среда, 24 апреля 2019 г.

Halite | #Geology #GeologyPage #Mineral Locality: Wieliczka…


Halite | #Geology #GeologyPage #Mineral


Locality: Wieliczka Mine, Wieliczka, Małopolskie, Poland


Size: 13 x 10 x 9 cm


Photo Copyright © Anton Watzl Minerals


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Fluorite | #Geology #GeologyPage #Mineral Locality: Boltsburn…


Fluorite | #Geology #GeologyPage #Mineral


Locality: Boltsburn Mine, Weardale, Co Durham, England, Europe


Dimensions: 11.0 × 7.0 × 5.0 cm


Photo Copyright © Crystal Classics


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Baryte (stalactite section) | #Geology #GeologyPage…


Baryte (stalactite section) | #Geology #GeologyPage #Mineral


Locality: Portaway Mine, Dirtlow Rake, Peak Forest, Derbyshire, England, Europe


Dimensions: 14.6 × 10.8 × 0.8 cm


Photo Copyright © Crystal Classics


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Quartz With Schorl & Hyalite | #Geology #GeologyPage…


Quartz With Schorl & Hyalite | #Geology #GeologyPage #Mineral


Locality: Davib East Farm, Karibib District, Erongo Region, Namibia


Size: 16.5 × 10.2 × 8 cm


Largest Crystal: 16.50cm


Photo Copyright © Wittig-Minerals /e-rocks. com


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2019 April 24 The Shape of the Southern Crab Image Credit:…


2019 April 24


The Shape of the Southern Crab
Image Credit: NASA, ESA, STScI


Explanation: The symmetric, multi-legged appearance of the Southern Crab Nebula is certainly distinctive. About 7,000 light-years distant toward the southern sky constellation Centaurus, its glowing nested hourglass shapes are produced by the remarkable symbiotic binary star system at its center. The nebula’s dramatic stellar duo consists of a hot white dwarf star and cool, pulsating red giant star shedding outer layers that fall onto the smaller, much hotter companion. Embedded in a disk of material, outbursts from the white dwarf cause an outflow of gas driven away both above and below the disk resulting in the bipolar hourglass shapes. The bright central shape is about half a light-year across. This new Hubble Space Telescope image celebrates the 29th anniversary of Hubble’s launch on April 24, 1990 on board the Space Shuttle Discovery.


∞ Source: apod.nasa.gov/apod/ap190424.html


HiRISE Update: Message from the Principal Investigator Blurred…


HiRISE Update: Message from the Principal Investigator 


Blurred images and the health of MRO’s battery were worrisome issues, but we now have good news about them both.


Read more: https://www.uahirise.org/epo/2019-apr-23


One Year of Leadership

image

It’s been one year since Jim Bridenstine was sworn in as our 13th administrator, starting the job on April 23, 2018. Since then, he has led the agency towards taking our nation farther than ever before — from assigning the first astronauts to fly on commercial vehicles to the International Space Station, to witnessing New Horizon’s arrival at the farthest object ever explored, to working to meet the challenge of landing humans on the lunar surface by 2024.


Here is a look at what happened in the last year under the Administrator’s leadership:


1. Assigned the first astronauts to fly on commercial spacecraft to the International Space Station.


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Administrator Bridenstine introduced to the world on Aug. 3, 2018 the first U.S. astronauts who will fly on American-made, commercial spacecraft to and from the International Space Station — an endeavor that will return astronaut launches to U.S. soil for the first time since the space shuttle’s retirement in 2011.


“Today, our country’s dreams of greater achievements in space are within our grasp,” said Administrator Bridenstine. “This accomplished group of American astronauts, flying on new spacecraft developed by our commercial partners Boeing and SpaceX, will launch a new era of human spaceflight.”


2. Announced the first commercial effort to regularly send science payloads to the Moon.


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Administrator Bridenstine announced new Moon partnerships with American companies — an important step to achieving long-term scientific study and human exploration of the Moon and Mars. Nine U.S. companies were named as eligible to bid on NASA delivery services to the Moon through Commercial Lunar Payload Services (CLPS) contracts on Nov. 29, 2018.  


3. Witnessed the teamwork that led to the latest mission to the Red Planet with Mars InSight’s landing.


image

On Nov. 26, 2018, the InSight lander successfully touched down on Mars after an almost seven-month, 300-million-mile (485-million-kilometer) journey from Earth. Administrator Bridenstine celebrated with the members of Mars Cube One and Mars InSight team members after the Mars lander successfully landed and began its mission to study the “inner space” of Mars: its crust, mantle and core.


“Today, we successfully landed on Mars for the eighth time in human history,” said NASA Administrator Jim Bridenstine. “InSight will study the interior of Mars, and will teach us valuable science as we prepare to send astronauts to the Moon and later to Mars…The best of NASA is yet to come, and it is coming soon.”


4. Oversaw the arrival of the first American mission to an asteroid designed to return samples and New Horizon’s arrival at Ultima Thule, the farthest object ever explored.


image

The spacecraft OSIRIS-REx traveled 1.4 million miles (2.2 million kilometers) to arrive at the asteroid Bennu on Dec. 3. The first asteroid sample mission is helping scientists investigate how planets formed and how life began, as well as improve our understanding of asteroids that could impact Earth. OSIRIS-Rex has already revealed water locked inside the clays that make up the asteroid.


And on the early hours of New Year’s Day, 2019, our New Horizons spacecraft flew past Ultima Thule in Kuiper belt, a region of primordial objects that hold keys to understanding the origins of the solar system.


“In addition to being the first to explore Pluto, today New Horizons flew by the most distant object ever visited by a spacecraft and became the first to directly explore an object that holds remnants from the birth of our solar system,” said Administrator Bridenstine. “This is what leadership in space is all about.”


5. Directed the first major milestone in commercial crew flights with the successful Space X Demo-1 mission.


image

Demonstration Mission-1 (Demo-1) was an uncrewed flight test designed to demonstrate a new commercial capability developed under NASA’s Commercial Crew Program. The mission began March 2, when the Crew Dragon launched from NASA’s Kennedy Space Center in Florida and docked to the International Space Station for five days.


“Today’s successful re-entry and recovery of the Crew Dragon capsule after its first mission to the International Space Station marked another important milestone in the future of human spaceflight,” said Administrator Bridenstine. “I want to once again congratulate the NASA and SpaceX teams on an incredible week. Our Commercial Crew Program is one step closer to launching American astronauts on American rockets from American soil.”


6. Is currently working to meet the challenge of advancing human exploration of the lunar surface to 2024.


image

Administrator Bridenstine has accomplished a lot since he swore in one year ago — but the best is yet to come. On March 26, Vice President Mike Pence tasked our agency with returning American astronauts to the Moon by 2024 at the fifth meeting of the National Space Council. 


“It is the right time for this challenge, and I assured the Vice President that we, the people of NASA, are up to the challenge,” said Administrator Bridenstine. “There’s a lot of excitement about our plans and also a lot of hard work and challenges ahead, but I know the NASA workforce and our partners are up to it.”


Learn more about what’s still to come this year at NASA:



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


Precious Metal : The 15 Most Precious Metal in the World…


Precious Metal : The 15 Most Precious Metal in the World http://www.geologypage.com/2019/04/precious-metal-the-15-most-precious-metal-in-the-world.html


Human influence on climate change is traced back to the 19th century

Climate change poses a serious challenge to the human society and it is generally believed that humans are themselves to blame. The Intergovernmental Panel on Climate Change has concluded that, with high confidence, human activities are responsible for the continuing rise of global mean surface air temperature since the 1950s.











Human influence on climate change is traced back to the 19th century
A graphic illustration for the anthropogenic-induced decrease in the difference of summer and winter temperatures.
The thermometers represent the difference between summer and winter temperatures
[Credit: Jianping Duan]

A recent article published in the journal Nature Sustainability by Duan et al. has shown that human influence on climate change can be traced back to the late 19th century based on summer-winter temperature difference. This research has been carried out by scientists from the Institute of Atmospheric Physics, Chinese Academy of Sciences in collaboration with leading experts on climate research from the UK and Germany.


«It is well known that humans are driving global warming, but when did this begin?» said the lead author, Dr Jianping Duan, «Our study has shown that anthropogenic influence on climate change started much earlier than we previously believe.»


Anthropogenic climate change is usually focused on the rise of surface air temperature, namely global warming, and the increase of climate extremes. Duan et al. (2019) have found that the amplitude of seasonal temperature fluctuations has been decreasing widely, and this trend can be traced back to the late 19th century.


They find that temperature seasonality had been stable until 1860s, from which there have been continuous downward trends across northern hemisphere mid-high latitudes. A formal detection and attribution analysis using the latest climate model simulations has shown that increased greenhouse gas concentrations and anthropogenic aerosols are the main contributors to the observed downward trends.


Source: Chinese Academy of Sciences [April 22, 2019]



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Archive


Researchers calculate decades of ‘scary’ Greenland ice melting

Measuring melting ice is a fairly precise business in 2019—thanks to satellites, weather stations and sophisticated climate models.











Researchers calculate decades of 'scary' Greenland ice melting
Satellites are used to measure ice loss in Greenland
[Credit: Jeff Schmaltz/AFP]

By the 1990s and 2000s, scientists were able to make pretty good estimates, although work from previous decades was unreliable due to less advanced technology.


Now, researchers have recalculated the amount of ice lost in Greenland since 1972, the year the first Landsat satellites entered orbit to regularly photograph the Danish territory.


«When you look at several decades, it is best to sit back in your chair before looking at the results, because it is a bit scary to see how fast it is changing,» said French glaciologist Eric Rignot, of the University of California at Irvine.


Rignot co-authored the study, published in the Proceedings of the National Academy of Sciences,with colleagues in California, Grenoble, Utrecht and Copenhagen.


«It’s also something that affects the four corners of Greenland, not just the warmer parts in the south,» he said.


Ice melting six times faster


Glaciologists use three methods to measure ice melting.


Firstly, satellites measure altitude with a laser: if a glacier melts, the satellite picks up its reduced height.


A second technique involves measuring variations in gravity, as ice loss can be detected through a decrease in gravitational pull. This method has been available since 2002 using NASA satellites.


Thirdly, scientists have developed so-called mass balance models, which compare mass accumulated (rain and snow) with mass lost (ice river discharges) to calculate what is left.











Researchers calculate decades of 'scary' Greenland ice melting
The Zachariae Glacier on Greenland’s east coast is seen in a photograph
taken by a NASA satellite [Credit: AFP] 

These models, confirmed with field measurements, have become very reliable since the 2000s, according to Rignot—boasting a five to seven percent margin of error, compared to 100 percent a few decades ago.


The research team used these models to «go back in time» and reconstruct Greenland’s ice levels in the 1970s and 1980s.


The limited data available for this period—medium-quality satellite photos, aerial photos, ice cores and other observations—helped refine them.


«We added a little bit of history that did not exist,» said Rignot.


The results: during the 1970s, Greenland accumulated 47 gigatonnes of ice per year, on average. Then, it lost an equivalent volume in the 1980s.


The melting continued at that rate in the 1990s, before a sharp acceleration in the 2000s (187 Gt/year) and even more since 2010 (286 Gt/year).


Ice is melting six times faster than in the 1980s, researchers estimate—and Greenland’s glaciers alone have contributed to a 13.7 millimeter rise in sea levels since 1972, they believe.


«This is an excellent piece of work by a well-established research group using novel methods to extract more information from the available data», said Colin Summerhayes, of the Scott Polar Research Institute in Cambridge.


As with a similar study carried out by the same team on Antarctica, the new study affords a longer term view of the rapid ice melt being observed in Greenland in recent years.


«This new data better enables us to put recent, dramatic, changes to Greenland’s contribution to global sea level rise into a longer-term context—the ice loss we’ve seen in the last eight years is as much as was lost in the preceding four decades,» said Amber Leeson, a lecturer in Environmental Data Science at Lancaster University.


Author: Ivan Couronne | Source: AFP [April 22, 2019]



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Archive


First Seisms Detected on Mars


NASA — InSight Mission patch.


April 23, 2019


A Martian tremor has been recorded on the red planet. This should allow, in the long run, to learn more about its history.



 First Likely Marsquake Heard by NASA’s InSight

Video above: This video and audio illustrates a seismic event detected by NASA’s Mars InSight rover on April 6, 2019, the 128th Martian day, or sol, of the mission. Three distinct kinds of sounds can be heard, all of them detected as ground vibrations by the spacecraft’s seismometer, called the Seismic Experiment for Interior Structure (SEIS): noise from Martian wind, the seismic event itself, and the spacecraft’s robotic arm as it moves to take pictures. Video Credits: NASA/JPL-Caltech/CNES/IPGP/Imperial College London.


«A weak but distinct seismic signal»: the French seismometer SEIS deployed on Mars as part of the US mission InSight captured, April 6, its first Martian earthquake, said Tuesday the French space agency CNES.


«It’s great to finally have the sign that there is still seismic activity on Mars,» enthuses in a statement Philippe Lognonné, researcher of the Institute of Physics of the Globe of Paris. «We waited for our first Martian earthquake for months,» adds the father of the precious instrument.



Image above: NASA’s InSight Lander and its Wind and Thermal Shield of SEIS (Seismic Experiment for Interior Structure) on April 18 (Sol 135). Image Credits: NASA / JPL.


Seismic Experiment for Interior Structure (SEIS) seismometer, whose technical and scientific responsibility is French, was deposited on 19 December 2018 on Martian soil thanks to an automatic arm of the InSight lander arrived on the red planet on 26 November.


His goal ? Listen to beat the heart of Mars and, earthquake after earthquake, learn more about the history of its formation that occurred billions of years ago.


Three other signals


If, according to Bruce Banerdt, scientific leader of the mission within NASA, the tremor, which occurred on the 128th Martian day of the mission, «marks the official birth of a new discipline: Martian seismology», it turns out to be too weak to provide useful data on the inside of Mars.


And, according to scientists, it also remains to be confirmed that the recorded tremor has its origin in the interior of the planet and is not due to the effect of wind or other sources of parasitic noise.



Mars InSight Mission logo. Animation Credits: NASA / JPL

Three other signals, but much weaker than that of April 6, have been detected in the last two months.


Related article:


InSight’s Seismometer Now Has a Cozy Shelter on Mars
https://orbiterchspacenews.blogspot.com/2019/02/insights-seismometer-now-has-cozy.html


Related links:


CNES Press Release (In French): https://insight.cnes.fr/fr/insight-de-battre-le-coeur-de-mars-commence


Seismic Experiment for Interior Structure (SEIS): https://mars.nasa.gov/insight/mission/instruments/seis/


InSight Mars Lander: https://www.nasa.gov/mission_pages/insight/main/index.html


Image (mentioned), Animation (mentioned), Text, Credits: AFP / CNES / NASA / JPL / Orbiter.ch Aerospace / Roland Berga.


Greetings, Orbiter.chArchive link


Major Incident for SpaceX: Crew Dragon Capsule Exploded in Ground Test


SpaceX  — Crew Dragon / NASA Demo-1 patch.


April 23, 2019


On April 20, 2019, during a static test, the Crew Dragon capsule that had flown to the ISS was likely completely destroyed. It was to be reused for an emergency ejection test in mid-June. The next flight of a Dragon ship, which was to be flown by two astronauts, will be delayed.



Image above: Explosion of the Dragon capsule during a ground test on April 20, 2019. Image Credit: Florida Today.


SpaceX and NASA probably suffered another major setback on April 20, 2019. Indeed, the Crew Dragon capsule that returned to Earth on March 8 after a successful mission to the International Space Station (ISS) was destroyed in an explosion. In any case, this is what a video broadcast on social networks suggests (anonymously, perhaps by an employee of SpaceX) and photos taken miles away from the Kennedy Space Center showing a large cloud of orange smoke rise from the test area.


As pressure-fed rocket engines specifically designed to be the basis of a launch escape system, Crew Dragon and its SuperDraco thrusters are meant to be ready to ignite at a millisecond’s notice once they are armed in a flight-ready configuration. It’s safe to say that ten seconds away from a specifically planned ignition is one of those moments, although there is a limited chance that SpaceX’s static fire procedures intentionally diverge from an abort-triggered ignition. Regardless, the fact that Crew Dragon was destroyed before the ignition of its SuperDracos is not an encouraging sign.



Artist’s view of SpaceX Crew Dragon docking at ISS. Image Credit: NASA

Instead of a problem with its high-performance abort thrusters, it can be tentatively concluded that Crew Dragon’s explosion originated in its fuel tanks or propellant plumbing. Such an immediate and energetic explosion points more towards a total failure of propellant lines or valves (or their avionics), while another – and potentially far more concerning – cause could be one of Crew Dragon’s pressure vessels. In a space as enclosed as a Dragon capsule, the rupture of a pressure vessel could trigger a chain reaction of pressure vessel failures, freeing both oxidizer (NTO) and fuel (MMH). Known as hypergolic propellant, NTO and MMH ignite immediately (and violently so) when mixed.


It’s quite possible that the accident investigation to follow will be SpaceX’s most difficult and trying yet. Regardless of the specific cause, the footage of Crew Dragon C201’s demise does not support any positive conclusions about the fate of astronauts or passengers, had they been aboard during the violent explosion. Seemingly triggered in some way by the very system meant to safely extricate Crew Dragon and its astronauts from a failing Falcon 9 rocket, major work will need to be done to prove to NASA that the spacecraft is safe. Sadly, Boeing’s Starliner spacecraft – funded in parallel with Crew Dragon under NASA’s Commercial Crew Program – suffered a far less severe but no less significant failure during a static fire test of its own abort thrusters. Boeing was forced to remove the impacted hardware from its flight plans to extensively clean, repair, and rework the service module.



SuperDraco — Test Fire. Video Credit: SpaceX

NASA is now faced with the fact that both of the spacecraft it supported with CCP have exhibited major failures related to their launch escape systems. Crew Dragon’s catastrophic explosion comes as a particularly extreme surprise given how extensively SpaceX has already tested the SuperDraco engines and plumbing, as well as the successful completion of the spacecraft’s launch debut. In the process of DM-1 launch preparations, Crew Dragon likely spent a minimum of 80 minutes with its SuperDraco thrusters and propellant systems primed and ready to abort at any second, apparently without a single mildly-concerning issue.


Godspeed to SpaceX and NASA as they enter into this challenging and unplanned failure investigation.


Related articles:


NASA, SpaceX Launch First Flight Test of Space System Designed for Crew
https://orbiterchspacenews.blogspot.com/2019/03/nasa-spacex-launch-first-flight-test-of.html


SpaceX Crew Dragon Undock from ISS and Splashes Down in Atlantic Ocean
https://orbiterchspacenews.blogspot.com/2019/03/spacex-crew-dragon-undock-from-iss-and.html


Related links:


SpaceX Crew Dragon: https://blogs.nasa.gov/commercialcrew


Commercial Crew Program: https://www.nasa.gov/exploration/commercial/crew/index.html


SpaceX: https://www.spacex.com/


Images (mentioned), Video (mentioned), Text, Credits: Florida Today/Orbiter.ch Aerospace/Roland Berga.


Greetings, Orbiter.chArchive link


How does wildlife fare after fires?

Fire ecologists and wildlife specialists at La Trobe University have made key discoveries in how wildlife restores itself after bushfires, and what Australian conservationists can do to assist the process.











How does wildlife fare after fires?
Credit: La Trobe University

The study, published this week in Wildlife Research journal, looks at various reserves in the Australian state of Victoria after bushfires had taken place. It finds that the surrounding area of any fire dictates what species survived and went onto thrive.


Key findings of the study included:


— Invasive species such as Australian ravens, magpies and house mice were commonly found recolonising burnt areas surrounded by agriculture;


— Native species such as crested bellbirds, hopping mice and white-eared honeyeater were commonly found recolonising burnt areas surrounded by mallee vegetation; and


— Other native species such as Major Mitchell’s cockatoos, mallee ringnecks and white-winged choughs were commonly found recolonising burnt areas surrounded by a mix of mallee vegetation and sparse grassy woodland.


To minimise damage of large bushfires and to protect important species and vegetation, strategic burns create firebreaks — vital in slowing the spread of fire.


La Trobe honours student Angela Simms, author of the study, said the study opens up an important discussion on how conservationists can make informed decisions on planned and strategic burning.


«With our dry climate, Australia has seen more than its fair share of destructive bushfires. This, in conjunction with increasing habitat loss more generally, means that it’s not uncommon to see localized extinctions of species after a fire.


«We can conclude that the surrounding habitat and vegetation to a fire directly determines the species that will recolonize that area.


«From this, we know the wider landscape context — particularly surrounding species and vegetation — should be a key consideration for conservation programs when planning locations for strategic burns.


«But it also tells us a lot about what to expect when a bushfire does take place, and what preparations they can undertake to restore native wildlife that could be vulnerable when needed.


«There is still much to learn about post-fire fauna communities but this study marks the start of a journey to better understand how we can protect important wildlife before, during and after fires.»


Source: La Trobe University [April 22, 2019]



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Geomagnetic jerks finally reproduced and explained

Initially described in 1978, geomagnetic jerks are unpredictable events that abruptly accelerate the evolution of the Earth’s magnetic field, and skew predictions of its behaviour on a multi-year scale. Our magnetic field affects numerous human activities, ranging from establishing the direction in smartphones to the flight of low-altitude satellites. It is therefore essential to accurately predict its evolution. Still, geomagnetic jerks have presented a problem for geophysicists for over forty years.











Geomagnetic jerks finally reproduced and explained
Visualization of the interior of the Earth’s core, as represented by a computer simulation model (view of the equatorial
 plane and a spherical surface near the inner core, seen from the North Pole). Magnetic field lines (in orange) are
 stretched by turbulent convection (in blue and red). Hydromagnetic waves are emitted from the inner core,
and spread along the magnetic field lines up to the core’s boundary, where they are focused and give rise
to geomagnetic jerks [Credit: Aubert et al./IPGP/CNRS Photo library]

The Earth’s magnetic field is produced by the circulation of matter within its metallic core, via the energy released when this core cools. Researchers know of two types of movements that cause two types of variations in the magnetic field: those resulting from slow convection movement, which can be measured on the scale of a century, and those resulting from «rapid» hydromagnetic waves, which can be detected on the scale of a few years. They suspected that the latter played a role in the jerks, but the interaction of these waves with slow convection, along with their mechanism of propagation and amplification, had yet to be revealed.
To solve this mystery, Julien Aubert from l’Institut de physique du globe de Paris (CNRS/IPGP/IGN/Université de Paris) developed, with a colleague from the Technical University of Denmark (DTU), a computer simulation very close to the physical conditions of our core. The simulation required the equivalent of 4 million hours of calculation, and was carried out thanks to the supercomputers of GENCI.


Researchers were subsequently able to reproduce the succession of events leading to geomagnetic jerks, which arise in the simulation from hydromagnetic waves emitted in the inner core. These waves are focused and amplified as they approach the core’s surface, causing magnetic disturbances comparable in all ways to the jerks observed.


The digital reproduction and comprehension of these jerks paves the way for better predictions of the Earth’s magnetic field. Identifying the cause of magnetic field variations could also help geophysicists study the physical properties of the Earth’s core and inner mantle.


The research was published in Nature Geoscience.


Source: CNRS [April 22, 2019]



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Better labour practices could improve archaeological output

Archaeological excavation has, historically, operated in a very hierarchical structure, according to archaeologist Allison Mickel. The history of the enterprise is deeply entangled with Western colonial and imperial pursuits, she says. Excavations have been, and often still are, according to Mickel, led by foreigners from the West, while dependent on the labour of scores of people from the local community to perform the manual labour of the dig.











Better labour practices could improve archaeological output
An excavation site in Petra, Jordan [Credit: Allison Mickel]

In a recently published paper examining some of this history specifically in the context archaeological excavations undertaken in the Middle East, Mickel writes: «Even well into the 20th century, locally hired excavation workers continued to benefit little from working on archaeological projects, still predominantly directed by European and American researchers who paid extremely low wages and did not share their purpose, progress, hypotheses, or conclusions with local community members.»


Over time, the teams have gotten smaller in size, but hiring and labour practices remain the same, explains Mickel, an assistant professor of anthropology at Lehigh University, who specializes in the Middle East.


«We haven’t really changed the hierarchy of how we hire or the fact that workers are paid minimum wage—sometimes as little as a few dollars a day, which is not very much to spend even in their own context, for work that is dangerous and has a lot of risk to it,» she says.


In a new paper published in Archaeologies: Journal of the World Archaeological Congress, Mickel illuminates the ways that nineteenth century archaeologists working in the Middle East managed local labour in ways that reflected capitalist labour management models. She focuses on two case studies from early Middle Eastern archaeology by examining the memoirs of two 19th century archaeologists: Italian archaeologist Giovanni Battista Belzoni, known for his work in Egypt, and British archaeologist Sir Austen Henry Layard, best known for his work in Nimrud, an ancient Assyrian city about 20 miles south of Mosul, Iraq.


Mickel’s analysis reveals the different ways local labourers responded to similar conditions. Her examination ultimately reveals how much archaeological knowledge has fundamentally relied upon the active choices made by the local labourers who do the digging.


Divergent responses to exploitative labour practices


Mickel argues that the framework established by the German philosopher and economist Karl Marx of the capitalist mode of production can be seen in 19th century archaeological work in the Middle East?and, in many ways, in archaeological projects today. This includes Marx’s assertion that, she writes, «…the capitalist mode of production leads to workers experiencing a sense of powerlessness and an inability to fulfill the potential of their own skills, expertise, and abilities.»


In Mickel’s analysis, Belzoni’s approach to securing and retaining local labourers for his work in Egypt, which began in 1816, exemplified the conditions of modes of production that lead to his workers’ «…alienation in the Marxist sense,» beginning with how little he paid them.


She writes: «Monetarily devaluing the archaeological work of native Egyptians in this way engenders an understanding that archaeological labour is quite literally of little worth—one that in Marx’s view deeply impacts the self-image of the workers in a production process. Not only were the workers paid next to nothing for performing the manual labour of Belzoni’s endeavors, they were also not involved in the conceptualization of the project. In the end, the antiquities were subsequently shipped thousands of miles away, challenging both ideologically and spatially any relationship between the workers and the archaeological objects being unearthed through excavation, as well as the knowledge gleaned from them.»


Mickel also writes about Belzoni’s use of strongarm tactics to maintain the workforce he employed. These include resorting to physical violence and bribery?strategies Belzoni used, in one example, on a foreman to force labourers to return to work during a strike.


During his famed excavation of the Memnon Head in 1816, Belzoni had to leave the site for an extended period of time in order to raise funds. He believed, writes Mickel, «…that the workers and their families were too lazy to dig on their own…»


«Indeed,» she continues, «no substantial digging proceeded in Belzoni’s absence by the time he returned. The reasons for this surely have nothing to with any indolence on the part of the native Egyptian workforce, but rather can be explained in terms of alienation.»


In examining Layard’s memoir, Mickel finds that although Layard worked in the same region and during the same time period as Belzoni, his workers’ responded to similar working conditions very differently.


«Operating under extremely similar circumstances,» writes Mickel, «the groups of workers examined here made very divergent decisions about how best to respond to an exploitative labour system, whether to rise up demonstratively against it or to resist the devaluation of their work by establishing themselves as essential to the production of artifacts and historical knowledge.»


Layard’s strategies for hiring and managing a local labour force had much in common with Belzoni’s, including elements of capitalist labour relations modes such as low wages. Additionally, Layard’s memoirs suggest «…that he viewed the total excavation endeavor as metaphorically signifying the superiority of Western civilization over Oriental peoples and cultures.»


And yet Layard’s workmen, explains Mickel, often appear in his writing as trusted experts in the excavation process: «These men developed impressive excavation abilities that Layard himself recognized, repeatedly hiring the same groups of people for season after season and site after site. One native Assyrian man whom he hired again and again, Hormuzd Rassam, ultimately went on to lead his own excavations on behalf of the British Museum at places like Nimrud and Nineveh; Rassam even published his own archaeological memoirs for popular distribution like Layard and other archaeologists of the time»


Mickel compares these two contexts and concludes: «Operating under extremely similar circumstances, the groups of workers examined here made very divergent decisions about how best to respond to an exploitative labour system, whether to rise up demonstratively against it or to resist the devaluation of their work by establishing themselves as essential to the production of artifacts and historical knowledge.»


Focusing attention on the divergent decision these two groups of labourers made reveals how much is owed to archaeological workers’ localized responses to a structure designed to maximize benefit to the archaeologists and minimize workers’ control within the project, asserts Mickel.


She writes: «What would the archaeological record look like if this was not the case? How would archaeological knowledge be transformed if the means of its production were not controlled by archaeologists alone but shared with local stakeholders?»


Digging and questioning


As part of her work, Mickel supervises and participates in excavations in regions such as Petra, Jordan and Catalhoyuk, Turkey, while researching the history of archaeology and its contemporary practice.


Mickel has spent two to three months each summer in Turkey and Jordan, and between 2011 and 2015 spent a year at both sites, conducting dissertation fieldwork on a Fulbright grant.


«What I find in [Petra and Catalhoyuk] is relevant to a lot of other contexts because archaeology is fairly regional in its practice,» she says.


Beyond digging, Mickel examines records of archaeological excavations for the individuals listed as site workers. She visits their homes and asks questions about the site workers’ experiences on the excavations.


«I found that this system has led to one in which workers are doing this dance all the time in archaeology where they are integral to carrying out an excavation, they work for almost nothing, they are good at what they do, they have decades of experience in addition to generational knowledge that’s been handed down. … Most of these people, for context, their fathers worked in archaeology, their grandfathers worked in archaeology—it’s almost like a family business for them to be there. So they have a ton of knowledge, but if I tell them how much I admire their expertise, they react really negatively to that label of expertise.»


Mickel believes that an improvement of labour practices would benefit not just workers, but archaeology as a whole. She argues for ways in which the field could be producing better science if archaeologists were to change their labour practices.


«This isn’t charity work,» says Mickel. «If we want to have better archaeology, if we want to know more about the past, then we need to find ways to benefit from the knowledge that local people have been hiding for decades and decades and decades from us.»


Source: Lehigh University [April 22, 2019]



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Simple sea anemones not so simple after all

The tube-dwelling anemone is an ancient sea creature that resembles a prehistoric flower. The animals live slow, long and predictable lifestyles and look fairly similar from species to species. It’d be easy to use the word «simple» when considering this relative of coral and jellyfish. But wait — not so fast.











Simple sea anemones not so simple after all
This Pachycerianthus magnus tube anemone has a surprisingly complex mitochondrial genome
[Credit: Sergio Stampar]

New research on tube anemones is challenging everything that evolutionary biologists thought they knew about sea animal genetics. The mitochondrial DNA of the tube anemone, or Ceriantharia, is a real head scratcher, from its unexpected arrangement to its previously unimagined magnitude.


Researchers, including a team from The Ohio State University, have published new findings showing that the DNA of the tube anemone does what few other species’ mitochondrial genomes have been shown to do. It defies the classic doughnut shape it «should» be in and is arranged in several fragmented pieces, the number of which vary depending on the species.


On top of that, the animal now holds the record for the largest mitochondrial genome reported to date. It contains almost 81,000 base pairs, or pieces of genetic information, according to the new study, published online in the journal Scientific Reports. Human mitochondrial DNA contains fewer than 17,000 base pairs.


«These ancient animals have simple behavior and simple anatomy, and so we’ve thought of them as fairly simple creatures until now. But their biology is quite complicated. The genomes of these tube anemones may be more dynamic than those of more-complex and more-recent animals like snails, insects and vertebrates,» said Meg Daly, a professor of evolution, ecology and organismal biology at Ohio State.


About the mitochondrial DNA that is central to this study: This isn’t the DNA most of us remember learning about in school — the instructions found within the nucleus of each cell of an organism and organized in the linear double-helix.


Rather, mitochondrial DNA is usually circular in shape and contains much less information than nuclear DNA. And it lives inside the mitochondria — double-membraned structures found in multitudes within the cell, outside the nucleus. Mitochondria are responsible for energy production, and are sometimes called the «cellular powerhouses» of living beings.


While scientists have been able to sequence the mitochondrial DNA of other similar animals, they’ve hit a roadblock with these tube anemones until now, Daly said. About two decades ago, a researcher tried to create a blueprint of the mitochondrial genome based on the theory that it would be circular.











Simple sea anemones not so simple after all
This Isarachnanthus nocturnus tube anemone has the largest animal mitochondrial genome
 reported to date, according to a team of researchers [Credit: Sergio Stampar]

«It was impossible and no one really knew why until now,» said Daly, who has made a career of studying sea anemones and their biodiversity.


Using advanced supercomputer technology, researchers examined two species of tube anemone and found that one has five linear fragments of mitochondrial DNA and the other has eight. Previously, scientists had found a linear genome in the mitochondria of the jellyfish, but the linear structure combined with the variation in size and number of fragments seen in the tube anemone is unprecedented.


«We think that the typical loop arrangement we find makes sense, because one of the advantages of the mitochondria having a circular genome is that that it replicates easily,» she said.


«We’ve thought of this loop-shaped design as something that helps the mitochondria do its job quickly and efficiently.»


Now, it is left to Daly and others who study these creatures to figure out why this might have happened from an evolutionary perspective.


«So far, there’s no rhyme or reason to the anemones having this unusual mitochondrial genome,» Daly said.


Sergio Stampar, the Brazilian researcher who led the study, said the two species examined in this research represent the largest groups of Ceriantharia.


«These results present a considerable ‘photograph’ of the group. Besides the large size of genomes, the most surprising thing that we found is the significant difference between the two species,» said Stampar, who works at the Universidade Estadual Paulista in São Paulo.


Stampar said the work raises many questions, since the presumable change from circular to linear genomes in anemones should not be a simple process. A broad discussion about the evolution of several groups of related animals called Cnidaria — which includes jellyfish, corals and sea-anemones — is imperative, he said.


It would be tempting to expect similarities in evolutionary pressures among sea animals that are all old and relatively simple in terms of appearance and function, but this new evidence is calling that into question, Daly said.


«Maybe they all started at the same place but have been subject to different evolutionary schemes and opportunities.»


Author: Misti Crane | Source: Ohio State University [April 23, 2019]



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X-ray scanning technology to unlock mysteries of rare Roman-era chainmail shirt

Researchers at EPFL have spent the past few months capturing 3D images of a Roman-era chainmail shirt using a computed tomography (CT) scanner. The piece of military armor, which dates back more than 2,000 years, is one of only a handful of similar items ever found in Europe. The twisted, corroded remains of the shirt were buried deep underground and fused with dozens of other objects that were almost impossible to tell apart using conventional investigatory techniques.











X-ray scanning technology to unlock mysteries of rare Roman-era chainmail shirt
The chainmail shirt in 3D [Credit: © PIXE/EPFL]

The EPFL researchers, working with Vaud Canton archaeologists, then came up with a full inventory of items held within the chainmail shirt. Using a 3D printer, they reproduced the items while leaving the fragile shirt – reduced by the ravages of time to a hunk of distorted metal – completely intact.
The findings will be unveiled in a special exhibition at the Cantonal Museum of Archaeology and History from 26 April to 25 August 2019.


Pick apart and reconstruct


“This research shows the potential applications of CT scanning technology in archaeology, where finds are often complex, deformed, distorted or fused,” says Pascal Turberg, who leads the ENAC Interdisciplinary Platform for X-ray micro-tomography (PIXE) at EPFL. “Using 3D imaging, we can pick these objects apart and reconstruct them.”











X-ray scanning technology to unlock mysteries of rare Roman-era chainmail shirt
The chainmail shirt in the 3D scanner [Credit: © PIXE/EPFL]

The platform’s scanners can produce images down to a resolution of just 0.5 microns – extremely useful for working out the structure of the tiniest objects.
“The complex shape of the chainmail shirt made the whole process technically challenging,” adds Turberg. “What’s more, iron has a high X-ray attenuation coefficient and generates unwanted artefacts. Working on the fragment gave us a chance to hone our 3D imaging expertise. What we learned will serve us well in the future, allowing us to scan complex materials containing metallic elements.”


A staple, two brooches, and a handle pin


The findings proved just as exciting for the archaeologists involved in the project. “This initiative was a success,” says Lionel Pernet, director of the Cantonal Museum of Archaeology and History. “With 2D X-ray images, we could only see 30 or so complete items and fragments contained inside the shirt. The 3D scans revealed more than 160!”











X-ray scanning technology to unlock mysteries of rare Roman-era chainmail shirt
A brooch [Credit: © PIXE/EPFL]

The newly discovered objects – all of which will go on display in 3D-printed form as part of the exhibition – include a furniture staple, two fibulas (Roman brooches with a spring-fastening mechanism), a cutting edge, and a pin for a cooking pot handle.


Building on success


The archaeologists are already thinking about how CT scanning technology could enhance their research in the future. They’re planning to use the scanner to peer deep inside a remarkable toolkit unearthed at Vufflens-la-Ville, and to count the tree rings inside wooden posts and statues so they can date the pieces more accurately.











X-ray scanning technology to unlock mysteries of rare Roman-era chainmail shirt
The 3D printed objects found in the chainmail shirt 
[Credit: A. Herzog/EPFL 2019]

“Scanning a funerary urn would save us a lot of time,” explains Matthieu Demierre, a lecturer at the University of Lausanne and an archaeologist at Archaeodunum, a firm that works with the cantonal archaeology office.


“Rather than working blind, we’d be able to see exactly where the bone fragments and other items are inside.”


A remarkable dig


The Roman-era chainmail shirt – an exceptionally rare find – was unearthed in 2012 at Le Mormont, a hill near La Sarraz in Vaud Canton. The archaeological site, which contains 250 separate pits, is estimated to date from around 100 B.C.


It’s been puzzling archaeologists since it was discovered during quarry expansion work in 2006. It was initially believed to be a sanctuary. But expert opinion shifted in 2011 when the contents of the pits were examined in closer detail. The finds reveal that the site was used for both religious and secular purposes.



Moreover, the presence of the chainmail shirt, complete bronze and iron cooking pots, metal containers, and other valuable objects – all buried in a short space of time – makes the site highly unusual for its era.


Archaeologists also found a large number of human remains, some showing evidence of ritual killings (aligned human and cow skulls) and others pointing to more violent deaths (severed heads and charred bodies).


Was the site a refuge for a besieged community? Could it have been a place of worship? Perhaps it was a military camp?


The researchers will only be able to solve the mystery once they’ve learned more about the items that came to rest there.


Author: Sandrine Perroud | Source: EPFL [April 23, 2019]



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Graeco-Roman era tomb discovered in Egypt’s Aswan

The Egyptian-Italian archaeological mission working at the Aga Khan Mausoleum area, on Aswan West Bank, has discovered a rock-cut tomb of a person named Tjt, that dates back to the Late Pharaonic through to the Graeco-Roman Period.











Graeco-Roman era tomb discovered in Egypt's Aswan
The AGH 26 tomb discovered in Aswan in January 2019 [Credit: Università degli Studi di Milano]

Mostafa Waziri, General Secretary of the Supreme council of Antiquities, said that inside the tomb the mission found parts of a painted wooden coffin, as well as fragments of another adorned with a complete text that includes the name of the owner and an invocation to the gods of the First Cataract Khnum, Satet and Anuket, as well as Hapy, the Nile-god.











Graeco-Roman era tomb discovered in Egypt's Aswan
Cartonnage in the form of a wide necklace [Credit: Università degli Studi di Milano]

Ayman Ashmawy, head of the antiquities ministry’s ancient Egyptian department, said that the tomb consists of a stairwayl partly flanked by sculpted blocks leading to the funerary chambers. The entrance was closed by a stone wall found in the original place that had been erected over the stairway.











Graeco-Roman era tomb discovered in Egypt's Aswan
The side room of the tomb, with the sarcophagus carved into the rock[Credit: Università degli Studi di Milano]

Patrizia Piacentini, the head of the mission, said that many amphorae and offering vases were also found, as well as a funerary structure containing four mummies and food vessels. Also found were two mummies, likely of a mother and her child, still covered by painted cartonnage.











Graeco-Roman era tomb discovered in Egypt's Aswan
Two overlapping mummies, probably of a mother and son [Credit: Università degli Studi di Milano]

A round-topped coffin was excavated from the rock floor. In the main room were around 30 mummies, including young children who were deposited in a long lateral niche.











Graeco-Roman era tomb discovered in Egypt's Aswan
Foot cover in cartonnage with golden decoration [Credit: Università degli Studi di Milano]

“Leaning against the north wall of the room was an amazing intact stretcher made of palm wood and linen strips, used by the people who deposited the mummies in the tomb,” Piacentini said.











Graeco-Roman era tomb discovered in Egypt's Aswan
Archaeologist at work inside a tomb [Credit: Università degli Studi di Milano]

At the entrance of the room were vessels containing bitumen for mummification, white cartonnage ready to be painted and a lamp.











Graeco-Roman era tomb discovered in Egypt's Aswan
Statuette of the bird Ba [Credit: Università degli Studi di Milano]

On the right and left sides of the door, many beautiful coloured and gilded cartonnages, fragments of funerary masks painted with gold and a well preserved statuette of the Ba-bird, representing the soul of the deceased, still presenting all the details of the decoration have been found.











Graeco-Roman era tomb discovered in Egypt's Aswan
Terracotta oil lamp [Credit: Università degli Studi di Milano]

The mission has mapped around 300 tombs dating from the 6th century BC to the 4th century AD, located in the area surrounding the Mausoleum of the Aga Khan, on the west bank of the Nile in Aswan. The Egyptian archaeologists had already excavated 25 tombs in the area from 2015 to 2018.


Source: Egypt. Ministry of Antiquities [April 23, 2019]



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