воскресенье, 15 июля 2018 г.

First global maps of Pluto and Charon from NASA’s New Horizons mission published

Until 2015, it was not known whether Pluto or its largest moon, Charon, had mountains or valleys or even impact craters. After the spectacular success of New Horizons in July 2015, scientists were amazed at the towering peaks and deep valleys that were revealed in the returned data. Now, thanks to the efforts of the New Horizons team, the first official validated global map and topographic maps of these two bodies have been published and are available to all. The maps and the process of creating them are described in two new research articles published in the journal Icarus.

First global maps of Pluto and Charon from NASA’s New Horizons mission published
Mountain ridges and volcanic plains on Pluto’s moon, Charon [Credit: USRA]

To create the maps, New Horizons researchers, led by Universities Space Research Association (USRA) Senior Staff Scientist, Paul Schenk, at the Lunar and Planetary Institute, registered all the images from the Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) systems together and assembled the mosaics. This was a labor-intensive effort requiring detailed alignment of surface features in overlapping images.

Digital analysis of stereo images obtained by both cameras were used to create topographic maps for each region; these were then assembled into integrated topographic maps for each body. These new maps of Pluto and Charon were produced painstakingly over a two-year period as data were slowly transmitted to Earth from the New Horizons spacecraft. The quality of geographically and topographically accurate maps improved with each new batch of images that were returned to Earth.

“This was one of the most complex yet most exciting planetary mapping projects I’ve had the pleasure to be involved with. Every time new images came down, something new would be revealed,” says Schenk. “The first thing we had to do was understand the behavior of two different imaging systems in order to derive reliable topographic maps.” While preliminary maps of these bodies have been released before, these final, validated maps represent the best current understanding of the surfaces of these two important bodies.

First global maps of Pluto and Charon from NASA’s New Horizons mission published
This view shows Pluto’s highest mountains, which rise 3 to 6 kilometers above the smooth nitrogen-ice 
plains of Sputnik Planitia. New maps of Pluto’s topography show more details of familiar
 landscapes like this one [Credit: USRA]

The validated global cartographic and topographic maps show the best resolution for each area illuminated by the Sun, and their elevations. These maps reveal a rich variety of landforms on both Pluto and Charon. The topographic maps confirm that the highest known mountains on Pluto are the Tenzing Montes range, which formed along the southwestern margins of the frozen nitrogen ice sheet of Sputnik Planitia. These steep-sided icy peaks have slopes of 40° or more and rise several kilometers above the floor of Sputnik Planitia.

The highest peak rises approximately 6 kilometers (3.7 miles) above the base of the range, comparable to base-to-crest heights of Denali in Alaska, and Kilimanjaro in Kenya. Pluto’s mountains must be composed of stiff water ice in order to maintain their heights, as the more volatile ices observed on Pluto, including methane and nitrogen ice, would be too weak and the mountains would collapse.

The topographic maps also reveal large-scale features that are not obvious in the global mosaic map. The ice sheet within the 1000-kilometer (625-mile) wide Sputnik Planitia is on average 2.5 kilometers (1.5 miles) deep while the outer edges of the ice sheet lie an even deeper 3.5 km (or 2.2. miles) below Pluto’s mean elevation, or ‘sea level’ surface. While most of the ice sheet is relatively flat, these outer edges of Sputnik Planitia are the lowest known areas on Pluto, all features that are evident only in the stereo images and elevation maps.

First global maps of Pluto and Charon from NASA’s New Horizons mission published
This subset of the new Pluto map (bottom) shows part of a long series of ridges and troughs that extends over 
at least 3,200 kilometers. Astronomers aren’t sure how it formed. The digital elevation model (top) shows 
the same area. White arrows highlight the edge of Sputnik Planitia, the planet’s heart-shaped plains 
of nitrogen ice [Credit: P.M. Schenk et al./Icarus 2018]

The topographic maps also reveal the existence of a global-scale deeply eroded ridge-and-trough system more than 3000 kilometers (or 1864 miles) long, trending from north-to-south near the western edge of Sputnik Planitia. This feature is the longest known on Pluto and indicates that extensive fracturing occurred in the distant past. Why such fracturing occurred only along this linear band is not well understood.

The principal investigator of the New Horizons mission, Alan Stern, of the Southwest Research Institute noted, “Pluto’s degree of topographic relief on the hemisphere we explored with New Horizons is truly amazing, I can’t wait to see the other side of Pluto revealed in detail by a future mission to orbit the planet.”

On Charon the topographic maps also reveal deep depressions near the north pole that are ~14 kilometers (8.7 miles) deep, deeper than the Marianas Trench on Earth. The equatorial troughs that form the boundary between the northern and southern plains on Charon also feature high relief of ~8 kilometers. The mapping of fractured northern terrains and tilted crustal blocks along this boundary could be due to cryovolcanic resurfacing, perhaps triggered by the foundering of large crustal blocks into the deep interior of Charon.

“These and other features make Charon the most rugged mid-sized icy satellites other than Saturn’s high-contrast moon Iapetus,” says Ross Beyer, Research Scientist at the SETI Institute in California with additional help from the United States Geological Survey (USGS), who assisted in the mapping efforts and is a co-author on the two Icarus articles. The rugged relief also indicates that Charon retains much of its original topography caused by its history of fracturing and surface disruption.

The global image and topography maps of Pluto and Charon have been archived into the Planetary Data System and will be available for use by the scientific community and the public.

Source: USRA [July 12, 2018]




Breakthrough in the search for cosmic particle accelerators

Using an internationally organised astronomical dragnet, scientist have for the first time located a source of high-energy cosmic neutrinos, ghostly elementary particles that travel billions of light years through the universe, flying unaffected through stars, planets and entire galaxies. The joint observation campaign was triggered by a single neutrino that had been recorded by the IceCube neutrino telescope at the South Pole, on 22 September 2017. Telescopes on earth and in space were able to determine that the exotic particle had originated in a galaxy over three billion light years away, in the constellation of Orion, where a gigantic black hole serves as a natural particle accelerator. Scientists from the 18 different observatories involved are presenting their findings in the journal Science. Furthermore, a second analysis, also published in Science, shows that other neutrinos previously recorded by IceCube came from the same source.

Breakthrough in the search for cosmic particle accelerators
Artist’s impression of the active galactic nucleus. The supermassive black hole at the center of the accretion disk
sends a narrow high-energy jet of matter into space, perpendicular to the disc
[Credit: DESY, Science Communication Lab]

The observation campaign, in which research scientists from Germany played a key role, is a decisive step towards solving a riddle that has been puzzling scientists for over 100 years, namely that of the precise origins of so-called cosmic rays, high-energy subatomic particles that are constantly bombarding Earth’s atmosphere. “This is a milestone for the budding field of neutrino astronomy. We are opening a new window into the high-energy universe,” says Marek Kowalski, the head of Neutrino Astronomy at DESY, a research centre of the Helmholtz Association, and a researcher at the Humboldt University in Berlin. “The concerted observational campaign using instruments located all over the globe is also a significant achievement for the field of multi-messenger astronomy, that is the investigation of cosmic objects using different messengers, such as electromagnetic radiation, gravitational waves and neutrinos.”

Messengers from the high-energy universe

One way in which scientists expect energetic neutrinos to be created is as a sort of by-product of cosmic rays, that are expected to be produced in cosmic particle accelerators, such as the vortex of matter created by supermassive black holes or exploding stars. However, unlike the electrically charged particles of cosmic rays, neutrinos are electrically neutral and therefore not deflected by cosmic magnetic fields as they travel through space, meaning that the direction from which they arrive points straight back at their actual source. Also, neutrinos are scarcely absorbed. “Observing cosmic neutrinos gives us a glimpse of processes that are opaque to electromagnetic radiation,” says Klaus Helbing from the Bergische University of Wuppertal, spokesperson for the German IceCube network.””Cosmic neutrinos are messengers from the high-energy universe.”

Breakthrough in the search for cosmic particle accelerators
The IceCube Neutrino Observatory encompasses a cubic kilometer of pristine ice deep below Antarctica’s surface
and next to the NSF Amundsen-Scott South Pole Station. In this illustration, based on an aerial view near the
South Pole, an artistic rendering of the IceCube detector shows the interaction of a neutrino with a molecule
of ice. The display pattern is how scientists represent data on recorded light. Every coloured circle represents
light collected by one of the IceCube sensors. The color gradient, from red to green/blue,
shows the time sequence [Credit: IceCube Collaboration/NSF]

Demonstrating the presence of neutrinos is extremely complicated, however, because most of the ghostly particles travel right through the entire Earth without leaving a trace. Only on very rare occasions does a neutrino interact with its surroundings. It therefore takes huge detectors in order to capture at least a few of these rare reactions. For the IceCube detector, an international consortium of scientists headed by the University of Wisconsin in Madison (USA) drilled 86 holes into the Antarctic ice, each 2500 metres deep. Into these holes they lowered 5160 light sensors, spread out over a total volume of one cubic kilometre. The sensors register the tiny flashes of light that are produced during the rare neutrino interactions in the transparent ice.

Five years ago, IceCube furnished the first evidence of high-energy neutrinos from the depths of outer space. However, these neutrinos appeared to be arriving from random directions across the sky. “Up to this day, we didn’t know where they originated,” says Elisa Resconi from the Technical University of Munich, whose group contributed crucially to the findings. “Through the neutrino recorded on 22 September, we have now managed to identify a first source.”

From radio waves to gamma radiation

The energy of the neutrino in question was around 300 tera-electronvolts, more than 40 times that of the protons produced in the world’s largest particle accelerator, the Large Hadron Collider at the European accelerator facility CERN outside Geneva. Within minutes of recording the neutrino, the IceCube detector automatically alerted numerous other astronomical observatories. A large number of these then scrutinised the region in which the high-energy neutrino had originated, scanning the entire electromagnetic spectrum: from high-energy gamma- and X-rays, through visible light, to radio waves. Sure enough, they were able for the first time to assign a celestial object to the direction from which a high-energy cosmic neutrino had arrived.

On Sept. 22, 2017, NSF’s IceCube Neutrino Observatory alerted the international astronomy community that a 
high-energy neutrino had passed through the Earth. That notification set in motion follow-on observations
 from nearly two dozen observatories on Earth and in space, ultimately confirming the source of the
 neutrino, a first for science. This brief video explains the discovery and how it has helped 
resolve a 100-year mystery about the sources of high-energy cosmic rays [Credit: NSF]

“In our case, we saw an active galaxy, which is a large galaxy containing a gigantic black hole at its centre,” explains Kowalski. Huge “jets” shoot out into space at right angles to the massive vortex that sucks matter into the black hole. Astrophysicists have long suspected that these jets generate a substantial proportion of cosmic particle radiation. “Now we have found key evidence supporting this assumption,” Resconi emphasises.

The active galaxy that has now been identified is a so-called blazar, an active galaxy whose jet points precisely in our direction. Using software developed by DESY researchers, the gamma-ray satellite Fermi, operated by the US space agency NASA, had already registered a dramatic increase in the activity of this blazar, whose catalogue number is TXS 0506+056, around 22 September. Now, an earthbound gamma-ray telescope also recorded a signal from it. “In the follow-up observation of the neutrino, we were able to observe the blazar in the range of very high-energy gamma radiation too, using the MAGIC telescope system on the Canary Island La Palma,” says DESY’s Elisa Bernardini, who coordinates the MAGIC observations. “The gamma-rays are closest in energy to neutrinos and therefore play a crucial role in determining the mechanism by which the neutrinos are created.” The programme for the efficient follow-up observation of neutrinos using gamma-ray telescopes was developed by Bernardini’s group.

The NASA X-ray satellites Swift and NuSTAR also registered the eruption of the blazar, and the gamma-ray telescopes H.E.S.S., HAWC and VERITAS as well as the gamma-ray and X-ray satellites AGILE, belonging to the Italian Space Agency ASI, and Integral, belonging to the European Space Agency ESA, all took part in the follow-up observations. All in all, seven optical observatories (the ASAS-SN, Liverpool, Kanata, Kiso Schmidt, SALT and Subaru telescopes, as well as the Very Large Telescope VLT of the European Southern Observatory, ESO) observed the active galaxy, and the Karl G. Jansky Very Large Array (VLA) studied its activity in the radio spectrum. This led to a comprehensive picture of the radiation emitted by this blazar, all the way from radio waves to gamma-rays carrying up to 100 billion times as much energy.

Search in archives reveals further neutrinos

A worldwide team of scientists from all the groups involved worked flat out, conducting a complicated statistical analysis to determine whether the correlation between the neutrino and the gamma-ray observations was perhaps just a coincidence. “We calculated that the probability of it being a mere coincidence was around 1 in 1000,” explains DESY’s Anna Franckowiak, who was in charge of the statistical analysis of the various different data sets. This may not sound very large, but it is not small enough to quell the professional scepticism of physicists.

Featuring IceCube’s PI and spokesperson along with other experts from the collaboration, this video explains the 
observations that led to the identification of the first source of high-energy neutrinos and cosmic rays. These 
results help us answer a one-hundred-year-old riddle: where and how does nature accelerate particles to the
 highest energies ever detected? [Credit: IceCube Collaboration/NSF]

A second line of investigation rectified this. The IceCube researchers searched through their data from the past years for possible previous measurements of neutrinos coming from the direction of the blazar that had now been identified. And they did indeed find a distinct surplus of more than a dozen of the ghost particles arriving from the direction of TXS 0506+056 during the time between September 2014 and March 2015, as they are reporting in a second paper published in the same edition of Science. The likelihood of this excess being a mere statistical outlier is estimated at 1 in 5000, “a number that makes you prick up your ears,” says Christopher Wiebusch from RWTH Aachen, whose group had already noted the hint of excess neutrinos from the direction of TXS 0506+056 in an earlier analysis. “The data also allows us to make a first estimate of the neutrino flux from this source.” Together with the single event of September 2017, the IceCube data now provides the best experimental evidence to date that active galaxies are in fact sources of high-energy cosmic neutrinos.

“We now have a better understanding of what we should be looking for. This means that we can in future track down such sources more specifically,” says Elisa Resconi. And Marek Kowalski adds, “Since neutrinos are a sort of by-product of the charged particles in cosmic rays, our observation implies that active galaxies are also accelerators of cosmic ray particles. More than a century after the discovery of cosmic rays by Victor Hess in 1912, the IceCube findings have therefore for the first time located a concrete extragalactic source of these high-energy particles.”

Sources: Deutsches Elektronen-Synchrotron DESY [July 12, 2018]




Geological records reveal sea-level rise threatens UK salt marshes, study says

Sea-level rise will endanger valuable salt marshes across the United Kingdom by 2100 if greenhouse gas emissions continue unabated, according to an international study co-authored by a Rutgers University-New Brunswick professor.

Geological records reveal sea-level rise threatens UK salt marshes, study says
A salt marsh in Tees Estuary, England, showing signs of erosion [Credit: Matthew Brain]

Moreover, salt marshes in southern and eastern England face a high risk of loss by 2040, according to the study published in Nature Communications.

The study is the first to estimate salt-marsh vulnerability using the geological record of past losses in response to sea-level change.

An international team of scientists, led by former Rutgers-New Brunswick Professor Benjamin Horton – now acting chair and a professor at the Asian School of the Environment at Nanyang Technological University – found that rising sea levels in the past led to increased waterlogging of the salt marshes in the region, killing the vegetation that protects them from erosion. The study is based on data from 800 salt-marsh soil cores. Tidal marshes rank among Earth’s most vulnerable ecosystems.

“By 2100, if we continue upon a high-emissions trajectory, essentially all British salt marshes will face a high risk of loss. Reducing emissions significantly increase the odds that salt marshes will survive,” said study co-author Robert E. Kopp, a professor in the Department of Earth and Planetary Sciences at Rutgers-New Brunswick and director of the Rutgers Institute of Earth, Ocean, and Atmospheric Sciences. Kopp led the development of the study’s sea-level rise projections.

“Salt marshes, also called coastal wetlands, are important because they provide vital ecosystem services,” said Horton. “They act as a buffer against coastal storms to protect the mainland and a filter for pollutants to decontaminate our fresh water. We also lose an important biodiversity hotspot. Salt marshes are important transitional habitats between the ocean and the land, and a nursery area for fish, crustacea, and insects. The take-home point from this paper is how quickly we are going to lose these ecologically and economically important coastal areas in the 21st century.”

While the study looks at UK salt marshes, the counterpart in tropical environments such as Singapore are mangroves, which are just as vulnerable to sea-level rise as salt marshes.

“What is unknown is the tipping point that will cause a disintegration of mangroves to Singapore and elsewhere in Southeast Asia,” Horton said. “We are currently collecting data to address the future vulnerability of mangroves to sea-level rise.”

Source: Rutgers University [July 12, 2018]




Roman, Byzantine chambers discovered in Alexandria

A number of Roman and Byzantine chambers have been uncovered during rescue excavations carried out in Mitt Abu Al-Kom at Marya site in Alexandria.

Roman, Byzantine chambers discovered in Alexandria
Credit: Ministry of Antiquities

Mostafa Waziri, secretary general of the Supreme Council of Antiquities, explained that one of the discovered chambers has walls composed of huge stone blocks at right angles with burry remains of Roman structures, while the second chamber has marble columns smoothly carved in Doric order Roman style, in addition to a large number of coins.

Roman, Byzantine chambers discovered in Alexandria

Roman, Byzantine chambers discovered in Alexandria
Credit: Ministry of Antiquities

The rest of the chambers have Byzantine walls, which contain blocks of stone of irregular and unequal sizes with spaces filled with weak Byzantine mortar, much of which deteriorated. Another room with a tiled floor has a column bearing foliage decoration.

Roman, Byzantine chambers discovered in Alexandria

Roman, Byzantine chambers discovered in Alexandria
Credit: Ministry of Antiquities

Nadia Kheidr, head of the Central Department of Antiquities of Lower Egypt, said that a number of lamps decorated with crosses and palm leaves were found, along with dishes and two large water jars, all of them in good condition, as well as a large number of fragments of pottery.

Author: Nevine El-Aref | Source: Ahram Online [July 12, 2018]




Study finds 84 highly endangered Amur leopards remain in China and Russia

Scientists estimate there are only 84 remaining highly endangered Amur leopards (Panthera pardus orientalis) remaining in the wild across its current range along the southernmost border of Primorskii Province in Russia and Jilin Province of China.

Study finds 84 highly endangered Amur leopards remain in China and Russia
Scientists estimate there are only 84 remaining highly endangered Amur leopards (Panthera pardus orientalis)
 remaining in the wild across its current range along the southernmost border of Primorskii Province
 in Russia and Jilin Province of China [Credit: Emmanual Rondeau]

This new estimate of the Amur leopard population was recently reported in the scientific journal, Conservation Letters by scientists from China, Russia, and the United States. The scientists combined forces to collate information from camera traps on both sides of the border of China and Russia to derive the estimate. Because there are no records of leopards in other parts of its former range, this estimate represents the total global population of this subspecies in the wild.

Although numbers are small, previous estimates in Russia were even less, ranging from 25 to 50 individuals. However, those surveys, based on tracks left in the snow, were extremely difficult to interpret due to the unclear relationship between numbers of tracks and number of individuals. With camera traps, each individual can be identified by its unique spot pattern, providing a much more precise estimate.

Combining data from both countries increased precision of the estimate, and provided greater accuracy. Surprisingly, about one-third of the leopards were photographed on both sides of the Sino-Russian border.

Anya Vitkalova, a biologist at Land of the Leopard National Park in Russia, and one of the two lead authors of the publication said: “We knew that leopards moved across the border, but only by combining data were we able to understand how much movement there really is.”

Despite the movement, there were differences in population dynamics in Russia versus China. Leopards are currently recolonizing habitat in China by dispersing from the Russian side, where leopard numbers appear to be close to the maximum that can be supported.

Because of these transboundary movements of leopards, simply adding results from both sides would have greatly exaggerated the estimate.

Dale Miquelle, a co-author and Tiger Program Coordinator for the Wildlife Conservation Society noted: “This first rigorous estimate of the global population of the Amur leopard represents an excellent example of the value of international collaboration. The trust and goodwill generated by this joint effort lays the foundation for future transboundary conservation actions.”

Source: Wildlife Conservation Society [July 13, 2018]




Roman observation towers unearthed in Turkey’s Konya

A hundred border monitoring towers have been discovered in the Bozdağ National Park in the Central Anatolian province of Konya’s Karatay district. The towers were built during the Roman Empire to serve as border outposts and were also used by the Byzantines.

Roman observation towers unearthed in Turkey's Konya
The area of the towers was used to house military garrisons by the Romans and was the
seat of an Armenian diocese in the Byzantine period [Credit: AA]

The tower remnants have been unearthed by a team of eight people headed by Selçuk University (SU) Conservation and Restoration of Movable Cultural Heritage Department President İlker Işık.

Speaking to the Anadolu Agency, Işık said the Bozdağ National Park had been an important field with ancient sites around it.

“We have found 100 towers, where one or two guards could keep watch. We have photographed 42 of them and we will work on the other towers in the coming days,” said Işık, adding they had examined an area of 3,500 hectares in two years.

He also noted the towers lost their function after the Roman and Byzantine eras and were used “as sheep pens and granaries” during the Seljuk period.

Source: Hurriyet Daily News [July 13, 2018]




HiPOD (15 July 2018): Cored Island   – This channel may have…

HiPOD (15 July 2018): Cored Island

   – This channel may have been used by both lava and water. One of the processes produced a crater-cored island and later, the downstream side was eroded away, leaving knobs and an inverted streamlined form.

NASA/JPL/University of Arizona (313 km above the surface. Black and white is less than 5 km across; enhanced color is less than 1 km)


Road workers discover ancient sarcophagus in northern Turkey

An ancient sarcophagus has been discovered during road works in northern Turkey’s Karabük province, according to reports.

Road workers discover ancient sarcophagus in northern Turkey
IHA/DHA Photos

Fatih Demirel, the district governor of Yenice, told Anadolu Agency (AA) that the sarcophagus is estimated to be about 1,800 years old. Since the discovery on Sunday, road works have been stopped and local security forces have been watching the area non-stop.

Several tear bottles dating back to the Roman era, along with many other historical artefacts were found in the sarcophagus, experts said.

Source: Daily Sabah [July 10, 2018]




Archaeology team set to study pre-contact Inuit winter village

For more than 300 years, Kivalekh was an Inuit winter village in the Okak Islands, located approximately 100 kilometres north of Nain.

Archaeology team set to study pre-contact Inuit winter village
A midden test from Peter Whitbridge’s 2016 field work at Johannes Point (Hebron Fiord), northern Labrador,
similar to work the Memorial University archaeologist plans to do at the Inuit winter village Kivalekh,
in the Okak Islands this summer [Credit: The Telegram]

“As at the winter village of Uivakh on the mainland just north of Okak, residents of Kivalekh probably hunted bowhead whales and harp seals in the fall, and ringed seal throughout the winter,” said Peter Whitbridge, a Memorial University (MUN) archaeologist. “Although there is a large number of winter houses (at least 50) at Kivalekh, until we investigate further it is impossible to estimate how many might have been occupied at any one time. Moravians counted about 120 people in six houses there in 1773.”

Further investigation, designed to promote conservation and commemorate the 1918-19 Spanish influenza epidemic that decimated the community, is scheduled for this summer.

Whitbridge, with a team of four assistants, plans to spend the last three weeks of July in the field. They will be working to build on research conducted between 1974 and 1984 that focussed more on pre-Inuit (Dorset) occupation of the area and which, Whitbridge said, produced a map that is not very accurate in light of modern satellite imagery.

The 2018 field work will take advantage of the latest technology.

“This summer we plan to carefully survey the site with a total station (an electronic optical surveying instrument), as well as generating an aerial photo mosaic and 3D model by taking photographs with a drone,” Whitbridge explained. “We will also survey the surrounding area for additional sites, and excavate small tests in midden (historic domestic waste) areas to generate datable organic samples.”

Whitbridge initiated drone mapping in Labrador in 2016 at Johannes Point (Hebron Fiord). He plans to expand the program in line with what is happening generally in the discipline of archaeology.

“I think we can produce an extremely rich body of maps and imagery of northern Labrador sites that will be of great value, not only to other archaeologists, but to Labrador communities, government land managers, other researchers and the tourism industry,” he said.

Whitbridge said they are going back to northern Labrador with a more powerful drone and better quality camera than in 2016.

“I hope we will raise the bar on the kind of aerial document it is possible to produce in a relatively short time,” he said. “There is a wider move in archaeology to replace time-consuming ground survey with high resolution aerial mapping.”

Whitbridge expects this summer’s project will provide a better idea of the potential of the newest drones and drone cameras to dramatically speed up the mapping process —from weeks to days — especially in a wilderness field setting where time on the ground is extremely costly.

Author: Thom Barker | Source: The Telegram [July 10, 2018]




Contents of Roman coffin discovered in Southwark finally revealed

A massive stone coffin excavated last year could have contained nothing but 2,000 years of mud. But after a year of very, very careful brushing, trowelling and prodding, archaeologists have revealed the contents of the sarcophagus found last July in what is now Harper Road, Southwark.

Contents of Roman coffin discovered in Southwark finally revealed
Archaeologists prepare to lift the lid of an ancient Roman sarcophagus dating from the 4th century found
on a building site in Swan Street, Southwark, London [Credit: Lauren Hurley/PA]

It was interred by toga-wearers during the Roman occupation, from 43-410AD and discovered by scientists helping to ensure a development did not stomp on vital pieces of our history – and that is exactly what they found – lots of bits. It was painstakingly uncovered and carefully removed over the course of several weeks.

The stone edifice itself is the prize exhibit in the Roman Dead show at the Museum of London Docklands in West India Quay until October, but the material it contained was a mystery for several months after it was discovered. The show is the first exhibition of its kind to explore the beliefs, rituals, deaths and burials in ancient London.

Jackie Keily, senior curator at the Museum of London who is working on the Roman Dead exhibition, said in May: “The sarcophagus was successfully and professionally lifted from its site in Southwark and is now at the Museum of London Archaeological Archive. “It is extremely fragile and the content is in the process of being analysed. Due to the fragility of the structure this is a slow procedure and we are yet to determine what could be inside.”

But the museum has now revealed it contained:

– A woman’s skeleton – carbon dating of her bones showed that she had been buried between AD 86 and 328, although other dating evidence from the site suggests a burial date of AD 275-328.

– Gold fragment, AD 275-328. The soil inside the coffin was carefully excavated and sieved. A tiny scrap of gold was found, which may be the remains of an earring, perhaps worn by the woman or buried alongside her

– Intaglio, AD 100-200. This tiny gemstone is made from jasper and is carved with a satyr and would have originally been set into a ring. The gemstone was already old when buried and was likely a family heirloom.

Contents of Roman coffin discovered in Southwark finally revealed
Removing the lid of Roman sarcophagus found in Borough Market, London
[Credit: Lauren Hurley/PA]

Curators also found evidence to suggest that the vessel was robbed of its treasures in antiquity.

Approximately a third of the remains are unaccounted for, and a crack in the heavy lid of the sarcophagus points towards a grave robbery in the 16th century.

The structure was an exceptional find for London, where only two similar late Roman sarcophagi have been discovered in their original place of burial in recent years: one from St Martin-in-the Fields near Trafalgar Square (2006) and one from Spitalfields in 1999. The excavation, which began in January last year, revealed a wide robber trench around the coffin and found that the lid had been moved, suggesting the coffin had been disturbed and robbed in the past. The archaeologists hoped at the time that only the precious items were removed, and the less valuable artefacts, such as the body itself, still remain within.

The skeleton survived within the sarcophagus – so it could make a huge contribution to current archaeological research.

Roman London had immigrants from all over the empire and adding to the mix of different religious practices and beliefs. Exotic grave goods from across the Roman Empire are just some of more than 200 objects on display at the exhibition, which examines important questions about death in Roman London whilst exploring the latest research into beliefs around afterlife and funerary practice.

The Harper Road excavation is just one of a string of archaeological projects currently running across Southwark.

As well as showcasing exciting artefacts from Roman London the exhibition will examine the science behind the study of ancient human remains and highlight the rites and rituals surrounding death in Roman London.

Author: Howard Smith | Source: London News Online [July 10, 2018]




Portugal’s Roman Villa da Corte reveals its secrets

The Roman Villa of da Corte is the first complex built in the Roman period located in São Bartolomeu de Messines, close to the city of Silves (Algarve), and the most significant structure from the Roman period excavated until now in southern Portugal.

Portugal's Roman Villa da Corte reveals its secrets
Reconstruction of the Roman villa in São Bartolomeu de Messines[Credit: Museu Municipal de Arqueologia de Silves]

It was found in 2005 by the technician of the Municipal Chamber of Silves, Jorge Correia, and excavated between 2009 and 2014 by a team from the University of Jena (Germany), in collaboration with the regional government of Silves (which supported most of the expenses) and the General Directorate of Cultural Heritage.

Now an exhibition at the Museu Municipal de Arqueologia de Silves reveals what that villa was like, who lived there and how those occupants lived.

Portugal's Roman Villa da Corte reveals its secrets
Reconstruction of the Roman villa in São Bartolomeu de Messines[Credit: Museu Municipal de Arqueologia de Silves]

Although the villa was rebuilt following a devastating earthquake in 300 AD, it was originally constructed in the first half of the first century. It was finally abandoned during the Islamic conquest in the ninth century.

The villa was home to people of the upper middle class, with a high and evident prosperity, as the imported objects from Greece and South Italy testify.

Portugal's Roman Villa da Corte reveals its secrets
Excavations of the Roman Villa in São Bartolomeu de Messines
[Credit: Dennis Graen/FSU]

Of large dimensions, the villa, in addition to the area of individual living spaces, had a terrace and a bathroom area, fed by a water cistern linked to a supply source. The remains of marble and mosaic stuccoes and floorings are another of the villa’s unique features. It was also equipped with a winepress, kiln and stables. Materials linked to the production of textiles indicate that this was one of the activities carried out in the villa.

The exhibition presents many objects linked to the daily life of the inhabitants of the villa, but also other objects discovered during the excavations, attesting to the early human presence, including stone axes dating to 3,600 BC, bronze objects from the second and third centuries and other finds from the Iron Age.

Portugal's Roman Villa da Corte reveals its secrets
The marble slab inscribed with the name ‘Yehiel’ in Hebrew
[Credit: Dennis Graen/FSU]

More intruiging is a marble panel, found in 2011, identified as a tombstone, dating from no later than 390 BC, inscribed with the name ‘Yehiel’ in Hebrew, and which is the oldest Jewish artefact discovered in the Iberian Peninsula to date.

The exhibition, entitled “Villa Romana da Corte: Dinâmica de ocupação e quotidiano de uma população rural”, was inaugurated on May 18, International Museum Day, and will remain at the Sala de Exposições do Museu Municipal de Arqueologia de Silves until January 10, 2019.

Source: Terra Ruiva [July 10, 2018]




Iron Age graves brought to light at Capodimonte, Naples

Excavations in the Buccacce area at Capodimonte, Naples, under the direction of the Superintendence have brought to light fifteen burials of which five are simple pit graves and ten are tufa sarcophagi from the 8th-7th century BC.

The excavations continued for two weeks and were completed on 6 July.

Iron Age graves brought to light at Capodimonte, Naples

Iron Age graves brought to light at Capodimonte, Naples

Iron Age graves brought to light at Capodimonte, Naples
Credit: Tuscia Web

Among the numerous grave goods retrieved are ceramic and bronze vases, pitchers with intertwining handles, about a hundred Bisenzio oil jars of various sizes, kantharoi and cups, as well as spears, javelins and bronze brooches.

Iron Age graves brought to light at Capodimonte, Naples
Credit: Tuscia Web

“All the material” says the mayor Mario Fanelli “is now kept in the town hall waiting to be studied and then eventually exhibited”.

Source: Tuscia Web [July 10, 2018]




Early Byzantine church with mosaic floor unearthed in ancient city of Stratonikeia

Researchers have unearthed what they believe to be a 1,500-year-old church along with a mosaic floor in the ancient city of Stratonikeia in southwestern Turkey’s Muğla province.

Early Byzantine church with mosaic floor unearthed in ancient city of Stratonikeia
AA Photo

Professor Bilal Söğüt of Pamukkale University, the head of the Stratonikeia excavations, told Anadolu Agency (AA) that archaeologists were finally able to excavate the church in its entirety and discovered a mosaic floor during the process.

The church, which has been dubbed as Erikli Church, is special both in terms of archaeology and architecture, Söğüt explained. “Erikli Church is one of the places to which people gave most donations during the Early Byzantine period,” he said, adding that the team found many relics such as crosses, lanterns and even containers from North Africa.

He said some parts of the church, especially the columns, were of high quality both in terms of construction and workmanship. “We will hopefully glimpse how this place looked originally after we are done restoring it,” he said.

The church was first used around the fourth century AD and was completely abandoned in the early seventh century, according to Söğüt.

He stated that every year the excavation team uncovers new information about the ancient city.

“Stratonikeia is a living ancient city. It is a unique settlement. There is no other ancient city where you can see structures belonging to the ancient times and the modern times that are all protected until the present day,” he said.

Source: Daily Sabah [July 11, 2018]




Bugs in Bones In the 1990s, archaeologists excavating the…

Bugs in Bones

In the 1990s, archaeologists excavating the remains of the Convent of Santa Isabel near Mexico City made a grisly discovery, uncovering the skeletons of more than 200 foetuses, newborns and babies dating from the 17th to the 19th century. We don’t know how most of them died, but researchers have now been able to tell that at least three of them were infected with Treponema pallidum bacteria. One strain of Treponema causes syphilis, which can be passed from mother to child, while another version causes a disfiguring childhood disease called yaws. These bones show tell-tale signs of infection, but it’s difficult to tell which of the two strains caused it. Researchers have now been able to read the genetic code of bacterial DNA extracted from the bones and show that two babies were infected with syphilis while one had yaws, providing new information about the spread of these infections through South America.

Written by Kat Arney

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Kilmichael Glassary Prehistoric Rock Art, Kilmartin Glen, Argyll…

Kilmichael Glassary Prehistoric Rock Art, Kilmartin Glen, Argyll 14.7.18.

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Шаровая молния город Тюмень

Случай во время грозового шторма в Тюмени 10 июля 2018.

Source: Ball lightning during a thunderstorm by SpaceTrack

Случайная запись неизвестного явления, во время грозы настраивались камеры для съёмки.

После просмотра на ПК обнаружилась короткая вспышка около одной секунды. Можно считать это шаровой молнией, продолжительность жизни шаровых молний не превышает 2 секунд, так же был слышен хлопок, явление возникло не более чем в 2 км от камеры.



2018 July 15 Rings Around the Ring Nebula Image Credit: Hubble,…

2018 July 15

Rings Around the Ring Nebula
Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition & Copyright: Robert Gendler

Explanation: There is much more to the familiar Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure – a collaborative effort combining data from three different large telescopes – explores the looping filaments of glowing gas extending much farther from the nebula’s central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra.

∞ Source: apod.nasa.gov/apod/ap180715.html


Could gravitational waves reveal how fast our universe is expanding?

Artist’s depiction of the last instances of a neutron star and black hole merger, as the neutron star is destroyed by the tidal pull of the black hole (at the center of the disk). Image: A. Tonita, L. Rezzolla, F. Pannarale

Signals from rare black hole-neutron star pairs could pinpoint rate at which universe is growing, researchers say.

Since it first exploded into existence 13.8 billion years ago, the universe has been expanding, dragging along with it hundreds of billions of galaxies and stars, much like raisins in a rapidly rising dough.

Astronomers have pointed telescopes to certain stars and other cosmic sources to measure their distance from Earth and how fast they are moving away from us — two parameters that are essential to estimating the Hubble constant, a unit of measurement that describes the rate at which the universe is expanding.

But to date, the most precise efforts have landed on very different values of the Hubble constant, offering no definitive resolution to exactly how fast the universe is growing. This information, scientists believe, could shed light on the universe’s origins, as well as its fate, and whether the cosmos will expand indefinitely or ultimately collapse.

Now scientists from MIT and Harvard University have proposed a more accurate and independent way to measure the Hubble constant, using gravitational waves emitted by a relatively rare system: a black hole-neutron star binary, a hugely energetic pairing of a spiraling black hole and a neutron star. As these objects circle in toward each other, they should produce space-shaking gravitational waves and a flash of light when they ultimately collide.

In a paper published today in Physical Review Letters, the researchers report that the flash of light would give scientists an estimate of the system’s velocity, or how fast it is moving away from the Earth. The emitted gravitational waves, if detected on Earth, should provide an independent and precise measurement of the system’s distance. Even though black hole-neutron star binaries are incredibly rare, the researchers calculate that detecting even a few should yield the most accurate value yet for the Hubble constant and the rate of the expanding universe.

“Black hole-neutron star binaries are very complicated systems, which we know very little about,” says Salvatore Vitale, assistant professor of physics at MIT and lead author of the paper. “If we detect one, the prize is that they can potentially give a dramatic contribution to our understanding of the universe.”

Vitale’s co-author is Hsin-Yu Chen of Harvard.

Competing constants

Two independent measurements  of the Hubble constant were made recently, one using NASA’s Hubble Space Telescope and another using the European Space Agency’s Planck satellite. The Hubble Space Telescope’s measurement is based on observations of a type of star known as a Cepheid variable, as well as on observations of supernovae. Both of these objects are considered “standard candles,” for their predictable pattern of brightness, which scientists can use to estimate the star’s distance and velocity.

The other type of estimate is based on observations of the fluctuations in the cosmic microwave background — the electromagnetic radiation that was left over in the immediate aftermath of the Big Bang, when the universe was still in its infancy. While the observations by both probes are extremely precise, their estimates of the Hubble constant disagree significantly.

“That’s where LIGO comes into the game,” Vitale says.

LIGO, or the Laser Interferometry Gravitational-Wave Observatory, detects gravitational waves — ripples in the Jell-O of space-time, produced by cataclysmic astrophysical phenomena.

“Gravitational waves provide a very direct and easy way of measuring the distances of their sources,” Vitale says. “What we detect with LIGO is a direct imprint of the distance to the source, without any extra analysis.”

In 2017, scientists got their first chance at estimating the Hubble constant from a gravitational-wave source, when LIGO and its Italian counterpart Virgo detected a pair of colliding neutron stars for the first time. The collision released a huge amount of gravitational waves, which researchers measured to determine the distance of the system from Earth. The merger also released a flash of light, which astronomers focused on with ground and space telescopes to determine the system’s velocity.

With both measurements, scientists calculated a new value for the Hubble constant. However, the estimate came with a relatively large uncertainty of 14 percent, much more uncertain than the values calculated using the Hubble Space Telescope and the Planck satellite.

Vitale says much of the uncertainty stems from the fact that it can be challenging to interpret a neutron star binary’s distance from Earth using the gravitational waves that this particular system gives off.   

“We measure distance by looking at how ‘loud’ the gravitational wave is, meaning how clear it is in our data,” Vitale says. “If it’s very clear, you can see how loud it is, and that gives the distance. But that’s only partially true for neutron star binaries.”

That’s because these systems, which create a whirling disc of energy as two neutron stars spiral in toward each other, emit gravitational waves in an uneven fashion. The majority of gravitational waves shoot straight out from the center of the disc, while a much smaller fraction escapes out the edges. If scientists detect a “loud” gravitational wave signal, it could indicate one of two scenarios: the detected waves stemmed from the edge of a system that is very close to Earth, or the waves emanated from the center of a much further system.

“With neutron star binaries, it’s very hard to distinguish between these two situations,” Vitale says.

A new wave

In 2014, before LIGO made the first detection of gravitational waves, Vitale and his colleagues observed that a binary system composed of a black hole and a neutron star could give a more accurate distance measurement, compared with neutron star binaries. The team was investigating how accurately one could measure a black hole’s spin, given that the objects are known to spin on their axes, similarly to Earth but much more quickly.

The researchers simulated a variety of systems with black holes, including black hole-neutron star binaries and neutron star binaries. As a byproduct of this effort, the team noticed that they were able to more accurately determine the distance of black hole-neutron star binaries, compared to neutron star binaries. Vitale says this is due to the spin of the black hole around the neutron star, which can help scientists better pinpoint from where in the system the gravitational waves are emanating.

“Because of this better distance measurement, I thought that black hole-neutron star binaries could be a competitive probe for measuring the Hubble constant,” Vitale says. “Since then, a lot has happened with LIGO and the discovery of gravitational waves, and all this was put on the back burner.”

Vitale recently circled back to his original observation, and in this new paper, he set out to answer a theoretical question:

“Is the fact that every black hole-neutron star binary will give me a better distance going to compensate for the fact that potentially, there are far fewer of them in the universe than neutron star binaries?” Vitale says.

To answer this question, the team ran simulations to predict the occurrence of both types of binary systems in the universe, as well as the accuracy of their distance measurements. From their calculations, they concluded that, even if neutron binary systems outnumbered black hole-neutron star systems by 50-1, the latter would yield a Hubble constant similar in accuracy to the former.

More optimistically, if black hole-neutron star binaries were slightly more common, but still rarer than neutron star binaries, the former would produce a Hubble constant that is four times as accurate.

“So far, people have focused on binary neutron stars as a way of measuring the Hubble constant with gravitational waves,” Vitale says. “We’ve shown there is another type of gravitational wave source which so far has not been exploited as much: black holes and neutron stars spiraling together,” Vitale says. “LIGO will start taking data again in January 2019, and it will be much more sensitive, meaning we’ll be able to see objects farther away. So LIGO should see at least one black hole-neutron star binary, and as many as 25, which will help resolve the existing tension in the measurement of the Hubble constant, hopefully in the next few years.”

This research was supported, in part, by the National Science Foundation and the LIGO Laboratory.

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Every person has a unique brain anatomy

Like with fingerprints, no two people have the same brain anatomy, a study by researchers of the University of Zurich has shown. This uniqueness is the result of a combination of genetic factors and individual life experiences.

Every person has a unique brain anatomy
Three brain scans (from the front, side and above) of two different brains (pictured on the left and on the right)
belonging to twins. The furrows and ridges are different in each person [Credit: Lutz Jaencke, UZH]

The fingerprint is unique in every individual: As no two fingerprints are the same, they have become the go-to method of identity verification for police, immigration authorities and smartphone producers alike. But what about the central switchboard inside our heads? Is it possible to find out who a brain belongs to from certain anatomical features? This is the question posed by the group working with Lutz Jäncke, UZH professor of neuropsychology. In earlier studies, Jäncke had already been able to demonstrate that individual experiences and life circumstances influence the anatomy of the brain.

Experiences make their mark on the brain

Professional musicians, golfers or chess players, for example, have particular characteristics in the regions of the brain which they use the most for their skilled activity. However, events of shorter duration can also leave behind traces in the brain: If, for example, the right arm is kept still for two weeks, the thickness of the brain’s cortex in the areas responsible for controlling the immobilized arm is reduced. “We suspected that those experiences having an effect on the brain interact with the genetic make-up so that over the course of years every person develops a completely individual brain anatomy,” explains Jäncke.

Magnetic resonance imaging provides basis for calculations

To investigate their hypothesis, Jäncke and his research team examined the brains of nearly 200 healthy older people using magnetic resonance imaging three times over a period of two years. Over 450 brain anatomical features were assessed, including very general ones such as total volume of the brain, thickness of the cortex, and volumes of grey and white matter. For each of the 191 people, the researchers were able to identify an individual combination of specific brain anatomical characteristics, whereby the identification accuracy, even for the very general brain anatomical characteristics, was over 90 percent.

Combination of circumstances and genetics

“With our study we were able to confirm that the structure of people’s brains is very individual,” says Lutz Jäncke on the findings. “The combination of genetic and non-genetic influences clearly affects not only the functioning of the brain, but also its anatomy.” The replacement of fingerprint sensors with MRI scans in the future is unlikely, however. MRIs are too expensive and time-consuming in comparison to the proven and simple method of taking fingerprints.

Progress in neuroscience

An important aspect of the study’s findings for Jäncke is that they reflect the great developments made in the field in recent years: “Just 30 years ago we thought that the human brain had few or no individual characteristics. Personal identification through brain anatomical characteristics was unimaginable.” In the meantime magnetic resonance imaging has got much better, as has the software used to evaluate digitalized brain scans – Jäncke says it is thanks to this progress that we now know better.

The findings are published in Scientific Reports.

Source: University of Zurich [July 10, 2018]





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