пятница, 12 июля 2019 г.

Moon mission for an Indian probe



ISRO — Indian Space Research Organisation logo.


July 12, 2019


A few days before the 50th anniversary of the arrival of the first men on the Moon, Mumbai will launch a device on the star of the night.


India launches its second lunar mission on Monday with the objective of becoming the fourth nation to set a plane on the moon, a big step for its thrifty but ambitious space program.


A few days before the fiftieth anniversary of the arrival of the first men on the moon, the Indian space agency ISRO plans to launch on Monday July 15 at 02:51 local (23:21 Sunday) its Chandrayaan-2 mission from the firing point of Sriharikota (south-east from India).


New Delhi has spent $ 140 million — much less than other major space agencies for missions like this — on this expedition to land a lander and a mobile robot on September 6 at the south pole of the natural satellite. located some 384,000 kilometers from the Earth.



Chandrayaan-2 («Lunar Trolley» in Hindi) will consist of an orbiter, an undercarriage and a rover, for a total weight of 3.8 tons. The whole will be propelled into the atmosphere by a rocket GSLV-MkIII, the most powerful Indian launcher, equivalent to a European rocket Ariane 5.


The fifteen minutes of the final descent of the lander Vikram, planned to land on a high plateau between the craters Manzinus C and Simpelius N, «will be the most terrifying moments because we have never undertaken such a complex mission,» K. Sivan, the director of ISRO, recently told the press.


If the mission goes according to plan, India would become the fourth country in the world — after the Soviet Union, the United States and China — to successfully pose a device on the moon. An Israeli probe missed its moon landing in April.



A 27-kilogram Indian rover, Pragyan, should then tread the lunar soil in search of traces of water and «fossil signs of the early solar system,» according to ISRO.


The vehicle will run on solar energy and should be able to walk on a lunar day, fourteen days on land. It can travel up to 500 meters.


International influence


This Indian mission is part of a renewed international interest for the Moon. The man, who strode for the last time in 1972, is preparing for his return. The US government has asked NASA to return astronauts for 2024.


The return to the Moon is seen as an essential step in the preparation of manned flights to more distant destinations, in the foreground of which the planet Mars.


The Chandrayaan-2 project is the second lunar mission of the South Asian giant, who had placed a probe in orbit around the moon during the Chandrayaan-1 mission eleven years ago.



The Indian space program has been noted in recent years by its combination of ambition and budget sobriety, with operating costs well below those of its counterparts, as well as its progression at no charge.


ISRO is planning to send a crew of three astronauts into space by 2022, which would be his first manned flight. Its scientists are also working on the development of its own space station, expected over the next decade.


The current Indian Prime Minister, the Hindu nationalist Narendra Modi, pays particular attention to the space program. Beyond scientific research, he sees it as a lever of international influence and constitutive of a great national narrative on the rise of his country of 1.3 billion people.




«A spacecraft mission of the complexity of Chandrayaan-2 sends the message that India is capable of accomplishing difficult technological development endeavors,» said Amitabha Ghosh, a scientist who collaborated on NASA’s Martian missions.


Expert space at the New Delhi Observer Research Foundation, Rajeswari Pillai Rajagopalan believes Chandrayaan-2 will enhance India’s prestige «at a time when international space programs, and especially Asian programs, are increasingly competing «.


For more informations about ISRO and Chandrayaan-2 mission, visit:


Indian Space Research Organisation (ISRO): https://www.isro.gov.in/


Chandrayaan-2 mission: https://www.isro.gov.in/chandrayaan2-home-0


Images, Text, Credits: AFP/ISRO/Orbiter.ch Aerospace/Roland Berga.


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Bird-like dinosaur is oldest unearthed in North America

A team of palaeontologists from the UK and US have identified a one of a kind 150 million year old dinosaur skeleton. The specimen has been classified as a new species to science with the discovery also raising questions about the evolution of avian flight.











Bird-like dinosaur is oldest unearthed in North America
Credit: University of Manchester

During the summer of 2001, the skeleton was discovered while removing overlying rock during the excavation of Wyoming’s longest dinosaur, Supersaurus. The quarry was located the steep slopes of the famous Morrison Formation. Most dinosaur fans will be familiar with other Morrison Formation celebrities such as Stegosaurus, Diplodocus and Allosaurus. This new chicken-sized, carnivorous dinosaur lived in a world populated by giants. It is the smallest dinosaur ever found in Wyoming.


Co-author of the study, Bill Wahl, who is the preparation laboratory manager at the Wyoming Dinosaur Centre and the palaeontologist who found and collected the specimen, recalled just how exciting the find was: «We were removing a ledge of overburden rock and found—unfortunately with a shovel—some tiny, delicate bones poking out. We immediately stopped, collected as much of the bones as possible and spent the next few days frantically searching for more. Only after some of the bones were cleaned did we realise that we had found something spectacular.»


In 2005, the specimen was donated to the Big Horn Basin Foundation, a research and educational non-profit that in 2016 merged with the Wyoming Dinosaur Centre to form a new non-profit foundation, where the specimen is now curated.


The specimen has been known in scientific circles for several years, but only by its nickname ‘Lori’, or as ‘the Lori specimen’. Yet, it had remained the subject of unpublished research until now. The study was published in PeerJ, co-author Dean Lomax is a palaeontologist and visiting scientist at The University of Manchester who first saw the specimen in 2008 (then aged 18).











Bird-like dinosaur is oldest unearthed in North America
Credit: University of Manchester

«I remember the first time I laid my eyes on this little dinosaur. Even back then, I knew it was a significant discovery. But, it wasn’t until 2015 when our dino team formed and we began to study ‘Lori’ in much more detail than ever before. In fact, the project took a major step forward with a successful crowdfunding campaign launched through experiment.com in 2016, for which we are grateful to everybody who kindly donated and helped make this project happen».


Lori has also now received its formal, scientific name, Hesperornithoides miessleri. Hesperornithoides is a combination of ‘Hesper’, referring to the discovery in the American West, and ‘ornis’ for the bird-like form of the dinosaur, whereas the species name honours the Miessler family, whose land the specimen was found on and who have been avid supporters of the project.


One of the other key findings of the study relates to the origin of avian (bird) flight. In particular, Hesperornithoides is a highly terrestrial proto-bird, suggesting that many features we associate with being bird-like evolved in dinosaurs that lived out their lives on the ground.


Lead author and Ph.D. candidate at The University of Wisconsin-Madison, Scott Hartman said: «We wanted to expand the dataset used to test dinosaur-bird relationships, so we added hundreds of new species and tens of thousands of new characters. We found that Lori is a primitive member of a group of dinosaurs that includes Troodon, but perhaps more importantly we discovered that the smaller details of the family tree of bird-like dinosaurs isn’t quite as resolved as some researchers would claim.»


Hartman continued: «For example, it only takes a few changes in the dataset for Hesperornithoides to be found as a closer relative of Velociraptor than of Troodon. One robust finding we did come up with is that even as the interrelationships changed, the primitive members of all these groups were non-flying ground dwelling dinosaurs. That means that some small relatives of Velociraptor such as Microraptor that looks like it could have glided evolved this separately from the modern bird family.»


Source: University of Manchester [July 11, 2019]



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New species of lizard found in stomach of microraptor

A team of paleontologists led by Prof. Jingmai O’Connor from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, together with researchers from the Shandong Tianyu Museum of Nature, have discovered a new specimen of the volant dromaeosaurid Microraptor zhaoianus with the remains of a nearly complete lizard preserved in its stomach. Their findings were published in Current Biology.











New species of lizard found in stomach of microraptor
A new lizard species in the abdomen of a specimen of Microraptor
[Credit: Jingmai O’Connor]

The lizard is unlike any previously known from the Cretaceous and represents a new species, Indrasaurus wangi. The lizard was named after Prof. WANG Yuan from IVPP, who is also director of the Paleozoological Museum of China. Prof. WANG is an expert on the paleoherpetofauna of China and has been in charge of numerous exhibitions of Chinese fossils.


The name Indrasaurus was inspired by a Vedic legend in which the god Indra was swallowed by a dragon during a great battle (the dragon here referring to Microraptor).


Dr. DONG Liping, a former student of Prof. WANG’s, ran the most extensive phylogenetic analysis of Cretaceous lizards ever conducted and showed that all known Cretaceous species were more closely related to each other than to any modern lineage. The new lizard had teeth unlike any other previously known from the Jehol Biota, thus expanding the diversity of this clade and possibly suggesting a unique diet for this new species.


This is the fourth documented occurrence of a Microraptor preserving stomach contents — this dinosaur is now known to have fed on mammals, birds, fish, and lizards, supporting the interpretation that it was an opportunistic predator.











New species of lizard found in stomach of microraptor
Illustration of the lizard-swallowing Microraptor
[Credit: Doyle Trankina]

The lizard is nearly complete and articulated, showing that it was swallowed whole and head first, meaning that Microraptor fed in a manner similar to living carnivorous birds and lizards.


Although the Jurassic troodontid Anchiornis has been recently demonstrated to have egested pellets similar to extant carnivorous birds (most famously documented in owls), this ability was apparently absent in Microraptor, further adding to the evidence that the evolutionary transition from dinosaur to bird was characterized by extreme homoplasy — that is, numerous traits evolved multiple times independently in closely related groups.


Over the past 20 years, direct evidence of trophic interactions in the Jehol Biota has slowly accumulated. There are now 20 predator-prey relationships documented through direct evidence of stomach contents.


The authors used these relationships to reconstruct the first Jehol food web. Although certainly preliminary, this food web indicates that fish formed the most important food source for secondary and tertiary consumers. This food web can be used in the future to better understand the Jehol ecosystem.


Source: Chinese Academy of Sciences [July 11, 2019]



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Ancient genomics pinpoint origin and rapid turnover of cattle in the Fertile Crescent

The keeping of livestock began in the Ancient Near East and underpinned the emergence of complex economies and then cities. Subsequently, it is there that the world’s first empires rose and fell. Now, ancient DNA has revealed how the prehistory of the region’s largest domestic animal, the cow, chimes with these events.











Ancient genomics pinpoint origin and rapid turnover of cattle in the Fertile Crescent
A zebu-shaped weight from Tel Beth-Shemesh [Credit: A. Hay, Tel Beth-Shemesh Excavations]

An international team of geneticists, led by those from Trinity College Dublin, have deciphered early bovine prehistory by sequencing 67 ancient genomes from both wild and domestic cattle sampled from across eight millennia.


«This allowed us to look directly into the past and observe genomic changes occurring in time and space, without having to rely on modern cattle genetic variation to infer past population events,» said Postdpoctoral Researcher at Trinity,Marta Verdugo, who is first author of the article that has just been published in leading international journal Science.


The earliest cattle are Bos taurus, with no ancestry from Bos indicus, or zebu — herds which were from a different origin in the Indus Valley. «However, a dramatic change occurred around 4,000 years ago when we detect a widespread, wholesale influx of zebu genetics from the east,» added Verdugo.


The rapid influx that occurred at this point — despite Near Eastern Bos taurus and zebu having coexisted for previous millennia — may be linked to a dramatic multi-century drought that was experienced across the greater Near East, referred to as the 4.2-thousand years ago climate event. At this time the world’s first empires in Mesopotamia and Egypt collapsed and breeding with arid-adapted zebu bulls may have been a response to changing climate by ancient herders.


Professor of Population Genetics at Trinity, Dan Bradley, said: «This was the beginning of the great zebu diaspora that continues to the present day — descendants of ancient Indus Valley cattle are herded in each continental tropics region today.»


Sequencing Near Eastern wild cattle, or aurochs, also allowed the team to unpick the domestication of this most formidable of beasts. Whereas their similarity to the early cattle of Anatolia concurs with a primary origin there, it is clear that different local wild populations also made significant additional genetic contributions to herds in Southeast Europe and also in the southern Levant, adding to the distinctive make up of both European and African populations today.


«There is a great power in ancient genomics to uncover new, unforeseen tales from our ancient history,» added Professor Bradley.


Source: Trinity College Dublin [July 11, 2019]



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The world’s oldest autograph by a Christian is in Basel

A letter in the Basel papyrus collection describes day-to-day family matters, and yet is unique in its own way: It provides valuable insights into the world of the first Christians in the Roman Empire, which is not recorded in any other historical source. The letter has been dated to the 230s AD, and is thus older than all previously known Christian documentary evidence from Roman Egypt.











The world's oldest autograph by a Christian is in Basel
The papyrus P.Bas. 2.43 has been in the possession of the University of Basel for over 100 years. The letter
 has been dated to the 230s AD and is thus older than all previously known Christian documentary
evidence from Roman Egypt [Credit: University of Basel]

The earliest Christians in the Roman Empire are usually portrayed as eccentrics who withdrew from the world and were threatened with persecution. This is countered by the contents of the Basel papyrus letter P.Bas. 2.43. The letter contains indications that in the early third century, Christians were living outside the cities in the Egyptian hinterland, where they held political leadership positions and blended with their pagan environment in their everyday lives.
A family with Christian beliefs


The papyrus P.Bas. 2.43 has been in the possession of the University of Basel for over 100 years. It is a letter from a man named Arrianus to his brother Paulus. The document stands out from the mass of preserved letters of Graeco-Roman Egypt by its concluding greeting formula: After reporting on day-to-day family matters and asking for the best fish sauce as a souvenir, the letter writer uses the last line to express his wish that his brother will prosper «in the Lord.» The author uses the abbreviated form of the Christian phrase «I pray that you fare well ‘in the Lord’.»


«The use of this abbreviation—known as a nomen sacrum in this context—leaves no doubt about the Christian beliefs of the letter writer,» says Sabine Huebner, professor of ancient history at the University of Basel. «It is an exclusively Christian formula that we are familiar with from New Testament manuscripts.»


The name of the brother is also revealing, Prof. Huebner says: «Paulus was an extremely rare name at that time, and we may deduce that the parents mentioned in the letter were Christians and had named their son after the apostle as early as 200 AD.»











The world's oldest autograph by a Christian is in Basel
English Transcript Papyrus P.Bas. 2.43 [Credit: University of Basel]

Determining date and origin


By means of extensive prosopographical research, Huebner was able to trace the papyrus to the 230s AD. This makes the letter at least 40 to 50 years older than all other known Christian documentary letters worldwide. It also provides important details on the social background of this early Christian family: Arrianus and his brother Paulus were young, educated sons of the local elite, landowners and public officials.


The location of the papyrus was also successfully reconstructed: It comes from the village of Theadelphia in central Egypt and belongs to the famous Heroninus archive, the largest papyrus archive from Roman times.


The papyrus letter is at the heart of Huebner’s new monograph, Papyri and the Social World of the New Testament. Her book is aimed at a broad audience and shows that the papyri of Greco-Roman Egypt can help to illustrate the social, political and economic life of the early Christians. Furthermore, this year, all Basel papyri will appear in a first edition in the supplements of the Archiv für Papyrusforschung. The digital publication appeared in June 2019 on the international database Papyri.info.


The Basel Papyrus Collection


In 1900, the University of Basel was one of the first German-speaking universities and the first in German-speaking Switzerland to procure a papyrus collection. At that time, papyrology was booming—people hoped to discover more about the development of early Christendom and to rediscover works of ancient authors believed to be lost. The Voluntary Museum Association of Basel provided CHF 500 to purchase the papyri, an amount equivalent to around CHF 5,000 today.


The Basel collection contains 65 documents in five languages from the Ptolemaic and Roman periods and late antiquity. Most of the collection is made up of documentary papyri, which are primarily of social, cultural and religious historical interest as they record the daily life of ordinary people 2,000 years ago. Most of the Basel papyri have not been published and remained largely ignored by research until now. The three-year editorial project led by Prof. Huebner was funded by the Swiss National Science Foundation and carried out in collaboration with the Digital Humanities Lab of the University of Basel.


Source: University of Basel [July 11, 2019]



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Island cores unravel mysteries of ancient Maltese civilisation

The mysteries of an ancient civilisation that survived for more than a millennium on the island of Malta—and then collapsed within two generations—have been unravelled by archaeologists who analysed pollen buried deep within the earth and ancient DNA from skulls and bones.











Island cores unravel mysteries of ancient Maltese civilisation
The Ġgantija temples of Malta are among the earliest free-standing buildings known
[Credit: Bs0u10e01, licensed under CC BY-SA 4.0]

It’s part of a field of work that is expanding the use of archaeological techniques into environments where they were previously thought to be unusable.


The Temple Culture of the Maltese archipelago in the Mediterranean began nearly 6,000 years ago and at its height probably numbered several thousand people—far denser than the people of mainland Europe could manage at the time. The island people constructed elaborate sacred sites, such as the famous Ġgantija temple complex, and their buildings are among the earliest free-standing buildings known. But, after 1,500 years, they were gone.


Professor Caroline Malone, prehistory specialist at Queen’s University Belfast, Northern Ireland, wanted to understand how the fragile island ecology sustained the people for so long despite drought, violent storms and soil erosion—and why it ultimately failed.


She ran an ambitious project, Fragsus, which drew on multiple tools to find some answers. Scientists drilled earth cores ranging from eight to 30 metres deep, dating the sediment using carbon dating to understand which time period it referred to.


They counted the pollen at 2cm intervals and analysed individual pollen grains using chemical signatures imprinted by the surrounding environment to understand what nutrients the parent plants were absorbing from the ground. Molluscs embedded in the soil revealed glimpses of the landscape since ‘snails are very particular about where they live and don’t move far,» said Prof. Malone.


Meanwhile, other specialists assessed the wear and tear on tens of thousands of human bones from a burial site to understand the islanders’ lifestyles. The team broke new ground by analysing bone with a technique called ancient DNA (aDNA) analysis, says Prof. Malone. It had previously been thought that the warmth of any climate south of the Alps would destroy such old DNA. But it turned out that skulls buried at a relatively cool five metres’ depth still harboured aDNA within thick bone behind the ear.


Erosion


From what they’ve uncovered, the team thinks that these people understood the importance of soil management to fend off starvation. Within a hundred years of their arrival on the tiny, 316 square km archipelago they had felled most of the trees, exposing the ground to drastic erosion.


To survive, they reared dairy animals rather than prioritising meat—killing off newborn livestock before they had a chance to graze. They mixed livestock manure back into the soil and may even have made back-breaking journeys carting soil washed into the valleys back uphill to refresh the upland fields.


The evidence for this lies in strange, parallel ruts in the ground that may be cart tracks, as well as signs from the skeletons that soft tissue had sometimes been worn completely away by hard, repetitive activity. Oddly, says Prof. Malone, they ate almost no fish.











Island cores unravel mysteries of ancient Maltese civilisation
Malta’s lost civilisation only lasted 1,500 years but it produced
some of the oldest buildings still standing today
[Credit: Horizon]

To achieve such complex collaborative effort something powerful must have held the community together: the temples.


Until now, the Temple Culture was thought to have centred on the worship of a mother goddess, but Prof. Malone thinks it was more of a clubhouse culture, focused on ritual and feasting but where food—rather than a deity—was revered. In the complexes it is now clear that the people displayed their livestock and harvests on special benches and altars, feasted, and also stored food.


There is no skeletal evidence of violent death and no fortifications, said Prof. Malone. Instead the society appears to have survived through cooperation and sharing.


Deficiencies


Despite the society’s strength and success, as centuries passed the soil erosion and climate conditions worsened, as evidenced by the different types of pollen in the soil, the diminishing number of tree remains and the human bones wracked with evidence of dietary deficiencies.


In the final centuries of the Temple Culture, between 2600 BC and 2400 BC, half of those dying were children.


Other factors likely contributed, said Prof. Malone. Adult skulls from this time are greatly varied, their DNA indicating the arrival of immigrants from as far as the Eurasian Steppes and sub-Saharan Africa, possibly causing population pressure and new diseases.


The decisive blow may have been an unknown catastrophe that occurred around 2350 BC, a period during which, according to tree ring analysis, the whole region suffered a catastrophic climate event—possibly a dust cloud caused by a volcanic eruption.


Laboratories


Islands can be used as laboratories for understanding change in the wider world, said Prof. Malone. However, the geographical peculiarities of islands can also present problems by rendering conventional research techniques redundant. In Spain’s Canary Islands, for example, ancient pollen is not well-preserved in the local terrain. What’s more, many important plants on the islands—such as its emblematic laurel trees—produce no, or little, pollen, and the environmental conditions have also eroded other pieces of evidence, such as macrofossils.











Island cores unravel mysteries of ancient Maltese civilisation
Palaeo environmental DNA in sediment cores is providing a long term perspective
of how Spain’s Canary Islands weathered past climate change
[Credit: Lea de Nascimento]

Dr. Lea de Nascimento, a specialist in ecology at the Universidad de La Laguna in Tenerife said: «We lack (good preservation of) all the conventional proxies.»


She wants to piece together the history of vegetation on the Canaries—in particular, what they were like before humans arrived over 2,000 years ago. To do so, she is using a new palaeoecological technique called palaeoenvironmental DNA analysis.


eDNA


Environmental DNA (eDNA) is left in soil or water by microorganisms, plant and animal species, and scientists increasingly scan for it to find out what’s going on in today’s environment. It is a relatively new palaeoecological tool, which has so far been used in the coldest and driest places because of its vulnerability to warmth and humidity. But Dr. de Nascimento is now probing for it in core samples spanning several thousand years from the islands.


For the ISLANDPALECO project, she has spent two years learning from experts at a dedicated laboratory in New Zealand how to search for palaeo environmental DNA in sediment cores. After a year of setbacks, she has now found 100-year-old DNA of a much richer variety than can be found in the pollen record. She is still hoping to retrieve older palaeo environmental DNA.


«If you have a long perspective you will know the resilience of ecosystems,» she said. «It will help us understand how an ecosystem will react if we keep putting pressure on it in the future—or in response to climate change.»


She says that knowing more about past ecosystems will also help today’s conservationists restore landscapes depleted by humans and the animals they brought with them.


«The problem is you could invest a lot of money restoring an ecosystem that was never there,» she said.


Author: Aisling Irwin | Source: Horizon: The EU Research & Innovation Magazine [July 11, 2019]



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Climate change threatens Greenland’s archaeological sites: study

In Greenland, climate change isn’t just a danger to ecosystems but also a threat to history, as global warming is affecting archaeological remains, according to a study published Thursday.











Climate change threatens Greenland's archaeological sites: study
Students and scientists investigate materials found at the Norse site Iffiartarfik
[Credit: Roberto Fortuna, National Museum of Denmark]

There are more than 180,000 archaeological sites across the Arctic, some dating back thousands of years, and previously these were protected by the characteristics of the soil.


«Because the degradation rate is directly controlled by the soil temperature and moisture content, rising air temperatures and changes in precipitation during the frost-free season may lead to a loss of organic key elements such as archaeological wood, bone and ancient DNA,» the report, published in the scientific journal Scientific Reports, stated.


The team behind the study, led by Jorgen Hollesen, has been examining seven different sites around the vast Arctic territory’s capital Nuuk, since 2016.


In addition to organic elements, such as hair, feathers, shells and traces of flesh, some of the sites contain the ruins of Viking settlements.











Climate change threatens Greenland's archaeological sites: study
Greenland’s many kitchen middens sites consist of several layers of bones, worn-out tools and other items that the
prehistoric people considered to be garbage [Credit: Roberto Fortuna, National Museum of Denmark]

Projections used in the study, which are based on different warming scenarios, predict that average temperature could increase by up to 2.6 degrees Celsius (4.7 degrees Fahrenheit), leading to «higher soil temperatures, a longer thaw season, and increased microbial activity within the organic layers».


«Our results show that 30 to 70 percent of the archaeological fraction of organic carbon (OC) could disappear within the next 80 years,» Hollesen told AFP.


This means that these remains, some of which provide a unique insight into the lives of the first inhabitants of Greenland from around 2,500 BC, are at risk.


When comparing their findings with previous surveys of the sites they found evidence of degradation already ongoing.











Climate change threatens Greenland's archaeological sites: study
One of the finds was this hand-carved bone point [Credit: Roberto Fortuna
National Museum of Denmark]

«At some sites we did not find any intact bones or pieces of wood, suggesting that these have disintegrated within the last decades,» Hollesen said.


Hollesen added that remains of organic material are being broken down by microbes, but their activity could be slowed down if precipitation increased.


«More rainfall would be good and less rainfall, bad,» he said explaining that «if the organic layers remain wet less oxygen will be available for the microbes that degrade the organic materials».


In other Arctic regions, such as Alaska, hundreds of ancient artifacts have recently emerged as the permafrost, the layer of earth that is frozen all year, thaws due to rising temperatures.


Source: AFP [July 11, 2019]



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Fluorite Quartz & Feldspar Group | #Geology #GeologyPage…


Fluorite Quartz & Feldspar Group | #Geology #GeologyPage #Mineral


Locality: Erongo Mountains, Erongo Region, Namibia


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Bloody Brains Your brain accounts for 2% of your body weight…


Bloody Brains


Your brain accounts for 2% of your body weight but draws a staggering 20% of your blood supply. This requires a vast network of blood vessels, a network whose growth during development is regulated by signalling proteins, including Wnts and Frizzleds. Wnts on nerve cells bind to Frizzleds on blood vessels to direct their growth. But there are many different Wnts and Frizzleds, so how is the right match made? Researchers honed in on Reck, a protein known to enhance Wnt7 signalling, and genetically altered its gene in mice. Two mutations in particular impaired Reck’s ability to enhance Wnt7a signalling. Fluorescence microscopy of sections through mouse brains (pictured) revealed that mutants (bottom) had severe defects in the development of their blood vessels (pink) and therefore their nerve cells (green) when compared to normal mice (top). This adds one more piece to the puzzle of how our brain’s blood supply develops.


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2019 July 12 Magellanic Galaxy NGC 55 Image Credit &…


2019 July 12


Magellanic Galaxy NGC 55
Image Credit & Copyright: AcquisitionEric Benson, ProcessingDietmar Hager


Explanation: Irregular galaxy NGC 55 is thought to be similar to the Large Magellanic Cloud (LMC). But while the LMC is about 180,000 light-years away and a well-known satellite of our own Milky Way Galaxy, NGC 55 is more like 6 million light-years distant, a member of the Sculptor Galaxy Group. Classified as an irregular galaxy, in deep exposures the LMC itself resembles a barred disk galaxy. Spanning about 50,000 light-years, NGC 55 is seen nearly edge-on though, presenting a flattened, narrow profile in contrast with our face-on view of the LMC. Just as large star forming regions create emission nebulae in the LMC, NGC 55 is also seen to be producing new stars. This highly detailed galaxy portrait highlights a bright core crossed with dust clouds, telltale pinkish star forming regions, and young blue star clusters in NGC 55.


∞ Source: apod.nasa.gov/apod/ap190712.html


‘Moon-forming’ Circumplanetary Disk Discovered in Distant Star System


Artist impression of the circumplanetary disk recently discovered around a young planet in the PDS 70 star system. Credit: NRAO/AUI/NSF, S. Dagnello. Hi-Res File



ALMA image of the dust in PDS 70, a star system located approximately 370 light-years from Earth. Two faint smudges in the gap region of this disk are associated with newly formed planets. One such concentration of dust is a circumplanetary disk, the first such feature ever detected around a distant star. Credit: ALMA (ESO/NAOJ/NRAO); A. Isella. Hi-Res File



Composite image of PDS 70. Comparing new ALMA data to earlier VLT observations, astronomers determined that the young planet designated PDS 70 c has a circumplanetary disk, a feature that is strongly theorized to be the birthplace of moons. Credit: ALMA (ESO/NAOJ/NRAO) A. Isella; ESO. Hi-Res File



Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have made the first-ever observations of a circumplanetary disk, the planet-girding belt of dust and gas that astronomers strongly theorize controls the formation of planets and gives rise to an entire system of moons, like those found around Jupiter.


Atacama Large Millimeter/submillimeter Array (ALMA)Funded by the U.S. National Science Foundation and its international partners (NRAO/ESO/NAOJ), ALMA is among the most complex and powerful astronomical observatories on Earth or in space. The telescope is an array of 66 high-precision dish antennas in northern Chile.


This never-before-seen feature was discovered around one of the planets in PDS 70, a young star located approximately 370 light-years from Earth. Recently, astronomers confirmed the presence of two massive, Jupiter-like planets there. This earlier discovery was made with the European Southern Observatory’s Very Large Telescope (VLT), which detected the warm glow naturally emitted by hydrogen gas accreting onto the planets.


The new ALMA observations instead image the faint radio waves given off by the tiny (about one tenth of a millimeter across) particles of dust around the star.


The ALMA data, combined with the earlier optical and infrared VLT observations, provide compelling evidence that a dusty disk capable of forming multiple moons surrounds the outermost known planet in the system.


“For the first time, we can conclusively see the telltale signs of a circumplanetary disk, which helps to support many of the current theories of planet formation,” said Andrea Isella, an astronomer at Rice University in Houston, Texas, and lead author on a paper published in the Astrophysical Journal, Letters.


“By comparing our observations to the high-resolution infrared and optical images, we can clearly see that an otherwise enigmatic concentration of tiny dust particles is actually a planet-girding disk of dust, the first such feature ever conclusively observed,” he said. According to the researchers, this also is the first time that a planet has been clearly seen in these three distinct bands of light.


Unlike the icy rings of Saturn, which likely formed by the crashing together of comets and rocky bodies relatively recently in the history of our solar system, a circumplanetary disk is the lingering remains of the planet-formation process.


The ALMA data also revealed two distinct differences between the two newly discovered planets. The closer in of the two, PDS 70 b, which is about the same distance from its star as Uranus is from the Sun, has a trailing mass of dust behind it resembling a tail. “What this is and what it means for this planetary system is not yet known,” said Isella. “The only conclusive thing we can say is that it is far enough from the planet to be an independent feature.”


The second planet, PDS 70 c, resides in the exact same location as a clear knot of dust seen in the ALMA data. Since this planet is shining so brightly in the infrared and hydrogen bands of light, the astronomers can convincingly say that a fully formed planet is already in orbit there and that nearby gas continues to be syphoned onto the planet’s surface, finishing its adolescent growth spurt.


This outer planet is located approximately 5.3 billion kilometers from the host star, about the same distance as Neptune from our Sun. Astronomers estimate that this planet is approximately 1 to 10 times the mass of Jupiter. “If the planet is on the larger end of that estimate, it’s quite possible there might be planet-size moons in formation around it,” noted Isella.


The ALMA data also add one more important element to these observations.


Optical studies of planetary systems are notoriously challenging. Since the star is so much brighter than the planets, it is difficult to filter out the glare, much like trying to spot a firefly next to a search light. ALMA observations, however, don’t have that limitation since stars emit comparatively little light at millimeter and submillimeter wavelengths.


“This means we’ll be able to come back to this system at different time periods and more easily map the orbit of the planets and the concentration of dust in the system,” concluded Isella. “This will give us unique insights into the orbital properties of solar systems in their very earliest stages of development.”


The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.




Contact:

Charles E. Blue: Public Information Officer
cblue@nrao.edu;
434-296-0314



Reference: 


“Detection of continuum submillimeter emission associated with candidate protoplanets,” A. Isella, et al., the Astrophysical Journal Letters: apjl.aas.org; Preprint: https://arxiv.org/abs/1906.06308


The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).



ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.



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Throwback Thursday: Apollo 11 FAQ Edition

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With the help of the NASA History Office, we’ve identified some of the most frequently asked questions surrounding the first time humans walked on the surface of another world. Read on and click here to check out our previous Apollo FAQs. 


How many moon rocks

did the Apollo crews bring back? What did we learn?


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The six crews that landed on the Moon brought back 842

pounds (382 kilograms) of rocks, sand and dust from the lunar surface. Each

time, they were transferred to Johnson Space Center’s Lunar Receiving Laboratory, a

building that also housed the astronauts during their three weeks of

quarantine. Today the building now houses other science divisions, but the lunar samples are

preserved in the Lunar Sample Receiving Laboratory.


Built in 1979, the laboratory is the chief repository of the

Apollo samples.


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From these pieces of the Moon we learned that its chemical makeup

is similar to that of Earth’s, with some differences. Studying the samples has yielded clues to the origins of the solar system. In March of 2019, we announced that three cases of pristine Moon samples will be unsealed for the first time in 50 years so that we can take advantage of the improved technology that exists today! 


Did you know you might not have to travel far to see a piece of the Moon up close? Visit our Find a Moon Rock page to find out where you

can visit a piece of the Moon.


What did Apollo astronauts

eat on their way to the Moon?


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Astronaut food has come a long way since the days of Project

Mercury, our first human spaceflight program that ran from 1958-1963. Back then, astronauts “enjoyed” food in cube form or squeezed out of tubes. Early astronaut food menus were designed less for flavor and more for nutritional value, but that eventually shifted as technology evolved. Astronauts today can enjoy whole foods like apples, pizza and even tacos. 


Apollo crews were the first to have hot water, making it easier

to rehydrate their foods and improve its taste. They were also the first to use a “spoon bowl,” a plastic container that was somewhat like eating out

of a Ziploc bag with a spoon. Here’s an example of a day’s menu for a voyage to the Moon:


Breakfast: bacon squares, strawberry cubes and an orange

drink.


Lunch: beef and potatoes, applesauce and a brownie.


Dinner: salmon salad, chicken and rice, sugar cookie cubes

and a pineapple grapefruit drink.


What did Michael Collins do while he orbited the Moon, alone in the Command Module?


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As Neil Armstrong and Buzz Aldrin worked on the lunar surface, Command Module pilot Michael Collins orbited the Moon, alone, for the next 21.5 hours. On board he ran systems checks, made surface observations and communicated with Mission Control when there wasn’t a communications blackout. Blackouts happened every time Collins went behind the Moon. In 2009, Collins wrote this in response to a flurry of media questions about the 40th anniversary of the mission:





Q. Circling the lonely Moon by yourself, the loneliest person in the universe, weren’t you lonely?


A. No. Far from feeling lonely or abandoned, I feel very much a part of what is taking place on the lunar surface. I know that I would be a liar or a fool if I said that I have the best of the three Apollo 11 seats, but I can say with truth and equanimity that I am perfectly satisfied with the one I have. This venture has been structured for three men, and I consider my third to be as necessary as either of the other two.”


What will Artemis astronauts bring back when they land on the Moon?


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Artemis missions to the Moon will mark humanity’s first permanent presence on another world. The first woman and the next man to explore the lunar surface will land where nobody has ever attempted to land before – on the Moon’s south pole where there are billions of tons of water ice that can be used for oxygen and fuel.


We don’t know yet what astronauts will bring back from this unexplored territory, but we do know that they will return with hope and inspiration for the next generation of explorers: the Artemis generation.


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


Global25 workshop 4: a neighbour joining tree of ancient and present-day West Eurasian...

Phylogenetic trees are easy to produce, but there’s an infinite number of ways to run them, and, depending on the input data you’re using, some methods are a lot more effective than others. In this tutorial I’m going to demonstrate one method that has worked well for me when looking at the fine scale genetic relationships between ancient and present-day human populations with my Global25 data.
To get started download this datasheet, plug it into the PAST program, which is freely available here, then select all of the columns by clicking on the empty tab above the labels, and choose Multivariate > Clustering > Neighbour joining. Here’s a screen cap of me doing just that…



Then, from the tabs on the right, choose Chord as the similarity index and MAR_Iberomaurusian, the most distinct unit in the datasheet, as the root. PAST offers an exceptionally large range of similarity indices and they generally produce similar results, but, in my experience, Chord creates among the most visually pleasing outcomes when dealing with fine scale genetic substructures.



This is the tree you should see after exporting the image via the graph settings tab in PAST, and, if you like, rotating it 90 degrees with an image editing software of your choice. Note the fairly substantial differences between the populations from Northwestern Europe, which are often difficult to tease apart in such analyses.



If you have your own Global25 coordinates you can add them to my PAST-compatible datasheet to see where you cluster in this tree. And, of course, you can design your own PAST-compatible datasheets and trees with any combination of populations and/or individuals from the Global25 text files at the links below. It’s easy; just copy paste the coordinates of your choice into an empty text file, open it with PAST and then save it with the dat extension to create a new PAST datasheet. But make sure never to mix up the scaled and non-scaled coordinates.



Global 25 datasheet (scaled)
Global 25 pop averages (scaled)
Global 25 datasheet
Global 25 pop averages



An important point to keep in mind when running these sorts of analyses is that PAST and other such programs need enough genetic differentiation to latch onto in order to produce meaningful results. Thus, even when studying the relationships between very closely related populations, it’s not just useful to include a root population or individual, but also some near and far related groups to help the analysis algorithm flesh out the key genetic substructures.
To be honest, I don’t really know whether using the Chord index and rooting the tree with MAR_Iberomaurusian is the best way to run a neighbour joining tree analysis of ancient and present-day West Eurasian genetic variation. What do you think? Feel free to let me know in the comments.
See also…
Global25 workshop 1: that classic West Eurasian plot
Global25 workshop 2: intra-European variation
Global25 workshop 3: genes vs geography in Northern Europe
Genetic ancestry online store (to be updated regularly)

Source


Tyrebagger Prehistoric Recumbent Stone Circle, Dyce, Aberdeenshire, 7.7.19.

Tyrebagger Prehistoric Recumbent Stone Circle, Dyce, Aberdeenshire, 7.7.19.












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Culsh Prehistoric Earth House, Tarland, Aberdeenshire, 6.7.19.

Culsh Prehistoric Earth House, Tarland, Aberdeenshire, 6.7.19.










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