вторник, 8 января 2019 г.

Milky Way heading for catastrophic collision

New research led by astrophysicists at Durham University, UK, predicts that the Large Magellanic Cloud (LMC) could hit the Milky Way in two billion years’ time.

Milky Way heading for catastrophic collision
The Whirlpool Galaxy (M51a) and companion galaxy (M51b). This Hubble Space Telescope image represents
a merger between two galaxies similar in mass to the Milky Way and the Large Magellanic Cloud
[Credit: NASA, ESA, S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA)]

The collision could occur much earlier than the predicted impact between the Milky Way and another neighbouring galaxy, Andromeda, which scientists say will hit our galaxy in eight billion years.

The catastrophic coming together with the Large Magellanic Cloud could wake up our galaxy’s dormant black hole, which would begin devouring surrounding gas and increase in size by up to ten times.

As it feeds, the now-active black hole would throw out high-energy radiation and while these cosmic fireworks are unlikely to affect life on Earth, the scientists say there is a small chance that the initial collision could send our Solar System hurtling into space.

Galaxies like our own Milky Way are surrounded by a group of smaller satellite galaxies that orbit around them, in a similar way to how bees move around a hive.

Typically, these satellite galaxies have a quiet life and orbit around their hosts for many billions of years. However, from time to time, they sink to the centre, collide and are devoured by their host galaxy.

The Large Magellanic Cloud is the brightest satellite galaxy of the Milky Way and only entered our neighbourhood about 1.5 billion years ago. It sits about 163,000 light years from the Milky Way.

Until recently astronomers thought that it would either orbit the Milky Way for many billions of years, or, since it moves so fast, escape from our galaxy’s gravitational pull.

Milky Way heading for catastrophic collision
This vibrant image from NASA’s Spitzer Space Telescope shows the Large Magellanic Cloud,
a satellite galaxy to our own Milky Way galaxy [Credit: NASA/JPL-Caltech/STScI]

However, recent measurements indicate that the Large Magellanic Cloud has nearly twice as much dark matter than previously thought. The researchers say that since it has a larger than expected mass, the Large Magellanic Cloud is rapidly losing energy and is doomed to collide with our galaxy.

The research team, led by scientists at Durham University’s Institute for Computational Cosmology working with the University of Helsinki, in Finland, used the EAGLE galaxy formation supercomputer simulation to predict the collision.

Lead author Dr. Marius Cautun, a postdoctoral fellow in Durham University’s Institute for Computational Cosmology, said: “While two billion years is an extremely long time compared to a human lifetime, it is a very short time on cosmic timescales.

“The destruction of the Large Magellanic Cloud, as it is devoured by the Milky Way, will wreak havoc with our galaxy, waking up the black hole that lives at its centre and turning our galaxy into an ‘active galactic nucleus’ or quasar.

“This phenomenon will generate powerful jets of high energy radiation emanating from just outside the black hole. While this will not affect our Solar System, there is a small chance that we might not escape unscathed from the collision between the two galaxies which could knock us out of the Milky Way and into interstellar space.”

The collision between the Large Magellanic Cloud and the Milky Way could be spectacular, the researchers say.

Simulation of the evolution of a galaxy similar to our own. The bright regions correspond to stars. The video shows the 

approach of a secondary smaller galaxy, a so-called satellite galaxy, that shortly afterwards gets devoured by the central 

galaxy. As the smaller galaxy gets destroyed, stars get ejected from the central region. Although the chances are small, our Sun

 could be one of those stars condemned to a long and lonely wander through the cold and dark intergalactic space. The movie

 shows a similar evolution to what researchers predict for the collision between our galaxy and the Large Magellanic Cloud 

Cosmology, Durham University, UK, the Heidelberg Institute for Theoretical Studies, Germany, 

and the Max Planck Institute for Astrophysics, Germany]

Co-author Professor Carlos Frenk, Director of the Institute for Computational Cosmology, Durham University, said: “Beautiful as it is, our Universe is constantly evolving, often through violent events like the forthcoming collision with the Large Magellanic Cloud.

“Barring any disasters, like a major disturbance to the Solar System, our descendants, if any, are in for a treat: a spectacular display of cosmic fireworks as the newly awakened supermassive black hole at the centre of our galaxy reacts by emitting jets of extremely bright energetic radiation.”

According to the researchers, the merger of the two galaxies could be long overdue in cosmic terms.

Dr. Alis Deason, of Durham University’s Institute for Computational Cosmology, said: “We think that up to now our galaxy has had only a few mergers with very low mass galaxies.

“This represents very slim pickings when compared to nearby galaxies of the same size as the Milky Way. For example, our nearest neighbour, the Andromeda galaxy, devoured galaxies weighing nearly 30 times more than those consumed by the Milky Way.

“Therefore, the collision with the Large Magellanic Cloud is long overdue and it is needed to make our galaxy typical.”

The findings are published in the journal Monthly Notices of the Royal Astronomical Society.

Source: Durham University [January 04, 2019]



Climate warming experiment finds unexpected results

Tropical forests store about a third of Earth’s carbon and about two-thirds of its above-ground biomass. Most climate change models predict that as the world warms, all of that biomass will decompose more quickly, which would send a lot more carbon dioxide into the atmosphere. But new research presented at the American Geophysical Union’s 2018 Fall Meeting contradicts that theory.

Climate warming experiment finds unexpected results
Dried leaf samples are bagged and numbered before being returned to study sites in Puerto Rico’s
El Yunque National Forest. Heaters warmed experimental plots to four degrees higher than
the ambient temperature of the tropical forest [Credit: Stephanie Roe]

Stephanie Roe, an ecology Ph.D. student at the University of Virginia, measured the rate of decomposition in artificially warmed plots of forest in Puerto Rico. She found biomass in the warmed plots broke down more slowly than samples from a control site that wasn’t warmed.

Her results indicate that as the climate warms, forest litter could pile up on the ground, instead of breaking down into the soil. Less decomposition means less carbon dioxide released back into the atmosphere. But it also means less carbon taken up by the soil, where it’s needed to fuel microbial processes that help plants grow.

“These results could have significant implications on the carbon cycle in a warmer future,” Roe said.

Roe said there are few empirical studies of how tropical forests will respond to climate change. She set out to address this gap in June of 2017, when she and her research team travelled to El Yunque National Forest in Puerto Rico. They landed at a site called TRACE—the Tropical Responses to Altered Climate Experiment.

TRACE is the first-ever long-term warming experiment conducted in a tropical forest. It was established by the US Forest Service in 2016 for research like Roe’s. The site consists of three hexagonal plots of land enclosed by a ring of infrared heaters raised four meters above the ground, and three more plots enclosed by fake heaters that are used as the “control” forest.

Roe collected leaves from the plots, dried them out in the lab, and then returned them to the plots randomly. In addition to the native plants, she also included black and green tea, and popsicle sticks to represent woody biomass, to see how different materials would respond to the warming.

The heaters were programmed to continuously heat the plots to four degrees higher than the ambient temperature of the forest. The experiment was supposed to run for a full year, but at the beginning of October, Hurricane Maria swept across the island, destroying the TRACE sites.

Roe was back in Virginia when the storm struck. She had collected samples from the first few months of the experiment, and they were already showing signs of significant decomposition, so she decided to go ahead with the analysis based on what she had. And the results were not what she thought they would be.

“We would expect that microbes tend to work faster, like their metabolisms increase, with warmer temperatures,” Roe said. “So we would expect to see an increase of activity of microbes and other decomposers to decompose the litter.”

But instead of seeing faster rates of decomposition, Roe observed the warming produced a drying effect in the plots, which slowed decomposition. “What we found is actually it went the other way because moisture was impacted so much,” Roe said. Moisture in the litter from the treatment sites was reduced by an average of 38 percent.

Roe pointed out that the increase in frequency and severity of storms in the region could amplify this effect. Hurricane Maria reduced significant portions of the tree canopy in El Yunque, allowing a lot more sunlight to reach the forest floor that can dry up the litter.

The results Roe shared are preliminary and not yet published. Her next project is to do further analysis of the nutrients in the litter and of the microbial communities to see if there are other factors that could explain the unexpected slowdown in decomposition.

Author: Emily Pontecorvo | Source: American Geophysical Union [January 04, 2019]



The long memory of the Pacific Ocean

The ocean has a long memory. When the water in today’s deep Pacific Ocean last saw sunlight, Charlemagne was the Holy Roman Emperor, the Song Dynasty ruled China and Oxford University had just held its very first class. During that time, between the 9th and 12th centuries, the earth’s climate was generally warmer before the cold of the Little Ice Age settled in around the 16th century. Now ocean surface temperatures are back on the rise but the question is, do the deepest parts of the ocean know that?

The long memory of the Pacific Ocean
Cold waters that sank in polar regions hundreds of years ago during the Little Ice Age are still impacting deep Pacific
Ocean temperature trends. While the deep Pacific temperature trends are small, they represent a large amount
of energy in the Earth system [Credit: Larry Madin, Woods Hole Oceanographic Institution]

Researchers from the Woods Hole Oceanographic Institution (WHOI) and Harvard University have found that the deep Pacific Ocean lags a few centuries behind in terms of temperature and is still adjusting to the entry into the Little Ice Age. Whereas most of the ocean is responding to modern warming, the deep Pacific may be cooling.

“These waters are so old and haven’t been near the surface in so long, they still ‘remember’ what was going on hundreds of years ago when Europe experienced some of its coldest winters in history,” said Jake Gebbie, a physical oceanographer at WHOI and lead author of the study published in the journal Science.

“Climate varies across all timescales,” adds Peter Huybers, Professor of Earth and Planetary Sciences at Harvard University and co-author of the paper. “Some regional warming and cooling patterns, like the Little Ice Age and the Medieval Warm Period, are well known. Our goal was to develop a model of how the interior properties of the ocean respond to changes in surface climate.”

What that model showed was surprising.

“If the surface ocean was generally cooling for the better part of the last millennium, those parts of the ocean most isolated from modern warming may still be cooling,” said Gebbie.

The model is, of course, a simplification of the actual ocean. To test the prediction, Gebbie and Huybers compared the cooling trend found in the model to ocean temperature measurements taken by scientists aboard the HMS Challenger in the 1870s and modern observations from the World Ocean Circulation Experiment of the 1990s.

The long memory of the Pacific Ocean
The HMS Challenger, a three-masted wooden sailing ship originally designed as a British warship, was used for the first
modern scientific expedition to explore the world’s ocean and seafloor. Gebbie and Huybers compared the cooling trend
found in the model to ocean temperature measurements taken by scientists aboard the HMS Challenger in the 1870s
 and modern observations from the World Ocean Circulation Experiment of the 1990s [Credit: Painting of the
HMS Challenger by William Frederick Mitchell originally published for the Royal Navy]

The HMS Challenger, a three-masted wooden sailing ship originally designed as a British warship, was used for the first modern scientific expedition to explore the world’s ocean and seafloor. During the expedition from 1872 to 1876, thermometers were lowered into the ocean depths and more than 5,000 temperature measurements were logged.

“We screened this historical data for outliers and considered a variety of corrections associated with pressure effects on the thermometer and stretching of the hemp rope used for lowering thermometers,” said Huybers.

The researchers then compared the HMS Challenger data to the modern observations and found warming in most parts of the global ocean, as would be expected due to the warming planet over the 20th Century, but cooling in the deep Pacific at a depth of around two kilometers.

“The close correspondence between the predictions and observed trends gave us confidence that this is a real phenomenon,” said Gebbie.

These findings imply that variations in surface climate that predate the onset of modern warming still influence how much the climate is heating up today. Previous estimates of how much heat the Earth had absorbed during the last century assumed an ocean that started out in equilibrium at the beginning of the Industrial Revolution. But Gebbie and Huybers estimate that the deep Pacific cooling trend leads to a downward revision of heat absorbed over the 20th century by about 30 percent.

“Part of the heat needed to bring the ocean into equilibrium with an atmosphere having more greenhouse gases was apparently already present in the deep Pacific,” said Huybers. “These findings increase the impetus for understanding the causes of the Medieval Warm Period and Little Ice Age as a way for better understanding modern warming trends.”

Source: Woods Hole Oceanographic Institution [January 04, 2019]



Strength in weakness: Fragile DNA regions key to vertebrate evolution

Regions of DNA susceptible to deletion during replication may have allowed vertebrates to successfully adapt to rapidly changing environmental conditions during evolution, according to a study by researchers at the Stanford University School of Medicine.

Strength in weakness: Fragile DNA regions key to vertebrate evolution
David Kingsley and his lab study the threespine stickeback, tiny fish that evolved as they adapted
 to two different environments: fresh water and the ocean [Credit: Kathy Xie]

The research suggests that some critical evolutionary changes are likely to have occurred in leaps and bounds through the abrupt loss of stretches of DNA, rather than through the slow accumulation and additive effects of many small mutations.

The researchers, who studied a tiny fish called the threespine stickleback, found that such “fragile” DNA regions create genetic hot spots that mutate much more rapidly, and dramatically, than neighboring sequences. The resulting changes can help an organism vault far ahead of its peers in the evolutionary arms race.

Although similar findings have been described in bacteria, this is one of the first studies to show that the same process has occurred in vertebrates to create dramatic changes in body structure. It also addresses a long-standing mystery in evolutionary biology.

“There is a lot of evidence that the same genes across different populations or species are often responsible for similar evolutionary changes,” said David Kingsley, Ph.D., professor of developmental biology. “What hasn’t been clear is why this is happening. This study describes at a biochemical level, down to the atoms and sequences in DNA, how a particular type of mutation can arise repeatedly, which then contributes to a complex skeletal trait evolving over and over again in wild fish species. It’s a great example of how DNA fragility can sometimes contribute to favorable traits rather than diseases in natural populations, and it may give us important insights into the process of human evolution.”

Kingsley, a Howard Hughes Medical Institute investigator, is the senior author of the study, which was published in the journal Science. Graduate student Kathleen Xie is the lead author of the work.

Large changes, large effects

Many mutations involve a change in just a single nucleotide, or letter, of DNA. Few of these “point” mutations will confer an evolutionary advantage on their own. Instead, significant change often requires the gradual accumulation of several such mutations. In contrast, sudden, large changes in the genome can have large effects—changing body structure through skeletal modifications or affecting metabolism or brain function, for example. Often, these changes are deleterious, decreasing the chances of an animal’s survival. Occasionally, however, the changes are advantageous.

When the last Ice Age ended, about 10,000 years ago, pockets of migratory ocean threespine sticklebacks colonized newly formed lakes and streams in coastal regions, and then evolved independently in response to their new local environments. As a result, many of these populations show significant differences in body structure. Marine sticklebacks, for example, have a hind fin with a large spine projecting down from their pelvic structure. In contrast, dozens of freshwater populations have lost that hind fin; its absence likely reduces their need for calcium and chances of being nabbed and eaten by hungry insects.

Previous studies in the Kingsley laboratory have identified the loss of a specific DNA regulatory region, called the Pel enhancer, as the repeated cause of the missing hind fins in many populations of the freshwater fish. The Pel enhancer drives the expression of a protein necessary to trigger hind fin development. In this study, Xie used marine stickleback DNA to investigate the Pel region that is missing in its freshwater brethren to learn why that region was particularly susceptible to loss.

Xie found that the DNA sequence of the Pel region is unusual in several ways. Unlike surrounding regions, which exhibit the normal, more-stable helical twist associated with most DNA, the Pel enhancer region that was lost formed an alternate DNA structure predicted to be highly flexible and likely to be unstable during DNA replication. The sequence also contains long strings of repeated pairs of nucleotides, like a kind of genetic stutter. Previous studies in bacteria, mice and humans have indicated that these repeats are often associated with deletions of stretches of DNA.

More frequent chromosome breaking

When Xie tested the stability of the missing Pel region by inserting it into artificial yeast chromosomes, she found that the chromosome broke about 25 to 50 times more frequently than typical DNA sequences. When Xie and her collaborators then tested similar DNA sequences in mammalian cells, they observed that the key dinucleotide repeat sequence often led to the deletion of sections of DNA more than 100 nucleotides long.

The increase in the rate of chromosome breakage observed by Xie, coupled with the likelihood that this damage causes deletions of entire sections of DNA, may have been a key factor in allowing the prominent hind fin skeletal trait to emerge over and over again in many different young stickleback populations. Elevated mutation rates may play a similar role when advantageous traits arise in other organisms, the scientists believe.

“Many vertebrates, including early humans, are dealing with a small population size and relatively long generation times,” said Kingsley, who is the Rudy J. and Daphne Donohue Munzer Professor in the School of Medicine. “There aren’t that many generations available in which to evolve new, potentially advantageous traits. Under these conditions, it may be particularly important for mutations to occur at elevated rates, and to have sweeping effects.”

When the researchers investigated known instances of adaptive changes in humans, they found that about half were due to mutations that also arise at elevated rates compared with more typical DNA letter changes.

“What we’re learning is that ‘arrival of the fittest,’ or the relative speed with which a potentially favorable mutation arises, can sometimes be as important as ‘survival of the fittest,'” Kingsley said. “The mutation process itself has an important effect on the outcome, and the arrival of the mutation interacts with its effect on the fitness of the organism to bring about major changes in vertebrate evolution.”

Author: Krista Conger | Source: Stanford University Medical Center [January 04, 2019]



Mammoth DNA found in Cambodia market items

Scientists tackling the illegal trade in elephant ivory got more than they bargained for when they found woolly mammoth DNA in trinkets on sale in Cambodia, they revealed Friday.

Mammoth DNA found in Cambodia market items
The frame specimen of a mammoth is displayed at an exhibition in Yokohama, suburban Tokyo on July 12, 2013;
the giant mammals have been extinct for around 10,000 years and are not covered by
international agreements on endangered species [Credit: Kazuhiro Nogi]

“It was a surprise for us to find trinkets made from woolly mammoth ivory in circulation, especially so early into our testing and in a tropical country like Cambodia,” said Alex Ball, manager at the WildGenes laboratory, a wildlife conservation charity based at Edinburgh Zoo.

“It is very hard to say what the implications of this finding are for existing elephant populations, however we plan to continue our research and will use genetics to work out where it has come from.”

The giant mammals have been extinct for around 10,000 years and are not covered by international agreements on endangered species.

WildGenes has been using genetic data to tackle wildlife crime by determining the origin of ivory finding its way to the marketplace.

“It is estimated that globally over 30,000 elephants are killed every year for their ivory and it appears there are increasing amounts of ivory for sale within Cambodia,” said Ball.

“Understanding where the ivory is coming from is vital for enforcement agencies looking to block illegal trade routes.”

Britain last year banned sales of all ivory except for the rarest and most important antiques.

Source: AFP [January 04, 2019]



Ancient urban villa with shrine for ancestor worship discovered in Egypt

Excavation work led by the University of Chicago’s Oriental Institute team has unearthed a large urban villa dating back to the early New Kingdom, about 1500-1450 B.C.E. The findings at the site of Tell Edfu in southern Egypt include a large hall containing a rare and well-preserved example of a domestic shrine dedicated to family ancestors.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
View (from the east) of the main columned hall of the early 18th Dynasty urban villa discovered at Tell Edfu
[Credit: GM – Tell Edfu Project 2018]

“It has been more than 80 years since such a shrine for the ancestors was discovered in Egypt, and the ones we did have were rarely within an undisturbed context,” said Nadine Moeller, associate professor of Egyptian archaeology at UChicago, who leads the Tell Edfu Project excavation with Oriental Institute research associate Gregory Marouard.
Located about 400 miles south of Cairo in the Nile Valley, the ancient city of Tell Edfu was a provincial capital occupied for nearly 3,000 years. The archaeological fieldwork has excavated settlement remains and monuments from Egypt’s Old Kingdom (ca. 2400 B.C.E.) all the way to the Ptolemaic period (332-30 B.C.E). The project is currently part of the work of the Oriental Institute, a leading center for the study of ancient Near Eastern civilizations founded in 1919.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
A view of the column area under excavation (left) and the sandstone column inscribed with the name of the high priest
of the temple of Horus, Amenmose (right) [Credit: GM and HMD – Tell Edfu Project 2018]

The latest discovery at the site of Tell Edfu is one of the earliest examples of an ancestral shrine from the New Kingdom, and the first archaeological example discovered in many decades, Moeller and Marouard said.

The last excavation, completed in December 2018, has focused on a large urban villa of about 440 square yards, which dates from the beginning of the 18th dynasty of Egypt. The building has several rooms with columns, the largest, a six-columned hall measuring about 33 feet by 26 feet, contains a well-preserved domestic sanctuary dedicated to the cult of the family ancestors of the inhabitants.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
Bust of a female ancestor found on the floor of the domestic sanctuary. She wears a long tripartite wig
and a broad necklace called a wesekh collar [Credit: GM and HMD – Tell Edfu Project 2018]

The shrine was located in a corner of the main room, and traces indicate it was surrounded by a wooden structure. It includes a small fireplace and offering table, two small pedestals in mudbrick, several complete or fragmented stelae (upright inscribed slabs of stone or wood), a rare example of a bust of a female ancestor, and a statuette of a seated scribe.
The limestone bust shows a woman wearing a long tripartite wig and a broad necklace called a wesekh collar. Traces of paint indicate that this small 8-inch bust once had been painted.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
Female ancestor bust of limestone. She wears a long tripartite wig and a broad necklace called a wesekh collar
[Credit: GM and HMD – Tell Edfu Project 2018]

The statuette of the scribe, carved out of hard black diorite, shows a man seated on a chair, wearing a shoulder-length wig and a long tight-fitting kilt clutching a papyrus roll in front of his chest with his left hand. Inscriptions indicate he was a high-level administrator at Edfu named Juf.
Nearby was also what Moeller described as a “small but significant” limestone stela, which shows a man and women standing next to each other in raised relief in the center. Though the hieroglyphic text surrounding the couple mentions the common offering formula and includes the names and titles of the two figures, their faces and names show signs of deliberate damage inflicted in ancient times, making it difficult to read their names.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
Statuette of a scribe, made of black diorite, found on the floor of the domestic sanctuary. Inscriptions indicate
he was a high-level administrator at Edfu named Juf [Credit: GM and HMD – Tell Edfu Project 2018]

“Currently our best knowledge about such cultic installations within a domestic house comes from the famous workmen village of Deir el-Medineh, near Luxor, dating to the much later Ramesside period. So far, our example from Tell Edfu is one of the oldest known for the New Kingdom period,” Moeller said.

“We are thrilled to find such a complete set of artifacts within their original archaeological context. This should help us answer a lot of questions about the various cultic activities that were carried out at this shrine, in addition to reconstructing the identities of the former owners who lived in this villa.”

Ancient urban villa with shrine for ancestor worship discovered in Egypt
Statuette of the seated scribe of the province of Edfu [Credit: GM and HMD – Tell Edfu Project 2018]

While excavating the later occupation levels above this villa, researchers also found a large sandstone column mentioning a high priest of the temple of Horus in Edfu called Amenmose, which dates to this time period but was reused in a house many centuries later.
The new findings reinforce the presence of an important high-ranking elite in this specific part of the ancient city of Edfu during the beginning of the 18th Dynasty, a period of political consolidation in Upper Egypt by the Theban kings Ahmose, Amenhotep I and Thutmose I, Moeller said.

Ancient urban villa with shrine for ancestor worship discovered in Egypt
Limestone stela showing a man and woman standing next to each other. Their faces and names show
signs of deliberate damage inflicted in ancient times, making it difficult to read their names
[Credit: GM and HMD – Tell Edfu Project 2018]

The Tell Edfu excavation, which began in 2001, has served as training for University of Chicago students for many years, Moeller said. This particular excavation included fieldwork by graduate students Emilie Sarrazin, Raghda el-Bahaedi, Sasha Rohret, Rebecca Wang and Maja Sunleaf.

Author: Louise Lerner | Source: University of Chicago [January 05, 2019]



Ancient petroglyphs suggests that a meteor has been observed in ancient times in Morocco

The pre-history of Morocco goes back thousands of years, as is evidenced by the many rock art engravings or petroglyphs in many areas. Three petroglyphs found near Ida Ou Kazzou could suggest that ancient Moroccans observed meteorite falls.

The new discovery was conducted by Moroccan researcher and IMO member Abderrahmane Ibhi and by Fouad Khiri, Lahcen Ouknine, Abdelkhalek Lemjidi, and El Mahfoud Asmahri. Moroccan researchers compared the engravings to other petroglyphs discovered previously in the region and also gathered testimonies from eyewitnesses of the fall of the Tissint meteorite in 2011, to reach the conclusion that the petroglyphs date back to ancient time, albeit not providing an idea on how old the engravings are.

The 3 petroglyphs found in the Ida Ou Kazzo area – Credits: Abderrahmane Ibhi

The first petroglyphs (called Ida1 by the Moroccan research team) offers a scene of two people seemingly distraught by the fall of a meteor. Identically on the 2nd one (Ida2), Ibhi and his team identified a scene that includes a fleeing anthropomorphic and what it looks like a huge fireball.

Petroglyph Ida1 engraving details – Original Photo Credits: Abderrahmane Ibhi – Illustration: AMS

On the third petroglyph (Ida3), the engraved scene includes an anthropomorphic, two cattle of different sizes, what it looks like a meteor and a figurative representation of the Sun with concentric circles in the center.

Ibhi and his team noted that the typology of these objects is very similar to the meteor engraving of Toca do Cosmos (Bahia, Brazil) and that of the rock painting in the Fouriesburg district (South Africa). Both artifacts are suspected to depict meteorite falls.

Figures from Toca do Cosmos (Brazil). On the center, the possible depiction of a comet. On the right, detail of the Comet Atlas from Mawangdui. Credits: Claudia Cunha; drawing, adapted from Xi, 1984

Fouriesburg rock painting described in “Comets, Meteors and Trance, Were these conceptually associated in Southern African pre-history?” by J.F. Thackeray (Monthly Notes of the Astron. Soc. Southern Africa, Vol. 47, p. 49 – 1988)

Ibhi and his team came to the conclusion that “these sculptures are those of a meteor, the three petroglyphs seem to represent the impact of a great meteorite that has frightened the inhabitants and that the artist has certainly experienced this astronomical event spectacular enough to be recorded on the rock“. Note that as suggest by J.F. Thackeray (Transvaal Museum, Pretoria) in 1988, comets and meteors have been conceptually associated with trance among at least some population groups in Southern Africa. The depiction of a stripe-like object (comet or meteor) in some prehistoric paintings and engravings, juxtaposed with human figures could reflect conceptual associations with trance experience rather than a specific astronomical event. Too bad prehistoric people didn’t have access to your online fireball report!

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2,800-year-old Aramaic incantation describes ‘Devourer’ that brings...

A 2,800-year-old incantation, written in Aramaic, describes the capture of a creature called the “devourer” said to be able to produce “fire.”

2,800-year-old Aramaic incantation describes 'Devourer' that brings 'fire' to victims
The ancient incantation had illustrations of animals such as scorpions on the front and back
[Credit: Roberto Ceccacci/Chicago-Tübingen Expedition to Zincirli]

Discovered in August 2017 within a small building, possibly a shrine, at the site of Zincirli (called “Sam’al” in ancient times), in Turkey, the incantation is inscribed on a stone cosmetic container. Written by a man who practiced magic who is called “Rahim son of Shadadan,” the incantation “describes the seizure of a threatening creature [called] the ‘devourer,'” wrote Madadh Richey and Dennis Pardee in the abstract of a presentation they gave recently at the Society of Biblical Literature annual meeting. That event took place in Denver between Nov 17 and 21.

The blood of the devourer was used to treat someone who appears to have been suffering from the “fire” of the devourer, said Richey, a doctoral student in the Department of Near Eastern Languages and Civilizations at the University of Chicago. It’s not clear whether the blood was given to the afflicted person in a potion that could be swallowed or whether it was smeared onto their body, Richey told Live Science.

“Accompanying the text are illustrations of various creatures, including what appears to be a centipede, a scorpion and a fish,” wrote Richey and Pardee, who is the Henry Crown professor of Hebrew studies at the University of Chicago, in the abstract. The illustrations are found on both sides of the cosmetic container.

The vessel would have originally stored makeup, and it appears to have been reused for the purpose of writing this incantation, said Virginia Herrmann, who is co-director of the Chicago-Tübingen Expedition to Zincirli, the team that uncovered the incantation.

What is the “devourer?”

The illustrations suggest that the “devourer” may actually be a scorpion or centipede; as such, the “fire” may refer to the pain of the creatures’ sting, Richey told Live Science.

2,800-year-old Aramaic incantation describes 'Devourer' that brings 'fire' to victims
The front of the incantation (part of which is shown here) included an illustration of a scorpion, a centipede
and Aramaic writing [Credit: Roberto Ceccacci/Chicago-Tübingen Expedition to Zincirli]

In fact, scorpions pose a hazard to archaeologists working at the site. “We always have to check our shoes and bags for scorpions on the excavation, even though most of the local scorpions do not have a very dangerous venom,” said Herrmann, noting that shortly after the incantation was removed from the site, “one of our local workers was stung by a scorpion that had crawled onto his backpack that was sitting on the ground,” and the archaeological team rushed to apply first aid.

Long life

Analysis of the incantation’s writing indicates that it was inscribed sometime between 850 B.C. and 800 B.C., said Richey, adding that this makes the inscription the oldest Aramaic incantation ever found. However, the small building where the incantation was found appears to date to more than a century later, to the late eighth or seventh century B.C., Herrmann told Live Science. This suggests that the incantation was considered important enough that it was kept long after Rahim would have inscribed it, Herrmann said.

The incantation “had a significance that long outlived its original owner,” Herrmann said. It was not the only artifact found in the small building that was kept long after it was created, she said, noting that a “statuette base of a crouching lion made of polished black stone with red inlaid eyes” was also discovered there. That lion figure appears to have been made in the 10th or ninth century B.C. The statuette base may have “once supported a metal figurine of a striding deity,” Herrmann added.

Sam’al, where the building is located, was the capital of a small Aramaean kingdom that flourished between roughly 900 B.C. and 720 B.C., said Herrmann, noting that the city was seized by the Assyrians around 720 B.C.

Author: Owen Jarus | Source: Live Science [December 26, 2018]



8,000-year-old ‘gum’ holds surprises about ancient toolmakers in Scandinavia

Gum won’t really sit in your stomach for years, but it can preserve human DNA for millennia. Researchers have uncovered genetic material encased within 8000-year-old tarlike wads known as birch bark pitch, which Scandinavian hunter-gatherers chewed to make a glue for weapons and tools. Among other things, the DNA suggests these toolmakers were both male and female, and some may have been as young as 5 years old.

8,000-year-old ‘gum’ holds surprises about ancient toolmakers in Scandinavia
Tarlike birch bark pitch from Sweden preserved both clear tooth impressions and DNA for thousands of years
[Credit: N. Kashuba et al. 2018]

“It’s exciting … that you could get DNA from something people chewed thousands of years ago,” says Lisa Matisoo-Smith, a molecular anthropologist at the University of Otago in Dunedin, New Zealand. “I think there are lots of ways people will take this going forward.”

In the late 1980s, a team of Swedish archaeologists excavated a pit within an archaeological site called Huseby Klev in western Sweden. Here, they discovered more than 100 coal black, thumbprint-size lumps riddled with distinct toothmarks. Chemical analysis revealed these were pieces of pitch, an early adhesive derived from plant resin. Researchers already knew ancient toolmakers heated pitch distilled from birch trees over a fire to soften it, chewed bits of it into a pliable state, then used the sticky wad to fasten sharpened stones to wooden or bony shafts to make weapons and tools.

Natalija Kashuba, an archaeology Ph.D. student at Uppsala University in Sweden, and colleagues wondered whether any usable DNA from the chewers’ saliva remained inside the hardened resin. Kashuba, who did the work while a student at the University of Oslo, and the rest of the team took tiny samples from three wads, ground them to powder, and put them through an extremely sensitive DNA amplification process designed to locate ancient DNA, which is often highly degraded.

The researchers identified human DNA in all three pieces. Further analysis revealed each came from a different individual—two females and a male. Based on estimations of tooth size and wear taken from the toothmarks in the pitch, the researchers suspect the chewers were young, between 5 and 18 years old. Adult tooth impressions have also been found in pitch from the site, which could suggest an egalitarian toolmaking process involving all sexes and ages, the team reports this week on the bioRxiv preprint server.

The DNA also revealed these pitch chewers belonged to a genetic group known as Scandinavian hunter-gatherers, who hunted reindeer in what are today Sweden and Norway some 8000 years ago. That confirms what anthropologists suspected, says Torsten Günther, an evolutionary biologist at Uppsala University who wasn’t involved in the work. The study’s real value, he says, is highlighting the promise of studying ancient human populations even when you can’t find the humans themselves. “Even if human remains are found, it would be an opportunity to perform these genomic studies without destructive sampling of those human remains.”

Matisoo-Smith cautions that because the wads of pitch in the study weren’t found embedded in actual tools, we can’t be sure the chewers were toolmakers. They may have been children just chewing gum, she suggests. “Either way, it’s pretty cool.”

Author: Michael Price | Source: Science Magazine [December 26, 2018]



Gold coins from Thirty Years’ War found in Czech Republic

An unnamed individual found 60 coins partly buried on a pasture. The discovery was immediately reported and, before publicising the information earlier this week, local experts were asked to look at the objects.

Gold coins from Thirty Years' War found in Czech Republic
Credit: ČTK/Josef Vostárek

One of them is archaeologist David Vích from the Vysoké Mýto Regional Museum. He says the youngest coin dates back to 1631, which suggests the items were likely buried sometime between the mid- to late-period in the war. The region of Pardubice was threatened multiple times during these phases of the conflict, especially by Swedish forces.

“The Thirty Years’ War was a very dramatic period when things were often buried underground and not collected afterwards. Because this is quite a large amount of money, whose composition points to its origins somewhere in the region of Hungary, we may go so far as to hypothesise that it is related to a marching army, or some sort of military action.”

The coins, one of which weighs more than three grams, were likely to have been placed in a leather or textile pouch which rotted away over time.

Aside from Hungarian coins, there are also pieces from Poland, the Netherlands and Turkey. Most are made out of gold with a high purity.

According to numismatist Petr Vorel, the horde would have bought two cows or a good horse at the time. His colleague Ladislav Nekvapil, who works with him at the East Bohemian Museum of Pardubice, says that today the treasure could be sold in the range of seven figure numbers.

Gold coins from Thirty Years' War found in Czech Republic
Credit: ČTK/Josef Vostárek

“We are just beginning to analyse the find properly, so we cannot say exactly what the treasure is worth. However, there are some coins here which would be worth around seven to ten thousand crowns on the collectors’ market and others in the range of tens and even hundreds of thousands of crowns.

“If we were to make a rough estimate the total worth would probably lie in the millions.”

Experts say they are particularly happy that the find was immediately reported and did not end up on the black market, which apparently happens often.

The region’s deputy governor responsible for culture told the Czech News Agency that he is ready to propose a reward worth 10 percent of the total price be given to the person who discovered the coins.

Archaeologist David Vích says the items will certainly be displayed to the public, but expects the earliest opportunity will be in May 2019 when the Vysoké Mýto Regional Museum is holding a museum night.

Author: Tom McEnchroe | Source: Radio Praha [December 26, 2018]



2019 January 8 HESS Telescopes Explore the High-Energy Sky…

2019 January 8

HESS Telescopes Explore the High-Energy Sky
Video Credit & Copyright: Vikas Chander, H.E.S.S. Collaboration; Music: Emotive Piano by Immersive Music

Explanation: They may look like modern mechanical dinosaurs but they are enormous swiveling eyes that watch the sky. The High Energy Stereoscopic System (H.E.S.S.) Observatory is composed of four 12-meter reflecting-mirror telescopes surrounding a larger telescope housing a 28-meter mirror. They are designed to detect strange flickers of blue light – Cherenkov radiation –emitted when charged particles move slightly faster than the speed of light in air. This light is emitted when a gamma ray from a distant source strikes a molecule in Earth’s atmosphere and starts a charged-particle shower. H.E.S.S. is sensitive to some of the highest energy photons (TeV) crossing the universe. Operating since 2003 in Namibia, H.E.S.S. has searched for dark matter and has discovered over 50 sources emitting high energy radiation including supernova remnants and the centers of galaxies that contain supermassive black holes. Pictured last September, H.E.S.S. telescopes swivel and stare in time-lapse sequences shot in front of our Milky Way Galaxy and the Magellanic Clouds – as the occasional Earth-orbiting satellite zips by.

∞ Source: apod.nasa.gov/apod/ap190108.html

PIE Urheimat poll: two or three options left

If we let ancient DNA dictate the terms in the Proto-Indo-European (PIE) homeland debate ahead of historical linguistics and archeology, then, as far as I can see, there are two or three realistic options for the location of the said homeland. Here they are, in order of my own preference:

1) The Don-Caspian steppe around 4,300 BCE (see here). The ancestors of the Hittites and other Anatolian speakers also came from this homeland and entered Anatolia via the Balkans (or, less likely, the Caucasus) in fairly small groups sometime between 4,000 and 2,000 BCE. A lot of samples from Bronze Age Anatolia are needed to confirm or debunk the presence of steppe ancestry there.
2) The eastern Balkans during the peak of the ostentatious Copper Age in the region. Proto-Indo-European developed in the wealthy Chalcolithic communities of the western Black Sea coast and quickly spread both into the steppes and Anatolia via elite and trade contacts, and thus with minimal gene flow. Proto-Indo-European minus Anatolian, or PNIE, then spread from Eastern Europe during the Bronze Age with the mass migrations of the Yamnaya and closely related populations. A lot of samples from Chalcolithic western Anatolia are needed to confirm or debunk that people moved from the Balkans into Anatolia at this time.
3) Transcaucasia and/or nearby around 10,000 BCE. Proto-Indo-European, or rather Indo-Hittite, is much older than generally accepted, and came from the Epipaleolithic northern Near East. It was introduced into the steppes by foragers of the so called Caucasus Hunter-Gatherer (CHG) type, where it eventually became Proto-Indo-European minus Anatolian, or PNIE. Proto-Anatolian was spoken by closely related CHG-like foragers who stayed in the northern Near East.

Admittedly, that last theory is way out there, and at the moment, has about as much chance of being accepted by most historical linguists as Out-of-India. But the one advantage that is has over the other two proposals is that it doesn’t need any additional sampling of ancient DNA.
I’ll probably get grilled in the comments why I didn’t include a proposal with the Maykop culture as the PIE community, or at least the Indo-Europeanizing agent in the steppe. Honestly, after seeing the ancient DNA from a wide range of Maykop remains courtesy of Wang et al., I think the chances that Maykop was an Indo-European-speaking culture are low. Indeed, both the Maykop genome-wide data and uniparental markers scream “Northwest Caucasian” to me.
Also, if the Caucasus was the PIE homeland, or even a major expansion point for early Indo-European languages, then considering its widely accepted status as a linguistic hotspot and refuge, it’s fair to expect that it should still harbor at least one highly diverged Indo-European language. Is there any evidence that it ever did?
Below is an interactive poll. Please vote for one of the three options and feel free to let us know in the comments why you made the choice that you did. I might add more options to the poll if compelling reasons are given in the comments to do so.

PIE Urheimat poll

See also…

Yamnaya: home-grown

Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…
On the doorstep of India


Dragon Packed With Science Before Thursday’s Departure

ISS – Expedition 58 Mission patch.

January 7, 2019

The Expedition 58 crew members are packing the SpaceX Dragon space freighter ahead of its return to Earth on Thursday. Ground controllers are also readying communications gear and robotics systems prior to Dragon’s departure from the International Space Station.

Image above: The SpaceX Dragon cargo craft and the Canadarm2 robotic arm are pictured attached to the International Space Station as the orbital complex was 251 miles above the Atlantic Ocean about to fly over Morocco. Image Credit: NASA.

Astronauts Anne McClain of NASA and David Saint-Jacques of the Canadian Space Agency are wrapping up final transfers of completed science experiments in Dragon today. The duo is loading science samples from several experiments for return to Earth, where they will quickly be delivered to investigators around the country for analysis.

International Space Station (ISS). Animation Credit: NASA

Engineers on the ground are testing communications and control gear that will be used to monitor and command Dragon after its release from the station. Robotics controllers are also powering up the Canadarm2 robotic arm today to grapple Dragon before its removal from the Harmony module.

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

SpaceX Dragon: https://www.nasa.gov/mission_pages/station/structure/launch/spacex.html

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

Harmony module: https://www.nasa.gov/mission_pages/station/structure/elements/harmony

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

Best regards, Orbiter.chArchive link

Hubble takes gigantic image of the Triangulum Galaxy

The sharpest view ever of the Triangulum Galaxy

NGC 604 — a gigantic gas cloud in the Triangulum Galaxy

NGC 595 — a diffuse nebula in the Triangulum Galaxy

Stellar association IC 142

Wide-field view of the Triangulum Galaxy showing the extent of the survey

Area around the Triangulum Galaxy (ground-based image)


Hubblecast 115 Light: Triangulum Galaxy in unrivalled detail

Hubblecast 115 Light: Triangulum Galaxy in unrivalled detail

Zooming in on the Triangulum Galaxy

Zooming in on the Triangulum Galaxy

A close-up look at the Triangulum Galaxy

A close-up look at the Triangulum Galaxy

The NASA/ESA Hubble Space Telescope has captured the most detailed image yet of a close neighbour of the Milky Way — the Triangulum Galaxy, a spiral galaxy located at a distance of only three million light-years. This panoramic survey of the third-largest galaxy in our Local Group of galaxies provides a mesmerising view of the 40 billion stars that make up one of the most distant objects visible to the naked eye.

This new image of the Triangulum Galaxy — also known as Messier 33 or NGC 598 — has a staggering 665 million pixels and showcases the central region of the galaxy and its inner spiral arms. To stitch together this gigantic mosaic, Hubble’s Advanced Camera for Surveys needed to create 54 separate images.

Under excellent dark-sky conditions, the Triangulum Galaxy can be seen with the naked eye as a faint, blurry object in the constellation of Triangulum (the Triangle), where its ethereal glow is an exciting target for amateur astronomers.

At only three million light-years from Earth, the Triangulum Galaxy is a notable member of the Local Group — it is the group’s third-largest galaxy, but also the smallest spiral galaxy in the group [1]. It measures only about 60 000 light-years across, compared to the 200 000 light-years of the Andromeda Galaxy; the Milky Way lies between these extremes at about 100 000 light-years in diameter [2].

The Triangulum Galaxy is not only surpassed in size by the other two spirals, but by the multitude of stars they contain. The Triangulum Galaxy has at least an order of magnitude less stars than the Milky Way and two orders of magnitude less than Andromeda. These numbers are hard to grasp when already in this image 10 to 15 million individual stars are visible.

In contrast to the two larger spirals, the Triangulum Galaxy doesn’t have a bright bulge at its centre and it also lacks a bar connecting its spiral arms to the centre. It does, however, contain a huge amount of gas and dust, giving rise to rapid star formation. New stars form at a rate of approximately one solar mass every two years.

The abundance of gas clouds in the Triangulum Galaxy is precisely what drew astronomers to conduct this detailed survey. When stars are born, they use up material in these clouds of gas and dust, leaving less fuel for new stars to emerge. Hubble’s image shows two of the four brightest of these regions in the galaxy: NGC 595 and NGC 604. The latter is the second most luminous region of ionised hydrogen within the Local Group and it is also among the largest known star formation regions in the Local Group.

These detailed observations of the Triangulum Galaxy have tremendous legacy value — combined with those of the Milky Way, the Andromeda Galaxy and the irregular Magellanic Cloud galaxies, they will help astronomers to better understand star formation and stellar evolution.


[1] Our galaxy, the Milky Way, is part of the Local Group, an assembly of more than 50 galaxies bound together by gravity. Its largest member is the Andromeda Galaxy — also known as Messier 31 — followed by the Milky Way and the Triangulum Galaxy. The remaining members of the Local Group are dwarf galaxies, each orbiting one of the three larger ones. 

[2] The much bigger Andromeda Galaxy was mapped by Hubble in 2015, creating the sharpest and largest image of this galaxy and the largest Hubble image ever (heic1502).



Mathias Jäger
ESA/Hubble, Public Information Officer
Garching, Germany
Tel: +49 176 62397500

Archive link

HiPOD 7 January 2019: Ejecta Margin Near Ares VallisThe …

HiPOD 7 January 2019: Ejecta Margin Near Ares Vallis

The objective of this observation is to examine the margin of a crater’s ejecta. The ejecta on this side looks different than on the opposite side. Ares Vallis is an outflow channel, likely carved by fluids in the distant past.

Date: 12 March 2018

Altitude: 291 km

NASA/JPL/University of Arizona

Baby star’s fiery tantrum could create the building blocks of planets

A massive stellar flare on a baby star has been spotted by University of Warwick astronomers, shedding light on the origins of potentially habitable exoplanets.

Baby star's fiery tantrum could create the building blocks of planets
Artist’s impression of a similar solar flare (a very large flare from EV Lac)
[Credit: Casey Reed/NASA]

One of the largest ever seen on a star of its type, the huge explosion of energy and plasma is around 10,000 times bigger than the largest solar flare ever recorded from our own Sun.

The discovery is detailed in a paper for the Monthly Notices of the Royal Astronomical Society and reveals how this huge ‘tantrum’ could even perturb the material orbiting a star which would create the building blocks for future planets.

The flare was seen on a young M-type star named NGTS J121939.5-355557, located 685 light years away. At around 2 million years old, it is what astronomers refer to as a pre-main sequence star which is yet to reach the size that it spends the majority of its lifecycle.

It was observed as part of a large flare survey of thousands of stars by University of Warwick Ph.D. student James Jackman, as part of a project searching for explosive phenomena on stars outside our solar system. He used the Warwick-led Next-Generation Transit Survey (NGTS) telescope array in Chile which is designed to find exoplanets by collecting brightness measurements of hundreds of thousands of stars and is based at the European Southern Observatory’s Paranal Observatory. His attention was drawn to NGTS J121939.5-355557 as it had one of the largest flares seen in these types of stars.

A stellar flare occurs when the magnetic field of a star rearranges itself, releasing huge amounts of energy in the process. This accelerates charged particles, or plasma, within the star which crash into its surface, heating it up to around 10,000 degrees. That energy produces optical and infra-red light, but also x-rays and gamma rays that can be picked up by telescopes on Earth and in orbit.

Magnetic fields on M stars are a lot stronger than those on our own sun and the astronomers calculated that this size of flare is a rare event, occurring anywhere from every three years to twice a decade.

James, who is studying in the University of Warwick’s Department of Physics, said: “This is normally a star that shows little activity and stays a constant brightness. Then, on this one particular night, we saw it suddenly grow seven times brighter than normal for a few hours, which is pretty extreme. And then after that it goes back to normal.

“We see these types of flares on the Sun, but no-where near as big as this. On our Sun, you can do incredibly detailed studies on this kind of activity. It’s difficult to extend that understanding to other stars because the data we need hasn’t been available until now.

“This is an incredibly young star, only about 2 million years old. You’d call it a baby – it’s going to live for ten of billions of years, so it’s in the first one percent of its lifetime. Even though it’s much cooler than our Sun by about 2000 degrees it is roughly the same size, but pretty large for an M star. This is because it’s still being formed from gas in the disc and contracting and cooling until it reaches the main sequence, staying at a certain radius and luminosity for billions of years.

“Finding out these kinds of details has only been possible thanks to the Gaia mission that began earlier this year.”

The X-rays from these large flare events are thought to affect the formation of ‘chondrules,’ flash-melted calcium-aluminium-rich grains in the star’s protoplanetary disc. These gather together into asteroids that eventually coalesce into orbiting planets. The study adds to our understanding of how flares ‘perturb’ the protoplanetary disc, moving around the material that impacts on planet formation and affecting the eventual structure of a planetary system.

Professor Peter Wheatley, James’s Ph.D. supervisor, said: “A massive flare like this could be advantageous for planet formation, or it could be disruptive. This particular star won’t have formed its planets yet so this type of flare activity is something that astronomers will need to take into account when considering planet formation.

“There’s a discussion at the moment around whether flares are a good or bad thing for life on orbiting habitable planets, because they output a large amount of UV radiation. That could cause biological damage to surface organisms and damage their DNA. On the other hand, UV radiation is required for various chemical reactions to start life and that’s not typically provided in great enough quantity by these types of stars. These flares could potentially kickstart these reactions.”

Author: Peter Thorley | Source: University of Warwick [December 21, 2018]




    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...