вторник, 27 ноября 2018 г.

InSight Is Catching Rays on Mars


NASA – InSight Mission logo.


Nov. 27, 2018



Image above: The Instrument Deployment Camera (IDC), located on the robotic arm of NASA’s InSight lander, took this picture of the Martian surface on Nov. 26, 2018, the same day the spacecraft touched down on the Red Planet. The camera’s transparent dust cover is still on in this image, to prevent particulates kicked up during landing from settling on the camera’s lens. This image was relayed from InSight to Earth via NASA’s Odyssey spacecraft, currently orbiting Mars. Image Credits: NASA/JPL-Caltech.


NASA’s InSight has sent signals to Earth indicating that its solar panels are open and collecting sunlight on the Martian surface. NASA’s Mars Odyssey orbiter relayed the signals, which were received on Earth at about 5:30 p.m. PST (8:30 p.m. EST). Solar array deployment ensures the spacecraft can recharge its batteries each day. Odyssey also relayed a pair of images showing InSight’s landing site.


“The InSight team can rest a little easier tonight now that we know the spacecraft solar arrays are deployed and recharging the batteries,” said Tom Hoffman, InSight’s project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, which leads the mission. “It’s been a long day for the team. But tomorrow begins an exciting new chapter for InSight: surface operations and the beginning of the instrument deployment phase.”


InSight’s twin solar arrays are each 7 feet (2.2 meters) wide; when they’re open, the entire lander is about the size of a big 1960s convertible. Mars has weaker sunlight than Earth because it’s much farther away from the Sun. But the lander doesn’t need much to operate: The panels provide 600 to 700 watts on a clear day, enough to power a household blender and plenty to keep its instruments conducting science on the Red Planet. Even when dust covers the panels — what is likely to be a common occurrence on Mars — they should be able to provide at least 200 to 300 watts.



Animation Credits: NASA/JPL-Caltech

The panels are modeled on those used with NASA’s Phoenix Mars Lander, though InSight’s are slightly larger in order to provide more power output and to increase their structural strength. These changes were necessary to support operations for one full Mars year (two Earth years).


In the coming days, the mission team will unstow InSight’s robotic arm and use the attached camera to snap photos of the ground so that engineers can decide where to place the spacecraft’s scientific instruments. It will take two to three months before those instruments are fully deployed and sending back data.


In the meantime, InSight will use its weather sensors and magnetometer to take readings from its landing site at Elysium Planitia — its new home on Mars.


About InSight


JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.


A number of European partners, including France’s Centre National d’Études Spatiales (CNES), the Institut de Physique du Globe de Paris (IPGP) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and IPGP provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.


Related articles:


NASA InSight Lander Arrives on Martian Surface to Learn What Lies Beneath:
https://orbiterchspacenews.blogspot.com/2018/11/nasa-insight-lander-arrives-on-martian.html


NASA’s InSight Spacecraft Has Touched Down on Mars:
https://orbiterchspacenews.blogspot.com/2018/11/nasas-insight-spacecraft-has-touched.html


For more information about InSight, visit: https://mars.nasa.gov/insight/


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


Greetings, Orbiter.chArchive link


Prehistoric Inspired 19th century Wedgewood Pottery, Devizes Museum, Wiltshire,...











Prehistoric Inspired 19th century Wedgewood Pottery, Devizes Museum, Wiltshire, 17.11.18.


As prehistoric excavations in Britain reached their height in the nineteenth century, Wedgewood produced a series of ceramics to adorn fashionable houses and estates.


Source link


Human ancestors not to blame for ancient mammal extinctions in…


Human ancestors not to blame for ancient mammal extinctions in Africa http://www.geologypage.com/2018/11/human-ancestors-not-to-blame-for-ancient-mammal-extinctions-in-africa.html


Evolution: South Africa’s hominin record is a fair-weather…


Evolution: South Africa’s hominin record is a fair-weather friend http://www.geologypage.com/2018/11/evolution-south-africas-hominin-record-is-a-fair-weather-friend.html


Detective mission to characterise and trace the history of a new…


Detective mission to characterise and trace the history of a new African meteorite http://www.geologypage.com/2018/11/detective-mission-to-characterise-and-trace-the-history-of-a-new-african-meteorite.html


A large volcanic eruption shook Deception Island 3,980 years ago…


A large volcanic eruption shook Deception Island 3,980 years ago http://www.geologypage.com/2018/11/a-large-volcanic-eruption-shook-deception-island-3980-years-ago.html


2018 November 27 InSight’s First Image from Mars Image…


2018 November 27


InSight’s First Image from Mars
Image Credit: NASA/JPL-Caltech


Explanation: Welcome to Mars, NASA Insight. Yesterday NASA’s robotic spacecraft InSight made a dramatic landing on Mars after a six-month trek across the inner Solar System. Needing to brake from 20,000 km per hour to zero in about seven minutes, Insight decelerated by as much as 8 g’s and heated up to 1500 degrees Celsius as it deployed a heat shield, a parachute, and at the end, rockets. The featured image was the first taken by InSight on Mars, and welcome proof that the spacecraft had shed enough speed to land softly and function on the red planet. During its final descent, InSight’s rockets kicked up dust which can be seen stuck to the lens cap of the Instrument Context Camera. Past the spotty dirt, parts of the lander that are visible include cover bolts at the bottom and a lander footpad on the lower right. Small rocks are visible across the rusty red soil, while the arc across the top of the image is the Martian horizon dividing land and sky. Over the next few weeks InSight will deploy several scientific instruments, including a rumble-detecting seismometer. These instruments are expected to give humanity unprecedented data involving the interior of Mars, a region thought to harbor formation clues not only about Mars, but Earth.


∞ Source: apod.nasa.gov/apod/ap181127.html


Baryte Stalactite | #Geology #GeologyPage #Mineral Locality:…


Baryte Stalactite | #Geology #GeologyPage #Mineral


Locality: Hollandtwine Mine section, Dirtlow Rake, Castleton, Derbyshire, England, UK, Europe


Dimensions: 9.9 × 9.8 × 3.4 cm


Photo Copyright © Crystal Classics


Geology Page

www.geologypage.com

https://www.instagram.com/p/BqrGD48lj4h/?utm_source=ig_tumblr_share&igshid=34wn564l6obv


Jashak salt dome, Zagros Mountains, in southwestern Iran |…


Jashak salt dome, Zagros Mountains, in southwestern Iran | #Geology #GeologyPage #Mountain #Iran


Dashti salt dome or jashak salt dome in the Zagros Mountains, in southwestern Iran. this salt dome there is between Dashti County and Dayyer County in Bushehr Province in Iran. This salt dome in Jashak Mountains near the Gankhak-e Raisi in Kaki and Dashti County. This dome is among the most beautiful and typical of Iran salt domes


Geology Page

www.geologypage.com

https://www.instagram.com/p/BqrGJB3FCxI/?utm_source=ig_tumblr_share&igshid=a11hnny6sxsx


Calcite on Fluorite | #Geology #GeologyPage #Mineral Locality:…


Calcite on Fluorite | #Geology #GeologyPage #Mineral


Locality: Lee’s Shaft, Millclose mine in Derbyshire, England


Dimensions: 8.7 × 6.2 × 3.4 cm


Photo Copyright © Crystal Classics


Geology Page

www.geologypage.com

https://www.instagram.com/p/BqrGPH6FvlD/?utm_source=ig_tumblr_share&igshid=t73el4tl1otj


HiPOD (26 November 2018): Branched Ridges in Northeast Arabia…



HiPOD (26 November 2018): Branched Ridges in Northeast Arabia Terra


   – Could these features be inverted stream channels and a depositional (alluvial) fan? (Alt: 296 km. Black and white is less than 5 km across; enhanced color is less than 1 km.)


NASA/JPL/University of Arizona


The Changing Climate of MarsA story of changes in the climate of…


The Changing Climate of Mars


A story of changes in the climate of Mars is told by icy deposits. Remnants of a formerly extensive deposit composed of dry ice layered together with dust and water ice form what is known as the south polar residual cap.


This deposit is shrinking over time as the frozen carbon dioxide turns to vapor. Rounded valleys that give the deposit an appearance resembling Swiss cheese are enlarging over time, exposing an older surface below that is likely made up of water ice.


Read more here.


NASA/JPL/University of Arizona


Tombs of the Eastern Han Dynasty discovered in China’s Sichuan

Four brick tombs from the Eastern Han Dynasty (25-220) were discovered in Chenghua District of Chengdu, capital of southwest China’s Sichuan Province, in October this year, according to the Chengdu cultural relics and archaeology research institute.











Tombs of the Eastern Han Dynasty discovered in China's Sichuan
Credit: Xinhua/Liu Kun

Tang Bin, the on-site archaeological excavation leader, said the Chengdu Cultural Relics and Archaeology Institute began the rescue excavation of the Han tombs on October 13 after they were discovered during the construction of a municipal road on the east bank of the Shahe River.
Archaeologists working at the site reported that the tombs are all facing west, in a uniform parallel arrangement. All four tombs had been plundered in the past.


Tombs of the Eastern Han Dynasty discovered in China's Sichuan

Tombs of the Eastern Han Dynasty discovered in China's Sichuan










Tombs of the Eastern Han Dynasty discovered in China's Sichuan
Credit: Xinhua/Liu Kun

Only one (Tomb M3) of the four tombs was relatively well preserved. It has a total length of about 14 metres and is made of rectangular solid patterned bricks.
Tang Bin, said the items found in Tomb M3 include earthenware, ceramic figurines and iron swords, as well as an earthen pedestal of a ‘money tree’.


Tombs of the Eastern Han Dynasty discovered in China's Sichuan

Tombs of the Eastern Han Dynasty discovered in China's Sichuan










Tombs of the Eastern Han Dynasty discovered in China's Sichuan
Credit: Xinhua/Liu Kun

A stack of bronze coins were all that were left of the money tree, whose main body had been stolen together with the remains of the tomb owners.
“The discovery provides valuable material for the study of Eastern Han tombs as well as the funeral rituals and customs of the period,” Tang said.


Source: Xinhua [November 21, 2018]



TANN



Archive


Corals and their microbiomes evolved together, new research shows

Corals and the microbes they host evolved together, new research by Oregon State University shows. The findings, published in Nature Communications, add fresh insight to the fight to save the Earth’s embattled coral reefs, the planet’s largest and most significant structures of biological origin.











Corals and their microbiomes evolved together, new research shows
Corals and the microbes they host evolved together, new research shows, adding fresh insight to the fight
to save the Earth’s embattled coral reefs [Credit: Zack Gold and Lupita Ruiz-Jones]

Funded by the National Science Foundation, the study involved hundreds of samples of scleractinian corals – also known as stony corals – which since their first appearance 425 million years ago have branched into more than 1,500 species.


Many of those are major builders of coral reefs, which are found in less than 1 percent of the ocean but are home to nearly one-quarter of all known marine species. Reefs also help regulate the sea’s carbon dioxide levels and are a crucial hunting ground that scientists use in the search for new medicines.


“Many corals have gone extinct during industrialization and many others are threatened with extinction,” said study co-author and OSU microbiologist Rebecca Vega Thurber, who is featured in the 2018 Oregon State University-produced documentary “Saving Atlantis.” “If we see patterns of evolution between microbiomes and corals, that gives us an idea of which microbes to target – to learn what they do, how they help corals resist climate change, and how they help to buffer against nutrient pollution. We can look in more depth at the microbes and understand how they help or hurt their hosts.”


Modern corals are home to a complex composition of dinoflagellates, fungi, bacteria and archaea that together make up the coral microbiome. Shifts in microbiome composition are connected to changes in coral health.


“Likely the ancestral corals also harbored complex microbial communities but there’s a lot we don’t know about how these coral-microbe symbioses evolved or the key factors influencing microbial communities in modern corals,” Vega Thurber said. “Certain species of corals have distinct microbiomes, to the point where that occurred at some point in their evolutionary history. Not 400 million years ago, but there are specific groups of microbes that do show very strong evidence of evolving with their hosts more recently.”


Vega Thurber and Ryan McMinds, a Ph.D. student in her lab and co-first author of the paper, were part of an international collaboration that also included Penn State University’s Monica Medina and former Oregon State post-doctoral scholar Jesse Zaneveld, now an assistant professor at the University of Washington-Bothell.


The massive, computationally challenging research project involved taking 600 coral samples from 21 reefs off the coasts of Australia, spanning 17 degrees of latitude.


“On a lot of different scales, the more similar the coral hosts, the more similar the microbial communities are – both the whole community and particular microbes,” McMinds said. “We collected samples from as many kinds of corals as was possible. For every sample set, we looked at the corals’ tissue, skeleton and mucus to see what microbes were there.”


To do that, the researchers sequenced the 16S rRNA gene. The gene is present in every living organism, McMinds explains, but is slightly different. He likened it to a “molecular bar code” of each organism it belongs to.


From there, the scientists could look for patterns between different corals’ microbial communities and determine whether co-evolution of the corals and their microbiomes had taken place.


“We found strong support for coral-microbe ‘phylosymbiosis,’ in which coral microbiome composition and richness is reflected in coral host’s evolutionary history,” Vega Thurber said. “When speciation for modern reef-building coral families began between roughly 25 million and 65 years ago, that was accompanied by large changes in microbiome richness. And changes continued to accumulate during more recent speciation events.”


Coral diversity is too great for assessing the various factors that maintain the microbiome of every single coral species, but these findings provide general rules for microbiome assembly “that inform estimates of the effects of microorganisms in understudied portions of the coral tree.”


“Now we have a framework for analyzing scleractinian coral microbes that can reveal how the corals’ evolutionary history, host traits and local environment interact to shape microbiomes,” Vega Thurber said. “In the coral world, there’s been a longstanding hypothesis that microbes and coral co-evolved, but there hadn’t been a sufficient data set to test that before now.”


It was something of a surprise to researchers to find that the microbial communities of the corals’ calcium carbonate skeletons showed greater microbiome richness compared to the tissue and mucus microbiomes. Also, the skeletal microbiomes displayed the strongest signal of long-term phylosymbiosis – a pattern in which the diversification of a related group of host organisms correlates with changes in dissimilarities among their microbiomes.


“We originally thought corals would show signs of phylosymbiosis throughout their entire phylogenetic history, and the results support that for the skeleton and tissue but not the mucus,” McMinds said. “Despite variability in the chemical composition of mucus between species and significant host-specificity in the mucus microbiome, host specificity was limited to relatively recent divergences.”


He also noted the research found potential significance in “a few groups of microbes no one had thought were important to look at.”


“There are thousands of different species of microbes and not that many that researchers have thought were interesting, and we identified a couple of other microbial targets that might be influencing coral health,” McMinds said. “We don’t know for sure if they are important, but evidence suggests they’re changing along with their hosts, so it’s probably something important they’re doing. They’re not a standard symbiont but it seems they’re something worth looking at more closely.”


Source: Oregon Stage University [November 22, 2018]



TANN



Archive


Gigantic mammal ‘cousin’ discovered

During the Triassic period (252-201 million years ago) mammal-like reptiles called therapsids co-existed with ancestors to dinosaurs, crocodiles, mammals, pterosaurs, turtles, frogs, and lizards. One group of therapsids are the dicynodonts. Researchers at Uppsala University in Sweden, together with colleagues in Poland, have discovered fossils from a new genus of gigantic dicynodont. The new species Lisowicia bojani is described in the journal Science.











Gigantic mammal 'cousin' discovered
During the Triassic period (252-201 million years ago) mammal-like reptiles called therapsids co-existed with ancestors
to dinosaurs, crocodiles, mammals, pterosaurs, turtles, frogs, and lizards. One group of therapsids are the dicynodonts.
 Researchers at Uppsala University in Sweden, together with colleagues in Poland, have discovered fossils
 from a new genus of gigantic dicynodont: Lisowicia bojani [Credit: Tomasz Sulej]

The earth is about 4.5 billion years old and has gone through many geological periods and dramatic change. During the Triassic period, about 252-201 million years ago, all land on Earth came together and formed the massive continent called Pangea. During this time, the first dinosaurs came into being as well as ancestors to crocodiles, mammals, pterosaurs, turtles, frogs, and lizards. Recently, scientists have become interested in another type of animal, therapsids.
Therapsids were “mammal-like” reptiles and are ancestors to the mammals, including humans, found today. One group of therapsids is called dicynodonts. All species of dicynodonts were herbivores (plant eaters) and their sizes ranged from small burrowers to large browsers. Most of them were also toothless. They survived the Permian mass extinction and became the dominant terrestrial herbivores in the Middle and Late Triassic. They were thought to have died out before the dinosaurs became the dominant form of tetrapod on land.


For the first time, researchers in the research programme Evolution and Development at Uppsala University in collaboration with researchers at the Polish Academy of Sciences (Warsaw), have discovered fossils from a new species of dicynodont in the Polish village of Lisowice. The species was named Lisowicia bojani after the village and a German comparative anatomist named Ludwig Heinrich Bojanus who worked in Vilnius and is known for making several important anatomical discoveries.











Gigantic mammal 'cousin' discovered
Artistic reconstruction of Lisowicia bojani, front view
[Credit: Karolina Suchan-Okulska]

The findings show that the Lisowicia was about the size of a modern-day elephant, about 4.5 metres long, 2.6 metres high and weighed approximately 9 tons, which is 40 percent larger than any previously identified dicynodont. Analysis of the limb bones showed that they had a fast growth, much like a mammal or a dinosaur. It lived during the Late Triassic, about 210-205 million years ago, about 10 million years later than previous findings of dicynodonts.
“The discovery of Lisowicia changes our ideas about the latest history of dicynodonts, mammal Triassic relatives. It also raises far more questions about what really make them and dinosaurs so large,” says Dr Tomasz Sulej, Polish Academy of Sciences.


“Dicynodonts were amazingly successful animals in the Middle and Late Triassic. Lisowicia is the youngest dicynodont and the largest non-dinosaurian terrestrial tetrapod from the Triassic. It’s natural to want to know how dicynodonts became so large. Lisowicia is hugely exciting because it blows holes in many of our classic ideas of Triassic ‘mammal-like reptiles’,” says Dr Grzegorz Niedzwiedzki, Uppsala University.











Gigantic mammal 'cousin' discovered
Limb bones of dicynodont, Lisowice locality, Silesia, Poland
[Credit: Grzegorz Niedzwiedzki]

The first findings of fossils from Lisowice in Poland were made in 2005 by Robert Borz?cki and Piotr Menducki. Since then, more than 1,000 bones and bone fragments have been collected from the area, including fossils from Lisowicia. The area is thought to have been a river deposit during the Late Triassic period.
The discovery of Lisowicia provides the first evidence that mammal-like elephant sized dicynodonts were present at the same time as the more well-known long-necked sauropodomorph dinosaurs, contrary to previous belief. Sauropodomorphs include species like the Diplodocus or Brachiosaurus. It fills a gap in the fossil record of dicynodonts and it shows that some anatomical features of limbs thought to characterize large mammals or dinosaurs evolved also in the non-mammalian synapsid. Finally, these findings from Poland are the first substantial finds of dicynodonts from the Late Triassic in Europe.


“The discovery of such an important new species is a once in a lifetime discovery,” says Dr Tomasz Sulej.


Source: Uppsala University [November 22, 2018]



TANN



Archive


Human ancestors not to blame for ancient mammal extinctions in Africa

New research disputes a long-held view that our earliest tool-bearing ancestors contributed to the demise of large mammals in Africa over the last several million years. Instead, the researchers argue that long-term environmental change drove the extinctions, mainly in the form of grassland expansion likely caused by falling atmospheric carbon dioxide (CO2) levels.











Human ancestors not to blame for ancient mammal extinctions in Africa
A fossil tooth of a hippo (Hippopotamus amphibius) (left) and a fossil tooth of a white rhinoceros (Ceratotherium
simum) (right) , two of the few surviving megaherbivores, from the Late Pleistocene of western Kenya (left)
 [Credit: J. Tyler Faith]

Tyler Faith, curator of archaeology at the Natural History Museum of Utah and assistant professor in the Department of Anthropology at the University of Utah, led the study. The research team also includes John Rowan from the University of Massachusetts Amherst, Andrew Du from the University of Chicago, and Paul Koch from the University of California, Santa Cruz.
“Despite decades of literature asserting that early hominins impacted ancient African faunas, there have been few attempts to actually test this scenario or to explore alternatives,” Faith says. “We think our study is a major step towards understanding the depth of anthropogenic impacts on large mammal communities, and provides a convincing counter-argument to these long-held views about our early ancestors.”


To test for ancient hominin impacts, the researchers compiled a seven-million-year record of herbivore extinctions in eastern Africa, focusing on the very largest species, the so-called ‘megaherbivores’ (species over 2,000 lbs.) Though only five megaherbivores exist in Africa today, there was a much greater diversity in the past. For example, three-million-year-old ‘Lucy’ (Australopithecus afarensis) shared her woodland landscape with three giraffes, two rhinos, a hippo, and four elephant-like species at Hadar, Ethiopia.











Human ancestors not to blame for ancient mammal extinctions in Africa
The decline of African megaherbivore diversity (gray curve) over the last seven million years was driven by falling
atmospheric carbon dioxide and the expansion of grasslands, not ancient hominin impacts. The onset of the
megaherbivore decline around 4.6 million years ago (red dashed line and shading) occurs well before the
appearance of tool-bearing hominin species capable of hunting large prey [Credit: John Rowan]

When and why these species disappeared has long been a mystery for archaeologists and paleontologists, despite the evolution of tool-using and meat-eating hominins getting most of the blame.


“Our analyses show that there is a steady, long-term decline of megaherbivore diversity beginning around 4.6 million years ago. This extinction process kicks in over a million years before the very earliest evidence for human ancestors making tools or butchering animal carcasses and well before the appearance of any hominin species realistically capable of hunting them, like Homo erectus,” says Faith.


Taking a Closer Look


Faith and his team quantified long-term changes in eastern African megaherbivores using a dataset of more than 100 fossil assemblages spanning the last seven million years. The team also examined independent records of climatic and environmental trends and their effects, specifically global atmospheric CO2, stable carbon isotope records of vegetation structure, and stable carbon isotopes of eastern African fossil herbivore teeth, among others.











Human ancestors not to blame for ancient mammal extinctions in Africa
The team analyzed more than 100 sites in East Africa with rich fossil records to track the longterm
decline of megaherbivore diversity [Credit: J. Tyler Faith]

Their analysis reveals that over the last seven million years substantial megaherbivore extinctions occurred: 28 lineages became extinct, leading to the present-day communities lacking in large animals. These results highlight the great diversity of ancient megaherbivore communities, with many having far more megaherbivore species than exist today across Africa as a whole.
Further analysis showed that the onset of the megaherbivore decline began roughly 4.6 million years ago, and that the rate of diversity decline did not change following the appearance of Homo erectus, a human ancestor often blamed for the extinctions. Rather, Faith’s team argues that climate is more likely culprit.


“The key factor in the Plio-Pleistocene megaherbivore decline seems to be the expansion of grasslands, which is likely related to a global drop in atmospheric CO2 over the last five million years,” says John Rowan, a postdoctoral scientist from University of Massachusetts Amherst. “Low CO2 levels favor tropical grasses over trees, and as a consequence savannas became less woody and more open through time. We know that many of the extinct megaherbivores fed on woody vegetation, so they seem to disappear alongside their food source.”


Today, Africa has five species of massive, plant-eating mammals, the so-called megaherbivores: Elephants, hippos, 


giraffes, and white and black rhinos. Millions of years ago, however, there was a much greater diversity. When and why


 these species disappeared has long been a mystery for archaeologists and paleontologists, despite the evolution of 


tool-using and meat-eating hominins getting most of the blame. New research disputes a long-held view that our 


earliest tool-bearing ancestors contributed to the demise of large mammals in Africa over the last several million 


years. Instead, the researchers argue that long-term environmental change drove the extinctions, mainly in the form 


of grassland expansion likely caused by falling atmospheric carbon dioxide levels [Credit: Lisa Potter]


The loss of massive herbivores may also account for other extinctions that have also been attributed to ancient hominins. Some scientist suggest that competition with increasingly carnivorous species of Homo led to the demise of numerous carnivores over the last few million years. Faith and his team suggest an alternative.


“We know there are also major extinctions among African carnivores at this time and that some of them, like saber-tooth cats, may have specialized on very large prey, perhaps juvenile elephants” says Paul Koch. “It could be that some of these carnivores disappeared with their megaherbivore prey.”


“Looking at all of the potential drivers of the megaherbivore decline, our analyses suggest that changing climate and environment played the key role in Africa’s past extinctions,” said Faith. “It follows that in the search for ancient hominin impacts on ancient African ecosystems, we must focus our attention on the one species known to be capable of causing them – us, Homo sapiens, over the last 300,000 years.”


The study is published today in the journal Science.


Source: University of Utah [November 22, 2018]



TANN



Archive


Well-made stone pavement found at Japan’s largest ancient tomb site

Excavation work at Japan’s largest mounded tomb has revealed that one of its surrounding greenbelts – and not just the tomb itself – was paved by many stones, signalling the massive manpower required to build it, experts said Thursday.











Well-made stone pavement found at Japan's largest ancient tomb site
The stone pavement and the remains of haniwa clay ornaments discovered at the Daisen Kofun tomb
 in Sakai’s Sakai Ward [Credit: Mainichi/Tadashi Kako]

The findings shed light as to the structure of the grave of Emperor Nintoku in Osaka Prefecture, which largely remains a mystery because the Imperial Household Agency has restricted access to the site in an effort to ensure “peace and sanctity.”
The tomb, also called Daisen Kofun and built in the fifth century, consists of a keyhole-shaped mound, alternately surrounded by three moats and two greenbelts, or dikes. From October, the agency has worked with the local government to study three locations in the inner dike as part of efforts to find ways to preserve the tomb.











Well-made stone pavement found at Japan's largest ancient tomb site
The stone pavement uncovered by excavation work at the Daisen Kofun tomb
in Sakai’s Sakai Ward [Credit: Mainichi/Tadashi Kako]

The Daisen Kofun is known as one of the three largest mounded tombs in the world, together with the Mausoleum of the First Qin Emperor in China and the Great Pyramid of Giza in Egypt.
Japan is seeking to register the Daisen Kofun and nearby tombs as a UNESCO World Cultural Heritage site next year.


Mounded tombs are usually covered with stones to avoid collapsing. But the latest survey found that all three locations at the Daisen Kofun also had the stone layer, indicating that the tomb’s inner dike, which has a total area of 65,000 square metres, was fully paved.











Well-made stone pavement found at Japan's largest ancient tomb site
The remains of a haniwa clay ornament found the Daisen Kofun tomb in Sakai’s Sakai Ward
[Credit: Mainichi/Tadashi Kako]

“This is overwhelmingly unique,” said Kazuo Ichinose, an archaeology professor at Kyoto Tachibana University, as he visited the excavation site that was shown to researchers and the press for the first time Thursday.
Ichinose said he estimated the mounded tomb to have been covered by about 50 million stones. “But if a stone pavement also existed in the dikes, the time and effort devoted to collect the stones and carry them must have been immense,” he said.


The remains of five cylindrical earthenware objects, placed in a line, were also uncovered at the site.











Well-made stone pavement found at Japan's largest ancient tomb site
Aerial view of the Daisen Kofun tomb [Credit: Mainichi/Tadashi Kako]

Katsuhisa Takahashi, a professor at Hanazono University, said the stone pavement functioned to “keep the area clean.”


“Surrounded by clay objects and white stones, we can imagine the inner dike having a sacred image like a shrine,” he said.


Some other researchers who visited the tomb in Sakai, Osaka Prefecture, called for carrying on and expanding the investigation, as well as opening the site to the public.


Source: The Mainichi [November 23, 2018]



TANN



Archive


NASA’s InSight Spacecraft Has Touched Down on Mars


NASA – InSight Mission logo.


Nov. 26, 2018


NASA’s InSight lander will complete its seven-month journey to the Red Planet.



 InSight EDL, final approach of Mars. Image Credit: NASA





Image above: NASA’s twin MarCO spacecraft are scheduled to make a flyby of Mars on Nov. 26. On Nov. 24, a wide-angle camera on MarCO-B took this picture of the Red Planet, which appears as small, grey dot in the lower left quadrant of the image. Image Credits: NASA/JPL-Caltech.



InSight Prepares to Enter Martian Atmosphere. Animation Credit: CNES

Mission controllers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have completed the final adjustments for landing NASA’s InSight spacecraft on Mars.



InSight atmospheric entry. Animation Credits: NASA/JPL-Caltech

Atmospheric entry is expected around 11:47 p.m. PST (2:47 p.m. EST) and touchdown, about seven minutes later. NASA’s InSight lander has separated from the cruise stage. It is turning to orient its heat shield in preparation for the entry, descent and landing process at Mars.



MarCO CubeSats Relaying InSight Data: Image Credit: NASA

First CubeSats to deep space — Mars Cube One A and B — have begun to relay communications from the InSight spacecraft as it lands on Mars. MarCOs’ transmissions may be interrupted during the landing process, but their signals do not affect whether InSight completes its activities.



Heat shield separation. Animation Credits: NASA/JPL-Caltech

 


InSight descent on Mars. Image Credits: NASA/JPL-Caltech

 

NASA’s InSight has begun its entry, descent and landing phase at Mars. Within seven minutes of entering the atmosphere, the spacecraft is expected to deploy its parachute, separate from its heat shield, pop out its landing legs, turn on its landing radar and start firing its retrorockets as it separates from its back shell. Touchdown is expected around 11:54 a.m. PST (2:54 p.m. EST).



 InSight Mars landing. Image Credits: NASA/JPL-Caltech

Engineers be huddled with scientists at JPL on Nov. 26, watching with nervous anticipation for signals that InSight successfully touched down, and a few seconds after… Touchdown!



Solar panels opening.  Animation Credits: NASA/JPL-Caltech


 


NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander firing retrorockets to slow down as it descends toward the surface of Mars. Credits: NASA/JPL-Caltech.



Image above: Mission controllers at NASA’s Jet Propulsion Laboratory in Pasadena, California, celebrate InSight landing mission success. Image Credit: NASA.


Mission controllers at NASA-JPL have received a signal from NASA’s InSight lander on the Mars surface via MarCO OR a beep from InSight’s X-band radio. In the coming hours, engineers will be checking on the spacecraft’s health. A post-landing news briefing expected at 2 p.m. PST (5 p.m. EST).



InSight instruments deployment. Animation Credits: NASA/JPL-Caltech

“It’s taken more than a decade to bring InSight from a concept to a spacecraft approaching Mars — and even longer since I was first inspired to try to undertake this kind of mission,” said Bruce Banerdt of JPL, InSight’s principal investigator. “But even after landing, we’ll need to be patient for the science to begin.”


It will take two to three months for InSight’s robotic arm to set the mission’s instruments on the surface. During that time, engineers will monitor the environment and photograph the terrain in front of the lander.


Back at JPL, the surface operations team will practice setting down the instruments. They’ll use a working replica of InSight in an indoor “Mars sandbox,” which will be sculpted to match the mission’s actual landing site on Mars. The team will check to make sure the instruments can be deployed safely, even if there are rocks nearby or InSight lands at an angle.



NASA’s InSight landed on Mars!

Video above: NASA’s InSight mission successfully landed on Elysium Planitia, Mars, on 26 November 2018, at around 19:54 UTC (12:54 PST, 15:54 EST). The InSight lander, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is a NASA mission designed to study Mars’ interior structure.



Animation Credits: NASA/JPL-Caltech

Once the final position of each instrument is decided, it will take several weeks to carefully lift each one and calibrate their measurements. Then the science really gets underway.


About InSight:


JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.


A number of European partners, including France’s Centre National d’Études Spatiales (CNES), the Institut de Physique du Globe de Paris (IPGP) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and IPGP provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Institute of Technology (ETH) in Switzerland, Imperial College and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.


For more detailed information on the InSight mission, visit: https://mars.nasa.gov/insight


For more information about MarCO, visit: https://www.jpl.nasa.gov/cubesat/missions/marco.php


Animations (mentioned), Images (mentioned), Video, Text, Credits: NASA/NASA TV/SciNews.


Best regards, Orbiter.chArchive link


Featured

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

Popular