понедельник, 8 апреля 2019 г.

fanzelteim: Guardians in Astana Cemetery , 1915


fanzelteim:



Guardians in Astana Cemetery , 1915



Source


adirabennett2: photograph taken by @miel-et-sel at Metropolitan…


adirabennett2:



photograph taken by @miel-et-sel at Metropolitan Museum of Art exhibit on ancient China



Source


elsewheregreen: Large bronze ritual bell. Nao Late…


elsewheregreen:



Large bronze ritual bell. Nao Late Shang/Early Western Zhou Dynasty 11th-10thC BCE.



Source


Astronauts Conducting Third Spacewalk to Upgrade Station Power Systems



ISS – Expedition 59 Mission patch / EVA – Extra Vehicular Activities patch.


April 8, 2019


NASA astronauts Anne McClain and David Saint-Jacques have begun the third spacewalk in under a month on the exterior of the International Space Station. Today’s spacewalk will work to establish a redundant path of power to the Canadian-built robotic arm, known as Canadarm2, and install cables to provide for more expansive wireless communications coverage outside the orbital complex, as well as for enhanced hardwired computer network capability.


Watch the spacewalk on NASA TV and on the agency’s website: https://www.nasa.gov/nasatv



Image above:NASA astronaut Anne McClain works outside the U.S. Quest airlock during a March 22, 2019, spacewalk to upgrade the International Space Station’s power storage capacity. NASA TV.


The spacewalkers set their spacesuits to battery power this morning at 7:31 a.m. EDT then exited the Quest airlock into the vacuum of space. The team will spend about six-and-a-half hours installing truss jumpers to provide a redundant power source for the Canadarm2 robotic arm.


This is the 216th spacewalk in support of space station assembly and maintenance. McClain will be designated extravehicular crew member 1 (EV 1), wearing the suit with red stripes. Saint-Jacques will be designated extravehicular crew member 2 (EV 2), wearing the suit with no stripes.


Related links:


Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html


Quest airlock: https://www.nasa.gov/mission_pages/station/structure/elements/joint-quest-airlock


Canadarm2 robotic arm: https://www.nasa.gov/mission_pages/station/structure/elements/mobile-servicing-system.html


NASA TV: https://www.nasa.gov/nasatv


Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Image (mentioned), Text, Credits: NASA/Mark Garcia.


Best regards, Orbiter.chArchive link


2019 April 8 AZURE Vapor Tracers over Norway Image Credit &…


2019 April 8


AZURE Vapor Tracers over Norway
Image Credit & Copyright: Yang Sutie


Explanation: What’s happening in the sky? The atmosphere over northern Norway appeared quite strange for about 30 minutes last Friday when colorful clouds, dots, and plumes suddenly appeared. The colors were actually created by the NASA-funded Auroral Zone Upwelling Rocket Experiment (AZURE) which dispersed gas tracers to probe winds in Earth’s upper atmosphere. AZURE’s tracers originated from two short-lived sounding rockets launched from the Andøya Space Center in Norway. The harmless gases, trimethylaluminum and a barium/strontium mixture, were released into the ionosphere at altitudes of 115 and 250 km. The vapor trails were observed dispersing from several ground stations. Mapping how AZURE’s vapors dispersed should increase humanity’s understanding of how the solar wind transfers energy to the Earth and powers aurora.


∞ Source: apod.nasa.gov/apod/ap190408.html


historyarchaeologyartefacts: Bead bracelet of Queen Ahhotep I,…


historyarchaeologyartefacts:



Bead bracelet of Queen Ahhotep I, mother of pharaoh Ahmose I. The beads are made from gold, lapis lazuli, carnelian and faience. Egypt, 17th Dynasty ~1530 BC. [564×632]



Source


historyarchaeologyartefacts: A Roman sarcophagus depicting the…


historyarchaeologyartefacts:



A Roman sarcophagus depicting the miracles of Jesus Christ, displayed at the Archeological museum of Algiers, Algeria. [800×540]



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historyarchaeologyartefacts: The Pons Fabricius bridge across…


historyarchaeologyartefacts:



The Pons Fabricius bridge across the Tiber River in Rome, Italy, built in 62 BC. It is the oldest Roman bridge in Rome still existing in its original state. [4280×2898]



Source


Hematite on Albite with Titanite | #Geology #GeologyPage…


Hematite on Albite with Titanite | #Geology #GeologyPage #Mineral


Locality: Tormiq valley, Haramosh Mts., Skardu District, Gilgit-Baltistan, Pakistan


Size: 11.6 x 8.5 x 3.2 cm


Photo Copyright © Saphira Minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bv_CBW-lkHP/?utm_source=ig_tumblr_share&igshid=1hsb5lcvm6b6l


Fluorite, Baryte | #Geology #GeologyPage #Mineral Locality: La…


Fluorite, Baryte | #Geology #GeologyPage #Mineral


Locality: La Cabaña, Berbes Mining area, Ribadesella, Asturias, Spain.


Specimen size 35 x 20 mm


Photo Copyright © C. P. minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bv_CPhmFkvb/?utm_source=ig_tumblr_share&igshid=15mtbt32ntyl0


Vanadinite | #Geology #GeologyPage #Mineral Locality: ACF Mine…


Vanadinite | #Geology #GeologyPage #Mineral


Locality: ACF Mine (incl. Coud’a shaft; Coudia shaft), Mibladen Mining District, Midelt, Khénifra Province, Meknès-Tafilalet Region, Morocco.


Picture size 8mm


Photo Copyright © C. P. minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bv_CZmClCPd/?utm_source=ig_tumblr_share&igshid=9yxzvd5gkj5s


Blue Quartz | #Geology #GeologyPage #Mineral Locality: La…


Blue Quartz | #Geology #GeologyPage #Mineral


Locality: La Juanona quarry, Antequera, Málaga, Andalusia, Spain.


Specimen size 15 x 14 mm


Photo Copyright © C. P. minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bv_F-H4lkV3/?utm_source=ig_tumblr_share&igshid=hbe1tn5e1dkf


Quartz | #Geology #GeologyPage #Mineral Locality: Berbes,…


Quartz | #Geology #GeologyPage #Mineral


Locality: Berbes, Berbes Mining area, Ribadesella, Asturias, Spain.


Specimen size 20x18mm


Photo Copyright © C. P. minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/Bv_GLZcFbt7/?utm_source=ig_tumblr_share&igshid=zv14v17vh4g1


via-appia: Roman bread! Frescos and carbonized bread from Pompeii and Herculaneum, 1st...

via-appia:










Roman bread! Frescos and carbonized bread from Pompeii and Herculaneum, 1st century.



Source


historyarchaeologyartefacts: Sea shell of a murex bearing the…


historyarchaeologyartefacts:



Sea shell of a murex bearing the name of Rimush, king of Kish, c. 2270 BC, Louvre, traded from the Mediterranean coast where it was used by Canaanites to make a purple dye [1950×1630]



Source


historyarchaeologyartefacts: Glass cameo cup fragment, Roman…


historyarchaeologyartefacts:



Glass cameo cup fragment, Roman Empire late 1st century BCE.–mid-1st century AD[3791×3792]



Source


Global warming disrupts recovery of coral reefs

The damage caused to the Great Barrier Reef by global warming has compromised the capacity of its corals to recover, according to new research published this week in Nature.











Global warming disrupts recovery of coral reefs
Recruitment tiles made from terracotta were deployed at 15 reefs along the Great Barrier Reef to quantify
coral recruitment after the devastating back-to-back mass bleaching event in 2016-2017
[Credit: ARC CoE for Coral Reef Studies/Gergely Torda]

“Dead corals don’t make babies,” said lead author Professor Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University (JCU). “The number of new corals settling on the Great Barrier Reef declined by 89 percent following the unprecedented loss of adult corals from global warming in 2016 and 2017.”


The unique study measured how many adult corals survived along the length of the world’s largest reef system following extreme heat stress, and how many new corals they produced to replenish the Great Barrier Reef in 2018. The loss of adults resulted in a crash in coral replenishment compared to levels measured in previous years before mass coral bleaching.


“The number of coral larvae that are produced each year, and where they travel to before settling on a reef, are vital components of the resilience of the Great Barrier Reef. Our study shows that reef resilience is now severely compromised by global warming,” said co-author Professor Andrew Baird.


“The biggest decline in replenishment, a 93% drop compared to previous years, occurred in the dominant branching and table coral, Acropora. As adults these corals provide most of the three-dimensional coral habitat that support thousands of other species,” he said.


“The mix of baby coral species has shifted, and that in turn will affect the future mix of adults, as a slower than normal recovery unfolds over the next decade or longer.”


“The decline in coral recruitment matches the extent of mortality of the adult brood stock in different parts of the Reef,” added Professor Hughes. “Areas that lost the most corals had the greatest declines in replenishment.”



“We expect coral recruitment will gradually recover over the next five to ten years, as surviving corals grow and more of them reach sexual maturity, assuming of course that we don’t see another mass bleaching event in the coming decade,” he said.


So far, the Great Barrier Reef has experienced four mass bleaching events due to global warming, in 1998, 2002, and back-to-back in 2016 and 2017. Scientists predict that the gap between pairs of coral bleaching events will continue to shrink as global warming intensifies.


“It’s highly unlikely that we could escape a fifth or sixth event in the coming decade,” said co-author Professor Morgan Pratchett.


“We used to think that the Great Barrier Reef was too big to fail – until now,” he said.


“For example, when one part was damaged by a cyclone, the surrounding reefs provided the larvae for recovery. But now, the scale of severe damage from heat extremes in 2016 and 2017 was nearly 1500km–vastly larger than a cyclone track.”


Professor Pratchett added that the southern reefs that escaped the bleaching are still in very good condition, but they are too far away to replenish reefs further north.


“There’s only one way to fix this problem,” says Hughes, “and that’s to tackle the root cause of global heating by reducing net greenhouse gas emissions to zero as quickly as possible.”


Source: ARC Centre of Excellence in Coral Reef Studies [April 03, 2019]



TANN



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mostly-history: Urn Tomb (Petra, Jordan).  Built in 70 AD, this…


mostly-history:




Urn Tomb (Petra, Jordan).  Built in

70 AD, this tomb is named for the urn-shaped finial crowning its

pediment.




Source


mostly-history: Part of the talud-tablero façade of Structure…


mostly-history:





Part of the talud-tablero façade of Structure 5D-43 at Tikal

(Guatemala), with a symbol related to the Mesoamerican city of

Teotihuacán.




Chak Tok Ich’aak I, the eighth ruler of Tikal, died on January 14th,

378 AD.  This was the very same day that Sihyaj K’ak’, probably a

foreign general, arrived in the city.  It is almost certain that

Sihyaj K’ak’s “arrival” actually refers to the invasion of Tikal

by warriors from Teotihuacán, and that Chak Toik Ich’aak was

executed.  The invaders installed a new dynasty that was loyal to

Teotihuacán and its rulers.



Source


mostly-history: Ball court at Copán (Honduras), located…


mostly-history:





Ball court at Copán (Honduras), located between the Acropolis and

the Great Plaza.




Macaw-head sculptures served as markers; and the façades, doorways

and jambs of the surrounding temples were ornamented with carved

figures of the rain god Chaak and other deities.  Spectators stood on

stepped platforms to watch the ball game.  There are at least 63

carved stelae and 14 altar structures at its north end.



Source


Maelmin Prehistoric Henge and Timber Circles, Milfield, Wooler, 7.4.19.

Maelmin Prehistoric Henge and Timber Circles, Milfield, Wooler, 7.4.19.











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Global centres of unsustainable harvesting of species identified

Unsustainable harvesting, including hunting, trapping, fishing and logging, comprises one of the biggest threats to biodiversity. Yet, no previous assessment has investigated which areas are most vulnerable to this threat globally.











Global centres of unsustainable harvesting of species identified
Herd of elephants (Loxodonta africana), Addo Elephant National Park, South Africa
[Credit: Enrico Di Minin]

In a new article published in the journal Science Advances, a team of scientists has identified regions under high-intensity threat from commercial harvesting of species. On land, high-risk regions occur across all continents, but are especially concentrated in Asia and North and South America. At sea, high-risk regions are particularly concentrated in Asian seas. These hotspots cover 4.3 percent of the land and 6.1 percent of the seas.


Dr. Enrico Di Minin, a conservation scientist at the University of Helsinki, the lead author highlighted that urgent actions are needed in these centers of unsustainable harvesting to ensure that use of species is sustainable.


“We found that high-risk areas contain 82 percent of all species impacted by unsustainable harvesting, and more than 80 percent of the ranges of Critically Endangered species threatened by this threat,” says Dr. Di Minin.


“Currently, only 16 percent of these regions are covered by protected areas on land and just 6 percent at sea. Furthermore, species threatened by unsustainable harvesting are especially concentrated in areas where governance is the lowest”, he says.











Global centres of unsustainable harvesting of species identified
Helmeted hornbill from Southeast Asia is heavily hunted for its remarkable beak
[Credit: Bjorn Olesen]

Species threatened by unsustainable harvesting include highly charismatic species, such as elephant and rhinoceros, but also thousands of other less well-known species, including birds, amphibians, reptiles, fishes, plants and invertebrates. Examples include the Helmeted Hornbill from South-East Asia a bird that is heavily hunted for its remarkable beak, which is carved for decoration or used in traditional medicine. The Dama Gazelle of North Africa is threatened by uncontrolled hunting for food. And many shark species are threatened by targeted fishing and bycatch.


Prof. Thomas Brooks, chief scientist at the International Union for the Conservation of Nature (IUCN), a co-author in the article highlights the pressing threat from unsustainable harvesting.


“Unsustainable harvesting is now the most prevalent threat affecting threatened marine species and is the second most prevalent (after agriculture/aquaculture) for terrestrial and freshwater species. In this analysis, we included an extensive set of species from all comprehensively assessed groups in the IUCN Red List,” he says.


Co-author Dr. Stuart Butchart, Chief Scientist at BirdLife International, concluded: “There is an urgent need to expand and effectively manage protected areas in these hotspots, alongside broad-scale policies to tackle unsustainable fisheries, logging and hunting” added Butchart. Underpinning such efforts is the need for awareness-raising to reduce demand for threatened species, better enforcement of protective laws and strengthening compliance with trade regulation including through the Convention on International Trade in Endangered Species of Wild Fauna and Flora.


Source: University of Helsinki [April 03, 2019]



TANN



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More CO2 than ever before in 3 million years, shows unprecedented computer simulation

CO2 greenhouse gas amounts in the atmosphere are likely higher today than ever before in the past 3 million years. For the first time, a team of scientists succeeded to do a computer simulation that fits ocean floor sediment data of climate evolution over this period of time. Ice age onset, hence the start of the glacial cycles from cold to warm and back, the study reveals, was mainly triggered by a decrease of CO2-levels.











More CO2 than ever before in 3 million years, shows unprecedented computer simulation
Modelled maximum ice thickness in each grid cell (A) before and (B) after the mid-Pleistocene transition.
The dotted lines in (B) indicate the reconstructed ice extent at the last glacial maximum
[Credit: Willeit et al., 2019]

Yet today, it is the increase of greenhouse gases due to the burning of fossil fuels that is fundamentally changing our planet, the analysis further confirms. Global mean temperatures never exceeded the preindustrial levels by more than 2 degrees Celsius in the past 3 million years, the study shows – while current climate policy inaction, if continued, would exceed the 2 degrees limit already in the next 50 years.


“We know from the analysis of sediments on the bottom of our seas about past ocean temperatures and ice volumes, but so far the role of CO2 changes in shaping the glacial cycles has not been fully understood,” says Matteo Willeit of the Potsdam Institute for Climate Impact Research, lead author of the study now published in Science Advances.


“It is a breakthrough that we can now show in computer simulations that changes in CO2 levels were a main driver of the ice ages, together with variations of how the Earth’s orbits around the sun, the so-called Milankovitch cycles. These are actually not just simulations: we compared our results with the hard data from the deep sea, and they prove to be in good agreement. Our results imply a strong sensitivity of the Earth system to relatively small variations in atmospheric CO2. As fascinating as this is, it is also worrying.”


Studying Earth’s past and its natural climate variability is key to understanding possible future pathways of humanity. “It seems we’re now pushing our home planet beyond any climatic conditions experienced during the entire current geological period, the Quaternary,” says Willeit. “A period that started almost 3 million years ago and saw human civilization beginning only 11,000 years ago. So, the modern climate change we see is big, really big; even by standards of Earth history.”











More CO2 than ever before in 3 million years, shows unprecedented computer simulation
Transien modelling results: Atmospheric CO2 concentration (in pink) compared to ice core data (solid line)
and other proxies [Credit: Willeit et al., 2019]

Building on previous research at PIK, the researchers reproduced the main features of natural climate variability over the last few million years with an efficient numerical model – a computer simulation based on astronomical and geological data and algorithms representing the physics and chemistry of our planet.


The simulation was driven only by well-known changes in the ways the Earth circles the sun, the so-called orbital cycles, and different scenarios for slowly varying boundary conditions, namely CO2 outgassing from volcanoes. The study also lookedt into changes in sediment distribution of the Earth surface, since ice sheets slide more easily on gravel than on bedrock. It has also accounted for the role of atmospheric dust, which makes the ice surface darker and thereby contributes to melting.


“The fact that the model can reproduce the main features of the observed climate history gives us confidence in our general understanding of how the climate system works,” says co-author Andrey Ganopolski, author of several previous groundbreaking studies the new analysis now builds upon.


“The simulations we develop have to be simple enough to allow for thousands of calculation runs of many thousands of years, and yet have to capture the critical factors that drive our climate. This is what we have achieved. And it is confirming how outstandingly important changes in CO2 levels are for Earth’s climate.”


Source: Potsdam Institute for Climate Impact Research (PIK) [April 03, 2019]



TANN



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Gorillas gather around and groom their dead

It is now known that many animals exhibit unique behaviors around same-species corpses, ranging from removal of the bodies and burial among social insects to quiet attendance and caregiving among elephants and primates. Researchers in Rwanda and Democratic Republic of Congo have been able to take a close look at the behavioural responses to the deaths of three individuals — both known and unknown — in gorillas and have reported their findings in PeerJ – the Journal of Life and Environmental Sciences.











Gorillas gather around and groom their dead
A Grauer’s gorilla group gathers around the body of a male gorilla encountered in the forest
of Kahuzi-Biega National Park [Credit: Dian Fossey, Gorilla Fund International]

Scientists from the Dian Fossey Gorilla Fund, the University of California Davis, Uppsala University, and the Congolese Institute for the Conservation of Nature observed and filmed the behavior of mountain gorillas around the corpses of a 35-year-old dominant adult male and a 38-year-old dominant adult female from the same social group living in Volcanoes National Park, Rwanda. Both individuals had died a few hours earlier of illnesses possibly linked to their advanced age. Researchers also studied the behaviour of a group of Grauer’s gorillas who found the body of a recently deceased adult male in Kahuzi-Biega National Park, Democratic Republic of Congo.
Researchers predicted that more individuals would engage with the corpses of familiar members of their own group compared to the extra-group mature male and that individuals who shared close social relationships with the deceased would be the ones to spend the most time close to body.











Gorillas gather around and groom their dead
A juvenile mountain gorilla inspects the body of his mother for several hours after she died in
Volcanoes National Park, Rwanda [Credit: Dian Fossey, Gorilla Fund International]

To the researcher’s surprise, the behavioural responses toward the corpses in all three cases were remarkably similar. In all three cases, animals typically sat close to the body and stared at it but they also sniffed, poked, groomed and licked it.
In the two mountain gorilla cases, individuals that shared close social relationships with the deceased were the ones who spent the most time in contact with the corpse. For example, a juvenile male who had established a close relationship with Titus, the dominant mountain gorilla silverback male, after his mother left the group, remained close and often in contact with the body for two days, and slept in the same nest with it. The juvenile son of Tuck, the deceased adult female, groomed the corpse and even tried suckling from it despite having already been weaned, a behaviour that could indicate his distress near his mother’s body.


A juvenile mountain gorilla touches and grooms the body of his mother in Volcanoes National Park, Rwanda 


[Credit: Dian Fossey, Gorilla Fund International]


This work is not only of interest regarding how animals perceive and process death, but it also has important conservation implications. Close inspection of corpses can present a serious risk for disease transmission. Contacts between healthy individuals and infected corpses may be a major way through which diseases like Ebola, which have affected and killed thousands of gorillas in Central Africa, spread among gorillas.


Source: PeerJ [April 03, 2019]



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Life on Mars?

According to NASA, scientists are in agreement that there is no life on Mars. However, they continue to assess whether Mars ever had an environment capable of supporting microbial life. Now, researchers from Hungary have discovered embedded organic material in a Martian meteorite found in the late 1970s. The scientists were able to determine the presence of organic matter in mineralised form such as different forms of bacteria within the meteorite, suggesting that life could have existed on the Red Planet.











Life on Mars?
Credit: Shutterstock

Officially named ALH-77005, the Martian meteorite was found in the Allan Hills on Antarctica during the mission of the Japanese National Institute of Polar Research between 1977 and 1978. The new study “Mineralized biosignatures in ALH-77005 Shergottite – Clues to Martian Life?” published in De Gruyter’s journal Open Astronomy, by authors Ildiko Gyollai, Márta Polgári and Szaniszló Bérczi proposes the presence of active bacteria on Mars. Their research also suggests that there may have been life on other planets.


“Our work is important to a broad audience because it integrates planetary, earth, biological, chemical, and environmental sciences and will be of interest to many researchers in those fields,” explains lead author Ildiko Gyollai from HAS Research Centre for Astronomy and Earth Sciences in Budapest.


“The research will also be of interest to planetologists, experts of meteorite and astrobiology as well as researchers of the origin of life, and to the general public since it offers an example of a novel aspect of microbial mediation in stone meteorites,” Gyollai concludes.


This new research could change the examination of meteorites in the future. In light of their discovery, the authors posit that solar system materials should be studied to establish whether there is evidence of microbial forms within space rocks – and an indication that there was once life on Mars.


Source: De Gruyter [April 04, 2019]



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Heavy metal planet fragment survives destruction from dead star

A fragment of a planet that has survived the death of its star has been discovered by University of Warwick astronomers in a disc of debris formed from destroyed planets, which the star ultimately consumes.











Heavy metal planet fragment survives destruction from dead star
A planetary fragment orbits the star SDSS J122859.93+104032.9, leaving a tail of gas in its wake
[Credit: University of Warwick/Mark Garlick]

The iron and nickel rich planetesimal survived a system-wide cataclysm that followed the death of its host star, SDSS J122859.93+104032.9. Believed to have once been part of a larger planet, its survival is all the more astonishing as it orbits closer to its star than previously thought possible, going around it once every two hours.


The discovery, reported in the journal Science, is the first time that scientists have used spectroscopy to discover a solid body in orbit around a white dwarf, using subtle variations in the emitted light to identify additional gas that the planetesimal is generating.


Using the Gran Telescopio Canarias in La Palma, the scientists studied a debris disc orbiting a white dwarf 410 light years away, formed by the disruption of rocky bodies composed of elements such as iron, magnesium, silicon, and oxygen – the four key building blocks of the Earth and most rocky bodies. Within that disc they discovered a ring of gas streaming from a solid body, like a comet’s tail. This gas could either be generated by the body itself or by evaporating dust as it collides with small debris within the disc.


The astronomers estimate that this body has to be at least a kilometre in size, but could be as large as a few hundred kilometres in diameter, comparable to the largest asteroids known in our Solar System.


White dwarfs are the remains of stars like our sun that have burnt all their fuel and shed their outer layers, leaving behind a dense core which slowly cools over time. This particular star has shrunk so dramatically that the planetesimal orbits within its sun’s original radius. Evidence suggests that it was once part of a larger body further out in its solar system and is likely to have been a planet torn apart as the star began its cooling process.


Lead author Dr Christopher Manser, a Research Fellow in the Department of Physics, said: “The star would have originally been about two solar masses, but now the white dwarf is only 70% of the mass of our Sun. It is also very small – roughly the size of the Earth – and this makes the star, and in general all white dwarfs, extremely dense.


“The white dwarf’s gravity is so strong – about 100,000 times that of the Earth’s – that a typical asteroid will be ripped apart by gravitational forces if it passes too close to the white dwarf.”


Professor Boris Gaensicke, co-author from the Department of Physics, adds: “The planetesimal we have discovered is deep into the gravitational well of the white dwarf, much closer to it than we would expect to find anything still alive. That is only possible because it must be very dense and/or very likely to have internal strength that holds it together, so we propose that it is composed largely of iron and nickel.


“If it was pure iron it could survive where it lives now, but equally it could be a body that is rich in iron but with internal strength to hold it together, which is consistent with the planetesimal being a fairly massive fragment of a planet core. If correct, the original body was at least hundreds of kilometres in diameter because it is only at that point planets begin to differentiate – like oil on water – and have heavier elements sink to form a metallic core.”


The discovery offers a hint as to what planets may reside in other solar systems, and a glimpse into the future of our own.


Dr Christopher Manser said: “As stars age they grow into red giants, which ‘clean out’ much of the inner part of their planetary system. In our Solar System, the Sun will expand up to where the Earth currently orbits, and will wipe out Earth, Mercury, and Venus. Mars and beyond will survive and will move further out.


“The general consensus is that 5-6 billion years from now, our Solar System will be a white dwarf in place of the Sun, orbited by Mars, Jupiter, Saturn, the outer planets, as well as asteroids and comets. Gravitational interactions are likely to happen in such remnants of planetary systems, meaning the bigger planets can easily nudge the smaller bodies onto an orbit that takes them close to the white dwarf, where they get shredded by its enormous gravity.


“Learning about the masses of asteroids, or planetary fragments that can reach a white dwarf can tell us something about the planets that we know must be further out in this system, but we currently have no way to detect.


“Our discovery is only the second solid planetesimal found in a tight orbit around a white dwarf, with the previous one found because debris passing in front of the star blocked some of its light – that is the “transit method” widely used to discover exoplanets around Sun-like stars. To find such transits, the geometry under which we view them has to be very finely tuned, which means that each system observed for several hours mostly leads to nothing. The spectroscopic method we developed in this research can detect close-in planetesimals without the need for a specific alignment. We already know of several other systems with debris discs very similar to SDSS J122859.93+104032.9, which we will study next. We are confident that we will discover additional planetesimals orbiting white dwarfs, which will then allow us to learn more about their general properties.”


Source: University of Warwick [April 04, 2019]




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Repatriating two rare looted ancient Greek vessels

Standing at just under 60 centimeters in height, two 4th century BC marble vessels – a funerary lekythos and a loutrophoros – that the Greek state is in negotiations to repatriate from Switzerland have traveled across four countries, changing hands dozens of times between mediators, merchants, art collectors and even police authorities. They were photographed, sold, confiscated and sold again, leaving a trail – however faint – of shady dealings.











Repatriating two rare looted ancient Greek vessels
The two 4th century BC marble vessels – a funerary lekythos and a loutrophoros – have traveled across four countries,
changing hands dozens of times between mediators, merchants, art collectors and even police authorities
[Credit: Kathimerini]

The repatriation drive started in October 2017 when a student of forensic archaeologist Christos Tsirogiannis at Cambridge University – who is known for his work hunting down antiquities smuggling rackets – was attending the Galleries at Frieze Masters exhibition in London and spotted the two Attic vessels at the stall of Swiss art dealer Jean-David Cahn, a specialist in Greek and Roman antiquities.


The student photographed the pieces and sent the images to Tsirogiannis, knowing he would be interested. Tsirogiannis started comparing the photographs with images in an album of antiquities suspected of having been stolen while also studying collection histories in order to ascertain their provenance. The evidence he uncovered pointed to some shady dealings in their past.


Tsirogiannis told Kathimerini recently that he found Polaroid shots of both vessels from the seized archives of notorious Italian antiquities smuggler Gianfranco Becchina. The lekythos depicts the deceased and his family, and bears an inscription with their names, details that had been noted by the smugglers in red marker on the Polaroid to underscore the piece’s authenticity.


As soon as he identified the vessels, the Greek investigator informed Interpol of his discovery. The objects were seized from the Swiss art collector, paving the way for the battle for their return to Greece.


The case was assigned to Ilias Bissias, a lawyer based in Athens and Zurich who has successfully represented the Greek state in similar claims. He declined to comment as the case is ongoing, but did note that it is a crucial juncture.


The preliminary investigation by the Greek judicial authorities into the two vessels’ provenance is also under way.


What is already known, however, is that two people who have fallen foul of Greek justice in the past are involved in the case of the two vessels. Becchina was convicted in Greece in 2017 and 2018 to a respective 11 and seven years in prison for accepting four Early Christian murals that were stolen from a church on the island of Euboea (Evia) and for embezzlement. Cahn, meanwhile, has twice reached a settlement with the Greek state for the return of ancient objects that were illegally smuggled out of the country – in both these repatriations the Greek state was represented by Bissias.


The objects in question are a 1st century AD headless statue of Apollo Lyceus that was stolen along with another nine artifacts from Gortyn on Crete. It is a replica of an original statue that has been attributed to Praxiteles or his school and had been tracked to Switzerland 16 years after being stolen from Greece.


Cahn had sold it to a private buyer but had not yet delivered it when he was approached by authorities and negotiated a deal to return it in 2007. Then, in 2008, he returned a 4th century BC marble lekythos that he had put up for auction at an international art fair in Maastricht before it was identified as the object of antiquities smuggling.


The Becchina archive


In the current case of the two marble vessels, Cahn is acting as the mediator representing the Swiss canton of Basel. That story dates back to 2002 and a police raid on Becchina’s gallery in Basel, where authorities seized and photographed more than 5,800 objects of suspect provenance, most of which were repatriated in the years that followed to Italy.


In 2006, the Culture Ministry in Athens received five CDs with photographs of objects that were suspected of having come from Greece from the Becchina archive, which to this day serves as an important means of identifying items that may have been trafficked.


In 2011, the Italian authorities returned 19 objects that had been sent for repatriation there back to the Swiss. These included the two Greek marble vessels, which were handed to Cahn by Swiss authorities so he could sell them in order to settle a part of Becchina’s debts to the state.


Bilateral agreement


What is odd about this particular case is that the two vessels were passed between the Italian and Swiss authorities, without the Greek authorities being informed earlier, even though Becchina was involved.


For his part, Cahn issued a statement on his website saying he had received assurances that the two objects had been acquired legally. He claims the Swiss authorities had been given the green light to sell the vessels by a legal expert at the University of Geneva, though he did not provide a name. Cahn also claimed he checked that the two vessels did not appear on the Art Loss Register database of stolen art and found no mention of them.


Apart from whatever legal questions may arise from the matter, the case also has a diplomatic aspect, as Greece and Switzerland signed an agreement for the repatriation of cultural goods in 2007.


Author: Yiannis Papadopoulos | Source: Kathimerini [April 06, 2019]



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