среда, 29 августа 2018 г.

Long-sought decay of Higgs boson observed


CERN – European Organization for Nuclear Research logo.


29 Aug 2018



Image above: An ATLAS candidate event for the Higgs boson (H) decaying to two bottom quarks (b), in association with a W boson decaying to a muon (μ) and a neutrino (ν). (Image: ATLAS/CERN).


Six years after its discovery, the Higgs boson has at last been observed decaying to fundamental particles known as bottom quarks. The finding, presented today at CERN by the ATLAS and CMS collaborations at the Large Hadron Collider (LHC), is consistent with the hypothesis that the all-pervading quantum field behind the Higgs boson also gives mass to the bottom quark. Both teams have submitted their results for publication today.


The Standard Model of particle physics predicts that about 60% of the time a Higgs boson will decay to a pair of bottom quarks, the second-heaviest of the six flavours of quarks. Testing this prediction is crucial because the result would either lend support to the Standard Model – which is built upon the idea that the Higgs field endows quarks and other fundamental particles with mass – or rock its foundations and point to new physics.


Spotting this common Higgs-boson decay channel is anything but easy, as the six-year period since the discovery of the boson has shown. The reason for the difficulty is that there are many other ways of producing bottom quarks in proton–proton collisions. This makes it hard to isolate the Higgs-boson decay signal from the background “noise” associated with such processes. By contrast, the less-common Higgs-boson decay channels that were observed at the time of discovery of the particle, such as the decay to a pair of photons, are much easier to extract from the background.


To extract the signal, the ATLAS and CMS collaborations each combined data from the first and second runs of the LHC, which involved collisions at energies of 7, 8 and 13 TeV. They then applied complex analysis methods to the data. The upshot, for both ATLAS and CMS, was the detection of the decay of the Higgs boson to a pair of bottom quarks with a significance that exceeds 5 standard deviations. Furthermore, both teams measured a rate for the decay that is consistent with the Standard Model prediction, within the current precision of the measurement.



Image above: A CMS candidate event for the Higgs boson (H) decaying to two bottom quarks (b), in association with a Z boson decaying to an electron (e-) and an antielectron (e+). (Image: CMS/CERN).


“This observationis a milestone in the exploration of the Higgs boson. It shows that the ATLAS and CMS experiments have achieved deep understanding of their data and a control of backgrounds that surpasses expectations. ATLAS has now observed all couplings of the Higgs boson to the heavy quarks and leptons of the third generation as well as all major production modes,” said Karl Jakobs, spokesperson of the ATLAS collaboration.


“Since the first single-experiment observation of the Higgs boson decay to tau-leptons one year ago, CMS, along with our colleagues in ATLAS, has observed the coupling of the Higgs boson to the heaviest fermions: the tau, the top quark, and now the bottom quark. The superb LHC performance and modern machine-learning techniques allowed us to achieve this result earlier than expected,” said Joel Butler, spokesperson of the CMS collaboration.


With more data, the collaborations will improve the precision of these and other measurements and probe the decay of the Higgs boson into a pair of much-less-massive fermions called muons, always watching for deviations in the data that could point to physics beyond the Standard Model.


“The experiments continue to home in on the Higgs particle, which is often considered a portal to new physics. These beautiful and early achievements also underscore our plans for upgrading the LHC to substantially increase the statistics. The analysis methods have now been shown to reach the precision required for exploration of the full physics landscape, including hopefully new physics that so far hides so subtly,” said CERN Director for Research and Computing Eckhard Elsen.


Note:


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.


The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.


Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.


For more information, see the ATLAS and CMS websites:


ATLAS: https://atlas.cern/updates/press-statement/observation-higgs-boson-decay-pair-bottom-quarks


CMS: http://cms.cern/higgs-observed-decaying-b-quarks-submitted


ATLAS experiment: https://home.cern/about/experiments/atlas


CMS experiment: https://home.cern/about/experiments/cms


Standard Model of particle physics: https://home.cern/about/physics/standard-model


Higgs boson: https://home.cern/topics/higgs-boson


Large Hadron Collider (LHC): https://home.cern/topics/large-hadron-collider


For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/


Images (mentioned), Text, Credits: CERN/Ana Lopes.


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Black Holes are NICER Than You Think!

We’re learning more every day about black holes thanks to one of the instruments aboard the International Space Station! Our Neutron star Interior Composition Explorer (NICER) instrument is keeping an eye on some of the most mysterious cosmic phenomena.


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We’re going to talk about some of the amazing new things NICER is showing us about black holes. But first, let’s talk about black holes — how do they work, and where do they come from? There are two important types of black holes we’ll talk about here: stellar and supermassive. Stellar mass black holes are three to dozens of times as massive as our Sun while supermassive black holes can be billions of times as massive!


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Stellar black holes begin with a bang — literally! They are one of the possible objects left over after a large star dies in a supernova explosion. Scientists think there are as many as a billion stellar mass black holes in our Milky Way galaxy alone!


Supermassive black holes have remained rather mysterious in comparison. Data suggest that supermassive black holes could be created when multiple black holes merge and make a bigger one. Or that these black holes formed during the early stages of galaxy formation, born when massive clouds of gas collapsed billions of years ago. There is very strong evidence that a supermassive black hole lies at the center of all large galaxies, as in our Milky Way.


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Imagine an object 10 times more massive than the Sun squeezed into a sphere approximately the diameter of New York City — or cramming a billion trillion people into a car! These two examples give a sense of how incredibly compact and dense black holes can be.


Because so much stuff is squished into such a relatively small volume, a black hole’s gravity is strong enough that nothing — not even light — can escape from it. But if light can’t escape a dark fate when it encounters a black hole, how can we “see” black holes?


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Scientists can’t observe black holes directly, because light can’t escape to bring us information about what’s going on inside them. Instead, they detect the presence of black holes indirectly — by looking for their effects on the cosmic objects around them. We see stars orbiting something massive but invisible to our telescopes, or even disappearing entirely!


When a star approaches a black hole’s event horizon — the point of no return — it’s torn apart. A technical term for this is “spaghettification” — we’re not kidding! Cosmic objects that go through the process of spaghettification become vertically stretched and horizontally compressed into thin, long shapes like noodles.


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Scientists can also look for accretion disks when searching for black holes. These disks are relatively flat sheets of gas and dust that surround a cosmic object such as a star or black hole. The material in the disk swirls around and around, until it falls into the black hole. And because of the friction created by the constant movement, the material becomes super hot and emits light, including X-rays.  


At last — light! Different wavelengths of light coming from accretion disks are something we can see with our instruments. This reveals important information about black holes, even though we can’t see them directly.


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So what has NICER helped us learn about black holes? One of the objects this instrument has studied during its time aboard the International Space Station is the ever-so-forgettably-named black hole GRS 1915+105, which lies nearly 36,000 light-years — or 200 million billion miles — away, in the direction of the constellation Aquila.


Scientists have found disk winds — fast streams of gas created by heat or pressure — near this black hole. Disk winds are pretty peculiar, and we still have a lot of questions about them. Where do they come from? And do they change the shape of the accretion disk?


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It’s been difficult to answer these questions, but NICER is more sensitive than previous missions designed to return similar science data. Plus NICER often looks at GRS 1915+105 so it can see changes over time.


NICER’s observations of GRS 1915+105 have provided astronomers a prime example of disk wind patterns, allowing scientists to construct models that can help us better understand how accretion disks and their outflows around black holes work.


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NICER has also collected data on a stellar mass black hole with another long name — MAXI J1535-571 (we can call it J1535 for short) — adding to information provided by NuSTAR, Chandra, and MAXI. Even though these are all X-ray detectors, their observations tell us something slightly different about J1535, complementing each other’s data!


This rapidly spinning black hole is part of a binary system, slurping material off its partner, a star. A thin halo of hot gas above the disk illuminates the accretion disk and causes it to glow in X-ray light, which reveals still more information about the shape, temperature, and even the chemical content of the disk. And it turns out that J1535’s disk may be warped!


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Image courtesy of NRAO/AUI and Artist: John Kagaya (Hoshi No Techou)



This isn’t the first time we have seen evidence for a warped disk, but J1535’s disk can help us learn more about stellar black holes in binary systems, such as how they feed off their companions and how the accretion disks around black holes are structured.


NICER primarily studies neutron stars — it’s in the name! These are lighter-weight relatives of black holes that can be formed when stars explode. But NICER is also changing what we know about many types of X-ray sources. Thanks to NICER’s efforts, we are one step closer to a complete picture of black holes. And hey, that’s pretty nice!


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


Geologists discover fullest skull of Wetlugasaurus

This June the staff of the “Geology and Geophysics” Department of Samara Polytech took part in a scientific expedition of the Triassic and Jurassic deposits in the southeast of the Samara region.











Geologists discover fullest skull of Wetlugasaurus
The full skull of the early Triassic period amphibian Wetlugasaurus
[Credit: SamaraPolytech]

One of the findings, made with the participation of the Flagship University scientists, was the skull of a Wetlugasaurus. Then it was just a piece of rock with bones protruding from it and it was difficult to identify anything valuable. In the process of studying the skull, it was prepared from the palate side. The teeth and internal nasal apertures – the choanae – became clearly visible.
“Experts of the leading paleontological institute of the Russian Academy of Sciences (Moscow) conducted a detailed assessment of the findings”, – says the senior lecturer of “Geology and Geophysics” Department Alyona Morova. She added that that they were lucky to find the fullest skull of a Wetlugasaurus in the world. Alyona also said that the news was completely unexpected for the scientists.











Geologists discover fullest skull of Wetlugasaurus
Labyrinthodonts are an extinct subclass of amphibians, the majority of which lived on the Earth in the Paleozoic
and Mesozoic eras (390-150 million years ago). These are the ancestors of all modern mammals,
from mice to elephants [Credit: SamaraPolytech]

The expedition was held with the support and participation of the Paleontological Institute of the Russian Academy of Sciences, Samara Regional Museum of Local History named after P.V. Alabin, Samara Paleontological Society, Togliatti Local History Museum, Institute of Ecology of the Volga Basin of the Russian Academy of Sciences. The expedition was headed by Igor Novikov, a leading researcher at the Paleogerpetology Laboratory of the Paleontological Institute of the Russian Academy of Sciences.


Polytech scientists were also lucky to make another unusual discovery – the remains of the postcranial skeleton (more than 170 fragments) of one specimen of Labyrinthodont. In addition, they collected zoological materials of modern mammals and herbarium specimens of plants, including several rare and Red Book species.


Source: Samara State Technical University [August 27, 2018]



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Three previously unknown ancient primates identified

Biological anthropologists from The University of Texas at Austin have described three new species of fossil primates that were previously unknown to science. All of the new primates were residents of San Diego County at a time when southern California was filled with lush tropical forests.











Three previously unknown ancient primates identified
Kirk’s father and Austin-based artist Randy Kirk produced his own rendering of what the species
might have looked like [Credit: Painting on marble by Randwulph]

Since the 1930s, numerous primate fossils have been uncovered in the sandstones and claystones that make up the Friars Formation in San Diego County. Paleontologist Stephen Walsh and fieldworkers from the San Diego Museum of Natural History (SDNHM) built up a large collection of fossil primates from the San Diego area, but Walsh was unable to describe these specimens before his death in 2007.


A decade later, UT Austin graduate student Amy Atwater and anthropology professor Chris Kirk took up the challenge, describing and naming three previously unknown omomyoid primates that lived 42 million to 46 million years ago. The researchers named these new species Ekwiiyemakius walshi, Gunnelltarsius randalli and Brontomomys cerutti.


These findings double the number of known primate genera represented in the Friars Formation and increase the total number of known omomyine primates of that period from 15 to 18.


“The addition of these primates provides for a better understanding of primate richness in the middle Eocene,” said Atwater, who is now the paleontology collection manager at the Museum of the Rockies in Bozeman, Montana. “Previous research in the Rocky Mountain basins suggested the primate richness declined during this time period, but we argue that primate richness increased concurrently in other locations.”


Studying the teeth, researchers concluded the three new genera, which represent the bulk of the undescribed Friars Formation omomyoid sample at SDNHM, range in size from 113 to 796 grams and are most likely related to a group of extinct species comprising the primate subfamily Omomyinae.


“Teeth can tell us a lot about evolutionary history and give us a good handle on the size and diet of an extinct primate,” Kirk said. “Enamel is the hardest tissue in the body. And as a result, teeth are more likely to be preserved in the fossil record.”


Ekwiiyemakius walshi, the smallest of the three new species, was estimated to weigh between 113 and 125 grams — comparable in size to some modern bushbabies. It was named for Walsh, who collected and prepared many of the specimens, and also derives from the Native American Kumeyaay tribe’s place name, Ekwiiyemak — meaning “behind the clouds” — for the location of the headwaters of the San Diego and Sweetwater Rivers.


Gunnelltarsius randalli was named for Gregg Gunnell, the researchers’ late colleague and expert on Eocene mammals, and for SDNHM fossil collections manager Kesler Randall. It was estimated to weigh between 275 and 303 grams, about the size of today’s fat-tailed dwarf lemur.


Brontomomys cerutti was large compared with most other omomyoids and was estimated to weigh between 719 and 796 grams — about the size of a living sportive lemur. Due to its large size, its name derives from the Greek word bront, or “thunder,” as well as for Richard Cerutti, the retired SDNHM paleontologist responsible for collecting many of the Brontomomys specimens.


Atwater and Kirk’s descriptions were published in the Journal of Human Evolution.


Source: University of Texas at Austin [August 28, 2018]



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Getting to the roots of our ancient cousin’s diet

Food needs to be broken down in the mouth before it can be swallowed and digested further. How this is being done depends on many factors, such as the mechanical properties of the foods and the morphology of the masticatory apparatus. Palaeoanthropologists spend a great deal of their time reconstructing the diets of our ancestors, as diet holds the key to understanding our evolutionary history. For example, a high-quality diet (and meat-eating) likely facilitated the evolution of our large brains, whilst the lack of a nutrient-rich diet probably underlies the extinction of some other species (e.g., P. boisei). The diet of South African hominins has remained particularly controversial however.











Getting to the roots of our ancient cousin's diet
Paranthropus robustus fossil from South Africa SK 46 (discovered 1936, estimated age 1.9-1.5 million years)
and the virtually reconstructed first upper molar used in the analyses [Credit: Kornelius Kupczik,
Max Planck Institute for Evolutionary Anthropology]

Using non-invasive high-resolution computed tomography technology and shape analysis the authors deduced the main direction of loading during mastication (chewing) from the way the tooth roots are oriented within the jaw. By comparing the virtual reconstructions of almost 30 hominin first molars from South and East Africa they found that Australopithecus africanus had much wider splayed roots than both Paranthropus robustus and the East African Paranthropus boisei. “This is indicative of increased laterally-directed chewing loads in Australopithecus africanus, while the two Paranthropus species experienced rather vertical loads”, says Kornelius Kupczik of the Max Planck Institute for Evolutionary Anthropology.
Paranthropus robustus, unlike any of the other species analysed in this study, exhibits an unusual orientation, i.e. “twist”, of the tooth roots, which suggests a slight rotational and back-and-forth movement of the mandible during chewing. Other morphological traits of the P. robustus skull support this interpretation. For example, the structure of the enamel also points towards a complex, multidirectional loading, whilst their unusual microwear pattern can conceivably also be reconciled with a different jaw movement rather than by mastication of novel food sources. Evidently, it is not only what hominins ate and how hard they bit that determines its skull morphology, but also the way in which the jaws are being brought together during chewing.
The new study demonstrates that the orientation of tooth roots within the jaw has much to offer for an understanding of the dietary ecology of our ancestors and extinct cousins. “Perhaps palaeoanthropologists have not always been asking the right questions of the fossil record: rather than focusing on what our extinct cousins ate, we should equally pay attention to how they masticated their foods”, concludes Gabriele Macho of the University of Oxford.


Molar root variation in hominins is therefore telling us more than previously thought. “For me as an anatomist and a dentist, understanding how the jaws of our fossil ancestors worked is very revealing as we can eventually apply such findings to the modern human dentition to better understand pathologies such as malocclusions”, adds Viviana Toro-Ibacache from the University of Chile and one of the co-authors of the study.


The findings are published in Royal Society Open Science.


Source: Max Planck Society [August 28, 2018]



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Ancient aqueducts unearthed as Fayd fort reveals its secrets

Saudi archaeologists have discovered underground aqueducts dating back to early Islamic period. They were found during an excavation in the historic city of Fayd, in Hail, along with bakery ovens, wash basins and a large number of architectural sites.











Ancient aqueducts unearthed as Fayd fort reveals its secrets
Habitation area outside the walls of Fayd Fortress [Credit: Florent Egal]

“The archaeologists, who work under the supervision of the Saudi Commission for Tourism and National Heritage (SCTH), found traces of the underground aqueducts in the archaeological city in Hail,” Majed Alshadeed, a SCTH spokesman, told Arab News on Monday.


The breakthrough discoveries were made outside the fort in Hail, with a second site uncovered in the area between the two walls of the southern side of the fort. A third site was found at Al-Qalqah citadel.


The sites included an ancient mosque dating back to the early Islamic era, in addition to architectural units with several rooms, and architectural details buried between the exterior and interior walls of the fort.


The archaeological action plan included detecting, preparing and cleaning old wells in the traditional city. The wells are connected to the underground aqueducts, Alshadeed said.











Ancient aqueducts unearthed as Fayd fort reveals its secrets
Mosque dating back to the early Islamic era [Credit: Arab News]

A service site for the ancient fort was also uncovered, with bakery ovens and wash basins found in channels that pass through the last underground square. Pottery utensils, and glass, stone and metal pieces were also retrieved.
The city of Fayd is a major archaeological and historical site, located 120 kilometers east of the city of Hail. It is the third city of the old pilgrimage route “Darb Zubaidah” — after Kufa and Basra — and the largest station on the pilgrimage route used by millions of pilgrims for their once-in-a-lifetime Hajj journey to the holy city of Makkah.


Foundations located in the northern part of the fort were built in regular forms using volcanic stones commonly found in the city. Some architectural forms and objects such as basins were also carved from volcanic rock.


The presence of iron residues showed the objects may have been in the manufacture of glass and iron.


Author: Rashid Hassan | Source: Arab News [August 28, 2018]



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Ancient marble statue found in Crimea

A marble statue of a partially draped male torso, said to date to the Hellenistic period, has been found during the course of excavations at the ancient fortifications Myrmekion, an ancient Greek colony in the Crimea.











Ancient marble statue found in Crimea
Credit: Alexander Butyagin

The statue, possibly depicting Asklepios, the Greek god of medicine and patron of physicians, was found in a destruction layer of a villa dating to the first century AD.











Ancient marble statue found in Crimea
Credit: Alexander Butyagin

The colony of Myrmekion was founded by Ionian settlers in the first half of the 6th century BC, in the eastern part of what is today the city Kerch.


Source: Russia News Today [August 28, 2018]



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Archaeologists dig Native American fort found in Connecticut

A 1600s Native American fort uncovered as part of a rail bridge replacement project is shining some light on a tribe’s first dealings with Europeans, archeologists said on Tuesday during a tour of the site.











Archaeologists dig Native American fort found in Connecticut
Archaeologist Ross Harper holds a notched projectile, estimated to be 3,000 years old, found
at the site of a Native American fort in Norwalk, Conn. [Credit: AP/Dave Collins]

The find on a small sliver of land next to railroad tracks that carry Amtrak and Metro-North commuter trains is considered one of the most important discoveries in the Northeast for Native American history.
Not only did experts recently find the remains of the 17th century fort, they discovered some artifacts including arrow and spear tips that date back an estimated 3,000 years, indicating Native Americans were active at the site for generations. No evidence of human remains has been found.


“It’s one of the earliest historic period sites that has been found so far,” said archaeologist Ross Harper. “And it’s very rich in artifacts including Native American pottery and stone tools, as well as trade goods such as glass beads, wampum, hatchets and knives. It’s definitely one of the more important sites, not just for the area but New England in general.”











Archaeologists dig Native American fort found in Connecticut
Emma Wink, right, and Stephanie Scialo, part of an archaeological team, work at the site
of a 1600s Native American fort in Norwalk, Conn. [Credit: AP/Dave Collins]

Harper said he believes the fort had wooden walls because what appeared to be post holes were found where vertical wood pieces were placed.
He said it appears the Norwalk Indians, a tribe that historians know little about, had a fort at the site from about 1615 to 1640 and used it to trade goods with early Dutch settlers. The site is on a small sliver of land next to railroad tracks that carry Amtrak and Metro-North commuter trains. A 19th century history of Norwalk mentions an old Native American fort, and a road near the site is still named Fort Point Street.


The site was found during preliminary archaeological surveys ordered as part of the state’s upcoming replacement of the 122-year-old Walk Bridge, which spans the Norwalk River and swings open to allow boats to pass. The bridge has gotten stuck in the open position several times and caused massive rail service delays. Construction is set to begin next year.











Archaeologists dig Native American fort found in Connecticut
Emma Wink, part of an archaeological team, digs at the site of a 1600s Native American fort
in Norwalk, Conn. [Credit: AP/Dave Collins]

Harper works for Archaeological & Historical Services Inc., a Storrs, Connecticut-based firm that is painstakingly removing artifacts from the site and taking them back to its offices for cleaning and further study. Some of the artifacts may be headed to museums. The firm will write a lengthy report on the artifacts and its findings.


The firm, which plans to completely remove all artifacts from the site by the fall, has been working in consultation with the Mashantucket Pequots and Mohegans — the two federally recognized tribes in the state. There is no known opposition to the removal of the artifacts.


The two tribes issued a joint statement on the project this week.


“Any time a Native American site or artifacts are found, the utmost sensitivity should be used,” the statement said. “While the Walk Bridge construction site in Norwalk may or may not have direct ties to the Mohegan or Mashantucket Pequot tribes … we take the matter seriously. In fact, Tribal Preservation Officers from both tribes have actively been working with people on the ground there for over a year to offer their expertise.”











Archaeologists dig Native American fort found in Connecticut
The site of a 1600s Native American fort in Norwalk, Conn. [Credit: AP/Dave Collins]

The site is one of only about a half-dozen in the Northeast known to have contained evidence of Native Americans’ first encounters with Europeans, and most of the sites have been destroyed or removed during development of the lands, Harper said.


The rare find is what drew about 20 archaeologists from the region to Tuesday’s tour in oppressively hot weather.


“For me, it’s like a gold mine,” said Kevin McBride, an anthropology professor at the University of Connecticut and research director at the Mashantucket Pequot Museum. “I think the reason the site is so important is that there’s a lot of material here. It’s definitely one of the most important sites we’ve found in a long time.”


McBride said items found at the site provide some insight into Native Americans’ first interactions with Europeans and show how they incorporated European products such as iron tools and knives into their culture.


Author: Dave Collins | Source: The Associated Press [August 29, 2018]



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Helpful Hippo Living organisms need a constant supply of new…


Helpful Hippo


Living organisms need a constant supply of new cells in order to grow to the right size, repair wounds, and replace old or damaged tissue. But too much cell proliferation can quickly lead to cancer. One of the most important genes involved in controlling size and cell growth is called Hippo, which gets its name because fruit flies lacking the gene become abnormally large and wrinkly, like little hippopotamuses. Hippo is found in a wide range of animals, from humans and other mammals down to tiny flatworms, and faults in the gene have been implicated in cancer. This bulging mass is a tumour on the side of a flatworm’s body, caused by switching off Hippo in a small group of cells. It proves that Hippo plays a vital role in controlling cell growth in the worms, suggesting what it might be doing to protect against cancer in more complex animals.


Written by Kat Arney



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Coed Aber Iron Age Roundhouse, nr Abergwyngregn, North Wales,…











Coed Aber Iron Age Roundhouse, nr Abergwyngregn, North Wales, 28.8.18.


This lovely Iron Age roundhouse is built around a Bronze Age standing stone next to the stunning Aber Falls. With the wooded slopes of a valley, winding river and view to the sea, this is very ‘fairy tale picturesque’. It’s easy to see why our prehistoric ancestors might have chosen to live at this location!


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NASA’s InSight Has a Thermometer for Mars


NASA – InSight Mission logo.


August 29, 2018


Ambitious climbers, forget Mt. Everest. Dream about Mars.



Animation above: NASA’s InSight Mars lander will carry a unique instrument capable of measuring heat flowing out of the planet. That could shed light on how Mars’ massive mountains — which eclipse Mt. Everest here on Earth — first formed.Animation Credits: NASA/JPL-Caltech.


The Red Planet has some of the tallest mountains in the solar system. They include Olympus Mons, a volcano nearly three times the height of Everest. It borders a region called the Tharsis plateau, where three equally awe-inspiring volcanoes dominate the landscape.


But what geologic processes created these features on the Martian surface? Scientists have long wondered — and may soon know more.


NASA and DLR (German Aerospace Center) plan to take the planet’s temperature for the first time ever, measuring how heat flows out of the planet and drives this inspiring geology. Detecting this escaping heat will be a crucial part of a mission called InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport), managed by NASA’s Jet Propulsion Laboratory in Pasadena, California.


InSight will be the first mission to study Mars’ deep interior, using its Heat Flow and Physical Properties Package (HP3) instrument to measure heat as it is conducted from the interior to the planet’s surface. This energy was in part captured when Mars formed more than 4 billion years ago, preserving a record of its creation. That energy is also due to the decay of radioactive elements in the rocky interior.


The way heat moves through a planet’s mantle and crust determines what surface features it will have, said Sue Smrekar of JPL, the mission’s deputy principal investigator and the deputy lead for HP3.


“Most of the planet’s geology is a result of heat,” Smrekar said. “Volcanic eruptions in the ancient past were driven by the flow of this heat, pushing up and constructing the towering mountains Mars is famous for.”



Mars in a Minute: How Did Mars Get Such Enormous Mountains?

A mole for Mars


While scientists have modeled the interior structure of Mars, InSight will provide the first opportunity to find ground truth — by literally looking below the ground.


HP3, built and operated by DLR, will be placed on the Martian surface after InSight lands on Nov. 26, 2018. A probe called a mole will pummel the ground, burying itself and dragging a tether behind it. Temperature sensors embedded in this tether will measure the natural internal heat of Mars.


That’s no easy task. The mole has to burrow deep enough to escape the wide temperature swings of the Martian surface. Even the spacecraft’s own “body heat” could affect HP3’s super-sensitive readings.


“If the mole gets stuck higher up than expected, we can still measure the temperature variation,” said HP3 investigation lead Tilman Spohn of DLR. “Our data will have more noise, but we can subtract out daily and seasonal weather variations by comparing it with ground-temperature measurements.”


In addition to burrowing, the mole will give off heat pulses. Scientists will study how quickly the mole warms the surrounding rock, allowing them to figure out how well heat is conducted by the rock grains at the landing site. Densely packed grains conduct heat better — an important piece of the equation for determining Mars’ internal energy.


Cooking up a new planet


For an example of planetary heat flow, imagine a pot of water on a stove.


As water heats, it expands, becomes less dense, and rises. The cooler, denser water sinks to the bottom, where it heats up. This cycling of cool to hot is called convection. The same thing happens inside a planet, churning rock over millions of years.


Just as expanding bubbles can push off a pot lid, volcanoes are lids being blown off the top of a world. They shape a planet’s surface in the process. Most of the atmosphere on rocky planets forms as volcanoes expel gas from deep below. Some of Mars’ biggest dry river beds are believed to have formed when the Tharsis volcanoes spewed gas into the atmosphere. That gas contained water vapor, which cooled into liquid and may have formed the channels surrounding Tharsis.


The smaller the planet, the faster it loses its original heat. Since Mars is only one-third the size of Earth, most of its heat was lost early in its history. Most Martian geologic activity, including volcanism, occurred in the planet’s first billion years.



Mars InSight, studying Mars interior. Image Credits: NASA/JPL

“We want to know what drove the early volcanism and climate change on Mars,” Spohn said. “How much heat did Mars start with? How much was left to drive its volcanism?”


NASA’s orbiters have given scientists a “macro” view of the planet, allowing them to study Martian geology from above. HP3will offer a first look at the inside of Mars.


“Planets are kind of like an engine, driven by heat that moves their internal parts around,” Smrekar said. “With HP3, we’ll be lifting the hood on Mars’ engine for the first time.”


What scientists learn during the InSight mission won’t just apply to Mars. It will teach them how all rocky planets formed — including Earth, its Moon and even planets in other solar systems.


JPL, a division of Caltech in Pasadena, California, manages InSight for NASA’s Science Mission Directorate in Washington. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. The InSight spacecraft, including cruise stage and lander, was built and tested by Lockheed Martin Space in Denver.


Heat Flow and Physical Properties Package (HP3): https://mars.nasa.gov/insight/mission/instruments/hp3/


More information about InSight is at: https://mars.nasa.gov/insight


Image (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Andrew Good.


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Stars v. Dust in the Carina Nebula


ESO – European Southern Observatory logo.


29 August 2018


VISTA gazes into one of the largest nebulae in the Milky Way in infrared



The Carina Nebula in infrared light

The Carina Nebula, one of the largest and brightest nebulae in the night sky, has been beautifully imaged by ESO’s VISTA telescope at the Paranal Observatory in Chile. By observing in infrared light, VISTA has peered through the hot gas and dark dust enshrouding the nebula to show us myriad stars, both newborn and in their death throes.



A wider view of the Carina Nebula

About 7500 light-years away, in the constellation of Carina, lies a nebula within which stars form and perish side-by-side. Shaped by these dramatic events, the Carina Nebula is a dynamic, evolving cloud of thinly spread interstellar gas and dust.



Digitized Sky Survey image of Eta Carinae Nebula

The massive stars in the interior of this cosmic bubble emit intense radiation that causes the surrounding gas to glow. By contrast, other regions of the nebula contain dark pillars of dust cloaking newborn stars. There’s a battle raging between stars and dust in the Carina Nebula, and the newly formed stars are winning — they produce high-energy radiation and stellar winds which evaporate and disperse the dusty stellar nurseries in which they formed.



The Carina Nebula in the constellation of Carina

Spanning over 300 light-years, the Carina Nebula is one of the Milky Way’s largest star-forming regions and is easily visible to the unaided eye under dark skies. Unfortunately for those of us living in the north, it lies 60 degrees below the celestial equator, so is visible only from the Southern Hemisphere.



3D view of the Carina Nebula

Within this intriguing nebula, Eta Carinae takes pride of place as the most peculiar star system. This stellar behemoth — a curious form of stellar binary— is the most energetic star system in this region and was one of the brightest objects in the sky in the 1830s. It has since faded dramatically and is reaching the end of its life, but remains one of the most massive and luminous star systems in the Milky Way.



Zoom into the Carina Nebula

Eta Carinae can be seen in this image as part of the bright patch of light just above the point of the “V” shape made by the dust clouds. Directly to the right of Eta Carinae is the relatively small Keyhole Nebula — a small, dense cloud of cold molecules and gas within the Carina Nebula — which hosts several massive stars, and whose appearance has also changed drastically over recent centuries.



Pan across the Carina Nebula

The Carina Nebula was discovered from the Cape of Good Hope by Nicolas Louis de Lacaille in the 1750s and a huge number of images have been taken of it since then. But VISTA — the Visible and Infrared Survey Telescope for Astronomy — adds an unprecedentedly detailed view over a large area; its infrared vision is perfect for revealing the agglomerations of young stars hidden within the dusty material snaking through the Carina Nebula. In 2014, VISTA was used to pinpoint nearly five million individual sources of infrared light within this nebula, revealing the vast extent of this stellar breeding ground. VISTA is the world’s largest infrared telescope dedicated to surveys and its large mirror, wide field of view and exquisitely sensitive detectors enable astronomers [1] to unveil a completely new view of the southern sky.


Notes:


[1] The Principal Investigator of the observing proposal which led to this spectacular image was Jim Emerson (School of Physics & Astronomy, Queen Mary University of London, UK). His collaborators were Simon Hodgkin and Mike Irwin (Cambridge Astronomical Survey Unit, Cambridge University, UK). The data reduction was performed by Mike Irwin and Jim Lewis (Cambridge Astronomical Survey Unit, Cambridge University, UK).


More information:


ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.


Links:


ESOcast 175 Light: Stars and Dust in the Carina Nebula: https://www.eso.org/public/videos/eso1828a/


More information about VISTA: http://www.eso.org/public/teles-instr/paranal-observatory/surveytelescopes/vista/


Photos of VISTA: https://www.eso.org/public/images/archive/category/surveytelescopes/


More ESO images of the Carina Nebula: https://www.eso.org/public/images/?search=Carina+Nebula


Images, Text, Credits: ESO/Garching bei München/Calum Turner/School of Physics & Astronomy, Queen Mary University of London/J. Emerson/M. Irwin/J. Lewis/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/IAU and Sky & Telescope/Videos: ESO, M. Kornmesser/DSS/Risinger/Music: Johan B. Monell.


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2018 August 29 Nearby Cepheid Variable RS Pup Image Credit:…


2018 August 29


Nearby Cepheid Variable RS Pup
Image Credit: NASA, ESA, Hubble Heritage Team; Acknowledgement: Howard Bond (STScI & Penn State U.)


Explanation: In the center is one of the most important stars on the sky. This is partly because, by coincidence, it is surrounded by a dazzling reflection nebula. Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid type variable star, a class of stars whose brightness is used to estimate distances to nearby galaxies as one of the first steps in establishing the cosmic distance scale. As RS Pup pulsates over a period of about 40 days, its regular changes in brightness are also seen along the nebula delayed in time, effectively a light echo. Using measurements of the time delay and angular size of the nebula, the known speed of light allows astronomers to geometrically determine the distance to RS Pup to be 6,500 light-years, with a remarkably small error of plus or minus 90 light-years. An impressive achievement for stellar astronomy, the echo-measured distance also more accurately establishes the true brightness of RS Pup, and by extension other Cepheid stars, improving the knowledge of distances to galaxies beyond the Milky Way. The featured image was taken by the Hubble Space Telescope.


∞ Source: apod.nasa.gov/apod/ap180829.html


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