titanosaurs took place mainly in South America with some taxa moving into North America, Europe and Asia only in the Late Cretaceous,” explained the St Petersburg University professor. In Asia, representatives of a broader group of titanosauriform, such as the recently described Siberian titanium, dominated in the early Cretaceous. However, the recent description of the Tengrisaurus from the Early Cretaceous of Transbaikal Region and the finding of the Volgatitan indicate that titanosaurs in the Early Cretaceous were distributed much more widely; and, perhaps, important stages of their evolution took place in Eastern Europe and Asia.”


Source: Akson Russian Science Communication Association [December 06, 2018]



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Biggest mass extinction caused by global warming leaving ocean animals gasping for breath

The largest extinction in Earth’s history marked the end of the Permian period, some 252 million years ago. Long before dinosaurs, our planet was populated with plants and animals that were mostly obliterated after a series of massive volcanic eruptions in Siberia.











Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
This illustration shows the percentage of marine animals that went extinct at the end of the Permian era by latitude, from
the model (black line) and from the fossil record (blue dots). A greater percentage of marine animals survived in the tropics
than at the poles. The color of the water shows the temperature change, with red being most severe warming and yellow
less warming. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide.
The images below the line represent some of the 96 percent of marine species that died during the event. Includes
 fossil drawings by Ernst Haeckel/Wikimedia; Blue crab photo by Wendy Kaveney/Flickr; Atlantic cod photo by
Hans-Petter Fjeld/Wikimedia; Chambered nautilus photo by ©2010 John White/CalPhotos
[Credit: Justin Penn and Curtis Deutsch/University of Washington]

Fossils in ancient seafloor rocks display a thriving and diverse marine ecosystem, then a swath of corpses. Some 96 percent of marine species were wiped out during the “Great Dying,” followed by millions of years when life had to multiply and diversify once more.


What has been debated until now is exactly what made the oceans inhospitable to life – the high acidity of the water, metal and sulfide poisoning, a complete lack of oxygen, or simply higher temperatures.


New research from the University of Washington and Stanford University combines models of ocean conditions and animal metabolism with published lab data and paleoceanographic records to show that the Permian mass extinction in the oceans was caused by global warming that left animals unable to breathe. As temperatures rose and the metabolism of marine animals sped up, the warmer waters could not hold enough oxygen for them to survive.


“This is the first time that we have made a mechanistic prediction about what caused the extinction that can be directly tested with the fossil record, which then allows us to make predictions about the causes of extinction in the future,” said first author Justin Penn, a UW doctoral student in oceanography.











Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
This fossilized spiraling shark tooth is from the Helicoprion, an unusual shark that lived during the Permian. The tooth
whorl was located inside the shark’s lower jaw. The fossil is on display at the Idaho Museum of Natural History
[Credit: James St. John/Flickr]

Researchers ran a climate model with Earth’s configuration during the Permian, when the land masses were combined in the supercontinent of Pangaea. Before ongoing volcanic eruptions in Siberia created a greenhouse-gas planet, oceans had temperatures and oxygen levels similar to today’s. The researchers then raised greenhouse gases in the model to the level required to make tropical ocean temperatures at the surface some 10 degrees Celsius (20 degrees Fahrenheit) higher, matching conditions at that time.


The model reproduces the resulting dramatic changes in the oceans. Oceans lost about 80 percent of their oxygen. About half the oceans’ seafloor, mostly at deeper depths, became completely oxygen-free.


To analyze the effects on marine species, the researchers considered the varying oxygen and temperature sensitivities of 61 modern marine species — including crustaceans, fish, shellfish, corals and sharks — using published lab measurements. The tolerance of modern animals to high temperature and low oxygen is expected to be similar to Permian animals because they had evolved under similar environmental conditions. The researchers then combined the species’ traits with the paleoclimate simulations to predict the geography of the extinction.


“Very few marine organisms stayed in the same habitats they were living in — it was either flee or perish,” said second author Curtis Deutsch, a UW associate professor of oceanography.











Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
A fossil from Morocco of a Diademaproetus, one of the trilobites that were plentiful in the world’s oceans
but went extinct at the end of the Permian [Credit: Géry Parent/Flickr]

The model shows the hardest hit were organisms most sensitive to oxygen found far from the tropics. Many species that lived in the tropics also went extinct in the model, but it predicts that high-latitude species, especially those with high oxygen demands, were nearly completely wiped out.


To test this prediction, co-authors Jonathan Payne and Erik Sperling at Stanford analyzed late-Permian fossil distributions from the Paleoceanography Database, a virtual archive of published fossil collections. The fossil record shows where species were before the extinction, and which were wiped out completely or restricted to a fraction of their former habitat.


The fossil record confirms that species far from the equator suffered most during the event.


“The signature of that kill mechanism, climate warming and oxygen loss, is this geographic pattern that’s predicted by the model and then discovered in the fossils,” Penn said. “The agreement between the two indicates this mechanism of climate warming and oxygen loss was a primary cause of the extinction.”











Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
A fossil of a Paramblypterus, a species of fish that went extinct during the Permian. This fossil is on display
at the State Museum of Natural History in Karlsruhe, Germany [Credit: H. Zell/WikiCommons]

The study builds on previous work led by Deutsch showing that as oceans warm, marine animals’ metabolism speeds up, meaning they require more oxygen, while warmer water holds less. That earlier study shows how warmer oceans push animals away from the tropics.


The new study combines the changing ocean conditions with various animals’ metabolic needs at different temperatures. Results show that the most severe effects of oxygen deprivation are for species living near the poles.


“Since tropical organisms’ metabolisms were already adapted to fairly warm, lower-oxygen conditions, they could move away from the tropics and find the same conditions somewhere else,” Deutsch said. “But if an organism was adapted for a cold, oxygen-rich environment, then those conditions ceased to exist in the shallow oceans.”


The so-called “dead zones” that are completely devoid of oxygen were mostly below depths where species were living, and played a smaller role in the survival rates. “At the end of the day, it turned out that the size of the dead zones really doesn’t seem to be the key thing for the extinction,” Deutsch said. “We often think about anoxia, the complete lack of oxygen, as the condition you need to get widespread uninhabitability. But when you look at the tolerance for low oxygen, most organisms can be excluded from seawater at oxygen levels that aren’t anywhere close to anoxic.”











Biggest mass extinction caused by global warming leaving ocean animals gasping for breath
This roughly 1.5-foot slab of rock from southern China shows the Permian-Triassic boundary. The bottom section
is pre-extinction limestone. The upper section is microbial limestone deposited after the extinction
[Credit: Jonathan Payne/Stanford University]

Warming leading to insufficient oxygen explains more than half of the marine diversity losses. The authors say that other changes, such as acidification or shifts in the productivity of photosynthetic organisms, likely acted as additional causes.


The situation in the late Permian — increasing greenhouse gases in the atmosphere that create warmer temperatures on Earth — is similar to today.


“Under a business-as-usual emissions scenarios, by 2100 warming in the upper ocean will have approached 20 percent of warming in the late Permian, and by the year 2300 it will reach between 35 and 50 percent,” Penn said. “This study highlights the potential for a mass extinction arising from a similar mechanism under anthropogenic climate change.”


The study is published in the journal Science.


Author: Hannah Hickey | Source: University of Washington [December 06, 2018]



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An ancient strain of plague may have led to the decline of Neolithic Europeans

A team of researchers from France, Sweden, and Denmark have identified a new strain of Yersinia pestis, the bacteria that causes plague, in DNA extracted from 5,000-year-old human remains. Their analyses, published in the journal Cell, suggest that this strain is the closest ever identified to the genetic origin of plague. Their work also suggests that plague may have been spread among Neolithic European settlements by traders, contributing to the settlements’ decline at the dawn of the Bronze Age.











An ancient strain of plague may have led to the decline of Neolithic Europeans
The remains of a 20-year old woman (Gokhem2) from around 4900 BP that was killed
by the first plague pandemic. She was one of the victims of a plague pandemic
 that likely lead to the decline of the Neolithic societies in Europe
[Credit: Karl-Göran Sjögren/University of Gothenburg]

“Plague is maybe one of the deadliest bacteria that has ever existed for humans. And if you think of the word ‘plague,’ it can mean this infection by Y. pestis, but because of the trauma plague has caused in our history, it’s also come to refer more generally to any epidemic. The kind of analyses we do here let us go back through time and look at how this pathogen that’s had such a huge effect on us evolved,” says senior author Simon Rasmussen, a metagenomics researcher at the Technical University of Denmark and the University of Copenhagen.


To better understand the evolutionary history of the plague, Rasmussen and his colleagues trawled through publicly available genetic data from ancient humans, screening for sequences similar to more modern plague strains. They found a strain they had never seen before in the genetic material of a 20-year-old woman who died approximately 5,000 years ago in Sweden. The strain had the same genes that make the pneumonic plague deadly today and traces of it were also found in another individual at the same grave site — suggesting that the young woman did likely die of the disease.


This strain of the plague is the oldest that’s ever been discovered. But what makes it particularly interesting is that, by comparing it to other strains, the researchers were able to determine that it’s also the most basal — meaning that it’s the closest strain we have to the genetic origin of Y. pestis. It likely diverged from other strains around 5,700 years ago, while the plague that was common in the Bronze Age and the plague that is the ancestor of the strains in existence today diverged 5,300 and 5,100 years ago, respectively. This suggests that there were multiple strains of plague in existence at the end of the Neolithic period.


Rasmussen also believes that this finding offers a new theory about how plague spreads. Massive human migrations from the Eurasian steppe down into Europe are known to have occurred around 5,000 years ago, but how these cultures were able to displace the Neolithic farming culture that was present in Europe at the time is still debated. Previous researchers have suggested that the invaders brought the plague with them, wiping out the large settlements of Stone Age farmers when they arrived.











An ancient strain of plague may have led to the decline of Neolithic Europeans
How researchers believe the plague spread [Credit: Gothenburg University]

But if the strain of plague the researchers found in the Swedish woman diverged from the rest of Y. pestis 5,700 years ago, that means it likely evolved before these migrations began and around the time that the Neolithic European settlements were already starting to collapse.


At the time, mega-settlements of 10,000-20,000 inhabitants were becoming common in Europe, which made job specialization, new technology, and trade possible. But they also may have been the breeding ground for plague. “These mega-settlements were the largest settlements in Europe at that time, ten times bigger than anything else. They had people, animals, and stored food close together, and, likely, very poor sanitation. That’s the textbook example of what you need to evolve new pathogens,” says Rasmussen.


“We think our data fit. If plague evolved in the mega-settlements, then when people started dying from it, the settlements would have been abandoned and destroyed. This is exactly what was observed in these settlements after 5,500 years ago. Plague would also have started migrating along all the trade routes made possible by wheeled transport, which had rapidly expanded throughout Europe in this period,” he says.


Eventually, he suggests, the plague would have arrived through these trade interactions at the small settlement in Sweden where the woman his team studied lived. Rasmussen argues that the woman’s own DNA also provides further evidence for this theory — she isn’t genetically related to the people who invaded Europe from the Eurasian steppe, supporting the idea that this strain of plague arrived before the mass migrations did. The archaeology also supports this hypothesis, as there were still no signs of the invaders by the time she died.











An ancient strain of plague may have led to the decline of Neolithic Europeans
Some of the remains examined [Credit: Karl-Göran Sjögren/
University of Gothenburg]

Of course, there are some limitations to what the data from this study can tell us. Most importantly, the researchers have not yet identified the plague in individuals from the mega-settlements where it may have evolved. “We haven’t really found the smoking gun, but it’s partly because we haven’t looked yet. And we’d really like to do that, because if we could find plague in those settlements, that would be strong support for this theory,” says Rasmussen.
Regardless, he believes that this study is a step toward understanding how plague — and other pathogens — became deadly. “We often think that these superpathogens have always been around, but that’s not the case,” he says. “Plague evolved from an organism that was relatively harmless. More recently, the same thing happened with smallpox, malaria, Ebola, and Zika. This process is very dynamic — and it keeps happening. I think it’s really interesting to try to understand how we go from something harmless to something extremely virulent.”


Source: Cell Press [December 06, 2018]



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Three Minute Warning A lot can happen in three minutes. You…


Three Minute Warning


A lot can happen in three minutes. You could boil an egg, walk a few hundred metres, or have a quick argument on social media. For a newly-fertilised fruit fly embryo, the first three minutes of development are probably the most important of its entire life. A fly egg is packed with all sorts of useful molecules known as morphogens, laid down in precise patterns that determine important aspects of the embryo such as which end is the head and which is the tail. As soon as the egg is fertilised, the morphogens spring into action and start switching on genes that begin the process of development in a matter of minutes. These images represent data from a new real-time imaging technique that captures this frenzy of gene activity as coloured spots, shown in a healthy embryo (top) and two others with faults in an important developmental gene called Zelda.


Written by Kat Arney



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Viewing the Geminid Meteor Shower in 2018

Year in and year out the Geminids are currently the most dependable meteor shower. Unfortunately, they are active in December when temperatures are often cold and skies cloudy in the northern hemisphere. If this shower peaked in August it would be much more popular, but the radiant would then lie much closer to the sun and Geminid meteors would only be visible in the few hours preceding dawn.


These meteors are visible over the entire northern hemisphere and the southern hemisphere down to where it remains light around the clock. The best vantage point lies along the 30th parallel of north latitude, where the radiant passes overhead, usually between 01:00 and 02:00. There is not much change in rates the further north you go until you reach the polar regions. In the southern hemisphere rates fall precipitously the further south you are located due to the lower elevation of the radiant in the northern sky.



In December, the Geminid radiant lies nearly opposite the sun. Therefore, Geminid meteors are visible all night long from the northern hemisphere. In the southern hemisphere the radiant rises much later and is only above the horizon for a limited time (depending on your exact latitude) before the break of dawn.


The Geminids seen during the early evening hours are long and slow moving. The reason for this is that the Earth is just beginning to face toward the incoming meteors. They are just able to skim the upper portions of the atmosphere so they last longer in the thinner air and tend to create long paths in the sky. As the night progresses the Earth turns more directly toward Gemini and the meteors strike the atmosphere more directly creating shorter and quicker meteors, at least to our eyes. In fact, the Geminid meteors strike the Earth with the same velocity no matter what time it is. It’s our perspective from the ground that makes it seems that they change speeds and lengths.


Composite of Geminid Meteors – Dec, 14th, 2015 © Antoni Cladera / Photopills.com
Nikon D4s, 14mm, f2.8, 30s, 5000 ISO

The Geminids are produced by the comet/asteroid known as 3200 Phaethon. This object is classified as an Apollo asteroid but often acts like a comet by ejecting dust when it nears the sun. The Earth is near the orbit of 3200 Phaethon during the first three weeks of December. It comes closest to the core of the orbit on December 14th each year. This is the date most Geminid meteors are encountered and seen. When the Earth is near the edge of the orbital debris of the asteroid, little activity is seen. Unlike most meteor showers, the activity curve is asymmetrical. The climb to maximum activity is slower than the fall. Geminid activity is impressive for several nights prior to maximum but drops off quickly after December 14th.



To best seen the Geminids you need to view as close to December 14th as possible. In 2018, the waxing crescent moon will be present in the evening sky. Geminid meteors can be seen with the moon in the sky but it is advised to keep your back to the bright moon so that your eyes can adjust to the darkness. Like all meteors showers, there are many more faint meteors than bright ones. Eyes that had just stared at the moon or just came outside from indoors will not be able to see these fainter meteors. Give your eyes time at adjust to the darkness. It is also advisable to watch for as long as possible as meteor activity waxes and wanes throughout the night. There will be periods when little activity is seen and then other periods when meteors are falling constantly. These periods often last as long as 15 minutes so it is advisable to watch for an hour or more so that you witness several peaks and valleys and get a real feel of the meteor activity.


Radar images of near-Earth asteroid 3200 Phaethon generated by astronomers at the Arecibo Observatory on December 17, 2017. The 2017 encounter was the closest the asteroid will come to Earth until 2093.

In order to view for that long, you need to be comfortable so a lounge chair is recommended. Lie back and view at a 45 degree (halfway up) angle to see the most activity. In the northern hemisphere be sure to have a blanket or two as December nights can be frosty. You can face in any direction as Geminid meteors can be seen in any part of the sky. No matter what part of the sky they appear, they will all trace back to the radiant near the bright star known as Castor (alpha Geminorum). As stated before, if the moon is above the horizon, keep it out of your field of view. You don’t have to know where Castor is located, but you will soon learn as meteor after meteor will shoot forth from that direction. Another item you will discover is that not all meteors will be Geminids. You will see some meteors, both faster and slower than Geminids, travel toward Gemini and in many other directions. Most of these will be random meteors that don’t belong to any recognizable shower. Some of the others will belong to minor showers that produce only a few meteors per hour.


It’s interesting and scientifically useful to categorize these meteors and total the hourly rates you witness from each source. You can share your results by filling out a meteor report form on the website of the International Meteor Organization (IMO) located here: VMDB


Lastly, you may wish to try and photograph the meteor activity. The Geminids are perfect subjects as the brightest meteors are often colorful and their slower speed allows more light to be recorded. You simply need a camera that can take time exposures in the range of 1 to 10 minutes. The darker the sky, the longer the exposure can be without being washed out. Stars will be pinpoints in short exposures but will trail across the frame in parallel paths in exposures exceeding a minute. Meteors will appear as straight streaks across your frame often crossing star trails.


We hope you will attempt to view the Geminids, one of nature’s best light shows. We encourage all observers, regardless of experience, to share their observations with us!


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Learning from lunar lights


Asteroid Watch logo.


7 December 2018


Every few hours observing the Moon, ESA’s ‘NELIOTA’ project discovers a brilliant flash of light across its surface – the result of an object hurtling through space and striking our unprotected rocky neighbour at vast speed. Based at the Kryoneri telescope of the National Observatory of Athens, this important project is now being extended to January 2021.



Lunar impact Gif

From the Moon’s past, to Earth’s home


Impact flashes are referred to as ‘transient lunar phenomena’, because although common, they are fleeting occurrences, lasting just fractions of a second. This makes them difficult to study, and because the objects that cause them are too small to see, impossible to predict.


For this reason scientists are studying lunar flashes with great interest, not only for what they can tell us about the Moon and its history, but also about Earth and its future.



SMART-1 view of Shackleton crater at lunar South Pole

By observing lunar impacts, NELIOTA (NEO Lunar Impacts and Optical TrAnsients) aims to determine the size and distribution of near-Earth objects (NEOs) – meteoroids, asteroids or comets. With this information, the risk these space rocks pose to Earth can be better understood.


The world’s largest eye on the Moon


In February 2017, a 22-month campaign began to observe lunar flashes with the 1.2 metre Kryoneri telescope, the largest telescope on Earth to monitor the Moon.


The flashes of light caused by lunar impacts are far dimmer than the sunlight reflected off the Moon. For this reason, we can only observe these impacts on the Moon’s ‘dark side’ – between New Moon and First Quarter, and between Last Quarter and New Moon. The Moon must also be above the horizon, and observations require a fast-frame camera, such as the Andor Zyla sCMOS used in the NELIOTA project.



The Kryoneri Observatory – the world’s largest eye on the Moon

To date, in the 90 hours of possible observation time that these factors allowed, 55 lunar impact events have been observed. Extrapolating from this data, scientists estimate that there are, on average, almost 8 flashes per hour across the entire surface of the Moon. With the extension of this observing campaign to 2021, further data should improve impact statistics.



Locations of lunar impact flashes detected by the NELIOTA project

The NELIOTA system is the first to use a 1.2 m-telescope for monitoring the Moon, and as such is able to detect flashes two magnitudes fainter than other lunar monitoring programs, which typically use 0.5 m-telescopes or smaller.


Another unique feature of the NELIOTA project is its ability to monitor the Moon in two ‘photometric bands’, which recently enabled the first-ever refereed publication to determine the temperature of lunar impact flashes – ranging from 1300 C to 2800 C.


A moderm approach to an ancient phenomenon


For at least a thousand years, people claim to have spotted flashes lighting up regions of the Moon, yet only recently have we had telescopes and cameras powerful enough to characterise the size, speed, and frequency of these events.


While our planet has lived with the risk, and reality, of bombardment from objects in space for as long as it has been in existence, we are now able to monitor our skies with more accuracy than ever before.



Near-Earth objects

The NELIOTA project relies on funding from ESA’s Science programme, and is one exciting part of ESA’s Space Situational Awareness programme, which is building infrastructure in space and on the ground to improve our monitoring and understanding of potential Earth hazards.


The programme is currently in the process of setting up a network of Flyeye telescopes across the globe, to scan the skies for risky asteroids, including those that could hit the Moon.


In the future, ESA will move towards mitigation and active planetary defence, and is currently planning the ambitious Hera mission to test asteroid deflection.


Related links:


SMART-1: https://www.esa.int/Our_Activities/Space_Science/SMART-1


Space Situational Awareness: http://www.esa.int/Our_Activities/Operations/Space_Situational_Awareness


Near-Earth Objects – NEO Segment: http://www.esa.int/Our_Activities/Operations/Space_Situational_Awareness/Near-Earth_Objects_-_NEO_Segment


Animation, Images, Text, Credits: ESA/P.Carril/NELIOTA project/Space-X (Space Exploration Institute), CC BY-SA 3.0 IGO/Theofanis Matsopoulos.


Greetings, Orbiter.chArchive link


Planetary Defense: The Bennu Experiment


NASA – OSIRIS-REx Mission logo.


December 7, 2018


On Dec. 3, after traveling billions of kilometers from Earth, NASA’s OSIRIS-REx spacecraft reached its target, Bennu, and kicked off a nearly two-year, up-close investigation of the asteroid. It will inspect nearly every square inch of this ancient clump of rubble left over from the formation of our solar system. Ultimately, the spacecraft will pick up a sample of pebbles and dust from Bennu’s surface and deliver it to Earth in 2023.


Generations of planetary scientists will get to study pieces of the primitive materials that formed our cosmic neighborhood and to better understand the role asteroids may have played in delivering life-forming compounds to planets and moons.



Image above: This artist’s concept shows the Origins Spectral Interpretation Resource Identification Security – Regolith Explorer (OSIRIS-REx) spacecraft contacting the asteroid Bennu with the Touch-And-Go Sample Arm Mechanism or TAGSAM. The mission aims to return a sample of Bennu’s surface coating to Earth for study as well as return detailed information about the asteroid and it’s trajectory. Image Credits: NASA’s Goddard Space Flight Center.


But it’s not just history that the mission to Bennu will help uncover. Scientists studying the rock through OSIRIS-REx’s instruments in space will also shape our future. As they collect the most detailed information yet about the forces that move asteroids, experts from NASA’s Planetary Defense Coordination Office, who are responsible for detecting potentially hazardous asteroids, will improve their predictions of which ones could be on a crash-course with our planet.


Here is how the OSIRIS-REx mission will support this work:


How scientists predict Bennu’s whereabouts


About a third of a mile, or half a kilometer, wide, Bennu is large enough to reach Earth’s surface; many smaller space objects, in contrast, burn up in our atmosphere. If it impacted Earth, Bennu would cause widespread damage. Asteroid experts at the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory in Pasadena, California, project that Bennu will come close enough to Earth over the next century to pose a 1 in 2,700 chance of impacting it between 2175 and 2196. Put another way, those odds mean there is a 99.963 percent chance the asteroid will miss the Earth. Even so, astronomers want to know exactly where Bennu is located at all times.


Astronomers have estimated Bennu’s future trajectory after observing it several times since it was discovered in 1999. They’ve turned their optical, infrared and radio telescopes toward the asteroid every time it came close enough to Earth, about every six years, to deduce features such as its shape, rotation rate and trajectory.


“We know within a few kilometers where Bennu is right now,” said Steven Chesley, senior research scientist at CNEOS and an OSIRIS-REx team member whose job it is to predict Bennu’s future trajectory.


Why Bennu’s future trajectory predictions get fuzzy


Scientists have estimated Bennu’s trajectory around the Sun far into the future. Their predictions are informed by ground observations and mathematical calculations that account for the gravitational nudging of Bennu by the Sun, the Moon, planets and other asteroids, plus non-gravitational factors.


Given these parameters, astronomers can predict the next four exact dates (in September of 2054, 2060, 2080 and 2135) that Bennu will come within 5 million miles (7.5 million kilometers or .05 astronomical units) of Earth. That’s close enough that Earth’s gravity will slightly bend Bennu’s orbital path as it passes by. As a result, the uncertainty about where the asteroid will be each time it loops back around the Sun will grow, causing predictions about Bennu’s future orbit to become increasingly hazy after 2060.



Image above: This image of Bennu was taken by the OSIRIS-REx spacecraft from a distance of around 50 miles (80 km). Image Credits: NASA/Goddard/University of Arizona.


In 2060, Bennu will pass Earth at about twice the distance from here to the Moon. But it could pass at any point in a 19-mile (30-kilometer) window of space. A very small difference in position within that window will get magnified enormously in future orbits and make it increasingly hard to predict Bennu’s trajectory.


As a result, when this asteroid comes back near Earth in 2080, according to Chesley’s calculations, the best window we can get on its whereabouts is nearly 9,000 miles (14,000 kilometers) wide. By 2135, when Bennu’s shifted orbit is expected to bring it closer than the Moon, its flyby window grows wider, to nearly 100,000 miles (160,000 kilometers). This will be Bennu’s closest approach to Earth over the five centuries for which we have reliable calculations.


“Right now, Bennu has the best orbit of any asteroid in our database,” Chesley said. “And yet, after that encounter in 2135, we really can’t say exactly where it is headed.”


There’s another phenomenon nudging Bennu’s orbit and muddying future impact projections. It’s called the Yarkovsky effect. Having nothing to do with gravity, the Yarkovsky effect sways Bennu’s orbit because of heat from the Sun.


“There are a lot of factors that might affect the predictability of Bennu’s trajectory in the future, but most of them are relatively small,” says William Bottke, an asteroid expert at the Southwest Research Institute in Boulder, Colorado, and a participating scientist on the OSIRIS-REx mission. “The one that’s most sizeable is Yarkvovsky.”


This heat nudge was named after the Polish civil engineer who first described it in 1901: Ivan Osipovich Yarkovsky. He suggested that sunlight warms one side of a small, dark asteroid and some hours later radiates that heat away as the asteroid rotates its hot side into cold darkness. This thrusts the rock pile a bit, either toward the Sun or away from it, depending on the direction of its rotation.


In Bennu’s case, astronomers have calculated that the Yarkovsky effect has shifted its orbit about 0.18 miles (284 meters) per year toward the Sunsince 1999. In fact, it helped deliver Bennu to our part of the solar system, in the first place, from the asteroid belt between Mars and Jupiter over billions of years. Now, Yarkovsky is complicating our efforts to make predictions about Bennu’s path relative to Earth.


Getting face-to-face with the asteroid will help


The OSIRIS-REx spacecraft will use its suite of instruments to transmit radio tracking signals and capture optical images of Bennu that will help NASA scientists determine its precise position in the solar system and its exact orbital path. Combined with existing, ground-based observations, the space measurements will help clarify how Bennu’s orbit is changing over time.


Additionally, astronomers will get to test their understanding of the Yarkovksy effect on a real-life asteroid for the first time. They will instruct the spacecraft to follow Bennu in its orbit about the Sun for about two years to see whether it’s moving along an expected path based on gravity and Yarkovsky theories. Any differences between the predictions and reality could be used to refine models of the Yarkovsky effect.


But even more significant to understanding Yarkovsky better will be the thermal measurements of Bennu. During its mission, OSIRIS-REx will track how much solar heat radiates off the asteroid, and where on the surface it’s coming from-data that will help confirm and refine calculations of the Yarkovsky effect on asteroids.


The spacecraft also will address some open questions about the Yarkovsky theory. One of them, said Chesley, is how do boulders and craters on the surface of an asteroid change the way photons scatter off of it as it cools, carrying away momentum from the hotter side and thereby nudging the asteroid in the opposite direction? OSIRIS-REx will help scientists understand by mapping the rockiness of Bennu’s surface.


“We know surface roughness is going to affect the Yarkovsky effect; we have models” said Chesley. “But the models are speculative. No one has been able to test them.”


After the OSIRIS-REx mission, Chesley said, NASA’s trajectory projections for Bennu will be about 60 times better than they are now.


Related article:


OSIRIS-REx Arrives at Bennu
https://orbiterchspacenews.blogspot.com/2018/12/osiris-rex-arrives-at-bennu.html


Related links:


Center for Near-Earth Object Studies (CNEOS): https://cneos.jpl.nasa.gov/


OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer): http://www.nasa.gov/mission_pages/osiris-rex/index.html


Images (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/JPL/DC Agle.


Best regards, Orbiter.chArchive link


2018 December 7 December’s Comet Wirtanen Image Credit…


2018 December 7


December’s Comet Wirtanen
Image Credit & Copyright: Juan Carlos Casado (TWAN, Earth and Stars)


Explanation: Coming close in mid-December, Comet 46P Wirtanen hangs in this starry sky over the bell tower of a Romanesque church. In the constructed vertical panorama, a series of digital exposures capture its greenish coma on December 3 from Sant Llorenc de la Muga, Girona, Catalonia, Spain, planet Earth. With an orbital period that is now about 5.4 years, the periodic comet’s perihelion, its closest approach, to the Sun will be on December 12. On December 16 it will be closest to Earth, passing at a distance of about 11.6 million kilometers or 39 light-seconds. That’s close for a comet, a mere 30 times the Earth-Moon distance. A good binocular target for comet watchers, Wirtanen could be visible to the unaided eye from a dark sky site. To spot it after dusk on December 16, look close on the sky to the Pleiades star cluster in Taurus.


∞ Source: apod.nasa.gov/apod/ap181207.html


Moeraki Boulders, New Zealand | #Geology #GeologyPage…


Moeraki Boulders, New Zealand | #Geology #GeologyPage #NewZealand


The Moeraki Boulders are unusually large and spherical boulders lying along a stretch of Koekohe Beach on the wave-cut Otago coast of New Zealand between Moeraki and Hampden. They occur scattered either as isolated or clusters of boulders within a stretch of beach where they have been protected in a scientific reserve.


The erosion by wave action of mudstone, comprising local bedrock and landslides, frequently exposes embedded isolated boulders. These boulders are grey-colored septarian concretions, which have been exhumed from the mudstone enclosing them and concentrated on the beach by coastal erosion.


Geology Page

www.geologypage.com

https://www.instagram.com/p/BrE7EeZlZnh/?utm_source=ig_tumblr_share&igshid=52cubg0d8vpb


Europe’s ancient proto-cities may have been ravaged by the plague

The Cucuteni-Trypillia culture of the Eneolithic Balkans and Eastern Europe is best know for its mega-settlements or proto-cities, each one featuring hundreds of homes, temples and other structures, and likely to have been inhabited by as many as 20,000 people. But from around 3,400 BC these mega-settlements were no longer being built, and a few hundred years later the Cucuteni-Trypillia culture vanished.
Two main explanations have been given for its rather swift demise: violent invasions by steppe pastoralists from the east and/or a massive out-migration by its people as a result of environmental impacts from rapid climate change (see here). However, these theories have failed to gain wide acceptance due to a lack of hard evidence in their support.
Now, another potential explanation is being offered, and it is supported by hard evidence. According to Rascovan et al., the plague may have been a key factor in the decline of not only the Cucuteni-Trypillia culture, but much of Neolithic Europe (see here). From the paper, emphasis is mine…



Between 5,000 and 6,000 years ago, many Neolithic societies declined throughout western Eurasia due to a combination of factors that are still largely debated. Here, we report the discovery and genome reconstruction of Yersinia pestis, the etiological agent of plague, in Neolithic farmers in Sweden, pre-dating and basal to all modern and ancient known strains of this pathogen. We investigated the history of this strain by combining phylogenetic and molecular clock analyses of the bacterial genome, detailed archaeological information, and genomic analyses from infected individuals and hundreds of ancient human samples across Eurasia. These analyses revealed that multiple and independent lineages of Y. pestis branched and expanded across Eurasia during the Neolithic decline, spreading most likely through early trade networks rather than massive human migrations. Our results are consistent with the existence of a prehistoric plague pandemic that likely contributed to the decay of Neolithic populations in Europe.

In this work, we report the discovery of plague infecting Neolithic farmers in Scandinavia, which not only pre-dates all known cases of plague, but is also basal to all known modern and ancient strains of Y. pestis. We identified a remarkable overlap between the estimated radiation times of early lineages of Y. pestis, toward Europe and the Eurasian Steppe, and the collapse of Trypillia mega-settlements in the Balkans/Eastern Europe.





Citation…
Rascovan et al., Emergence and Spread of Basal Lineages of Yersinia pestis during the Neolithic Decline, Cell (2019), https://doi.org/10.1016/j.cell.2018.11.005
See also…
Migration of the Bell Beakers—but not from Iberia (Olalde et al. 2018)
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…
“The Homeland: In the footprints of the early Indo-Europeans” time map

Source


Dark Matter 101: Looking for the missing mass

Here’s the deal — here at NASA we share all

kinds of amazing images of planets,

stars,

galaxies, astronauts,

other humans,

and such, but those photos can only capture part of what’s out there. Every

image only shows ordinary matter (scientists sometimes call it baryonic

matter), which is stuff made from protons, neutrons and electrons. The problem

astronomers have is that most of the

matter in the universe is not ordinary matter – it’s a mysterious substance called dark matter.  


image

What

is dark matter
? We don’t really know.

That’s not to say we don’t know anything about it – we can see its effects on

ordinary matter. We’ve been getting clues about what it is and what it is not

for decades. However, it’s hard to pinpoint its exact nature when it doesn’t

emit light our telescopes can see. 


Misbehaving

galaxies


The first hint that we might be missing

something came in the 1930s when astronomers noticed that the visible matter in

some clusters of galaxies wasn’t enough to hold the cluster together. The

galaxies were moving so fast that they should have gone zinging out of the

cluster before too long (astronomically speaking), leaving no cluster behind.


image


Simulation credit: ESO/L. Calçada



It turns out, there’s a similar problem with individual galaxies.

In the 1960s and 70s, astronomers mapped out how fast the stars in a galaxy

were moving relative to its center. The outer parts of every single spiral

galaxy the scientists looked at were traveling so fast that they should have

been flying apart.


image

Something was missing – a lot of it! In

order to explain how galaxies moved in clusters and stars moved in individual

galaxies, they needed more matter than scientists could see. And not just a little more matter. A lot … a lot, a lot. Astronomers

call this missing mass “dark matter”
— “dark” because we don’t know

what it is. There would need to be five times as much dark matter as ordinary

matter to solve the problem.  


Holding

things together


Dark matter keeps galaxies and galaxy clusters

from coming apart at the seams, which means dark matter experiences gravity

the same way we do
.


image

In addition to holding things together, it

distorts space like any other mass. Sometimes we see distant

galaxies whose light has been bent around massive objects
on its way

to us. This makes the galaxies appear stretched out or contorted. These distortions provide another measurement of dark

matter
.


Undiscovered

particles?


There have been a number of theories over the

past several decades about what dark matter could be; for example, could dark

matter be black holes and neutron stars – dead stars that aren’t shining anymore?

However, most of the theories have been disproven. Currently, a leading class

of candidates involves an as-yet-undiscovered type of elementary particle

called WIMPs, or Weakly Interacting Massive Particles.


image

Theorists have envisioned a range of WIMP

types and what happens when they collide with each other. Two possibilities are

that the WIMPS could mutually annihilate, or they could produce an

intermediate, quickly decaying particle. In both cases, the collision would end

with the production of gamma rays — the most energetic form of light — within the detection range of our Fermi Gamma-ray Space Telescope.


Tantalizing

evidence close to home


A few years ago, researchers took a look at

Fermi data from near the center of our galaxy and subtracted out the gamma rays

produced by known sources. There was a left-over gamma-ray signal, which could be consistent with some forms of dark matter.


image

While it was an exciting finding, the case is

not yet closed because lots of things at the center of the galaxy make gamma

rays. It’s going to take multiple sightings using other experiments and looking

at other astronomical objects to know

for sure if this excess is from dark matter.


image

In the meantime, Fermi will continue the search, as it has over its 10 years

in space. Learn

more about Fermi and how we’ve been celebrating its first decade in space.


Make

sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.  


HiPOD (6 December 2018): Eastern Rim of a Crater in Terra…



HiPOD (6 December 2018): Eastern Rim of a Crater in Terra Cimmeria


   – Alt: 258 km. Black and white is less than 5 km across; enhanced color is less than 1 km.


NASA/JPL/University of Arizona


NASA’s Mars InSight Flexes Its Arm


NASA – InSight Mission patch.


Dec. 6, 2018


New images from NASA’s Mars InSight lander show its robotic arm is ready to do some lifting.



Image above: This image from InSight’s robotic-arm mounted Instrument Deployment Camera shows the instruments on the spacecraft’s deck, with the Martian surface of Elysium Planitia in the background. The image was received on Dec. 4, 2018 (Sol8). Image Credits: NASA/JPL-Caltech.


With a reach of nearly 6 feet (2 meters), the arm will be used to pick up science instruments from the lander’s deck, gently setting them on the Martian surface at Elysium Planitia, the lava plain where InSight touched down on Nov. 26.



Image above: An image of InSight’s robotic arm, with its scoop and stowed grapple, poised above the Martian soil. The image was received on Dec. 4, 2018 (Sol 8). Image Credits: NASA/JPL-Caltech.


But first, the arm will use its Instrument Deployment Camera, located on its elbow, to take photos of the terrain in front of the lander. These images will help mission team members determine where to set InSight’s seismometer and heat flow probe — the only instruments ever to be robotically placed on the surface of another planet.


“Today we can see the first glimpses of our workspace,” said Bruce Banerdt, the mission’s principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By early next week, we’ll be imaging it in finer detail and creating a full mosaic.”


Another camera, called the Instrument Context Camera, is located under the lander’s deck. It will also offer views of the workspace, though the view won’t be as pretty.



Image above: A partial view of the deck of NASA’s InSight lander, where it stands on the Martian plains Elysium Planitia. The image was received on Dec. 4, 2018 (Sol 8). Image Credits: NASA/JPL-Caltech.


“We had a protective cover on the Instrument Context Camera, but somehow dust still managed to get onto the lens,” said Tom Hoffman of JPL, InSight’s project manager. “While this is unfortunate, it will not affect the role of the camera, which is to take images of the area in front of the lander where our instruments will eventually be placed.”


Placement is critical, and the team is proceeding with caution. Two to three months could go by before the instruments have been situated and calibrated.


Over the past week and a half, mission engineers have been testing those instruments and spacecraft systems, ensuring they’re in working order. A couple instruments are even recording data: a drop in air pressure, possibly caused by a passing dust devil, was detected by the pressure sensor. This, along with a magnetometer and a set of wind and temperature sensors, are part of a package called the Auxiliary Payload Sensor Subsystem, which will collect meteorological data.



Animation above: Latest InSight Raw Images Animated. Cameras: Instrument Context Camera (ICC)/Instrument Deployment Camera (IDC)/Animation: Images Credits: NASA/JPL-Caltech/InSight/Animation Credits: Orbiter.ch Aerospace Studio 2018/Roland Berga.


More images from InSight’s arm were scheduled to come down this past weekend. However, imaging was momentarily interrupted, resuming the following day. During the first few weeks in its new home, InSight has been instructed to be extra careful, so anything unexpected will trigger what’s called a fault. Considered routine, it causes the spacecraft to stop what it is doing and ask for help from operators on the ground.


“We did extensive testing on Earth. But we know that everything is a little different for the lander on Mars, so faults are not unusual,” Hoffman said. “They can delay operations, but we’re not in a rush. We want to be sure that each operation that we perform on Mars is safe, so we set our safety monitors to be fairly sensitive initially.”


Spacecraft engineers had already factored extra time into their estimates for instrument deployment to account for likely delays caused by faults. The mission’s primary mission is scheduled for two Earth years, or one Mars year — plenty of time to gather data from the Red Planet’s surface.


About InSight:


JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.


A number of European partners, including France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and the Institut de Physique du Globe de Paris (IPGP) provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.


For more information about InSight, visit: https://mars.nasa.gov/insight/


Images (mentioned), Animation (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.


Best regards, Orbiter.chArchive link


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