пятница, 18 января 2019 г.

Successfully launch of Epsilon-4 carrying RAPIS 1

JAXA – RAPIS 1 Mission patch.

Jan. 18, 2019

Successfully of Epsilon-4 Launch With The Innovative Satellite Technology Demonstoration-1 Aboard

Epsilon-4 carrying RAPIS 1 launch

At 9:50:20 a.m. (Japan Standard Time) January 18, 2019 JAXA launched Epsilon-4, the Fourth Epsilon launch vehicle With The Innovative Satellite Technology Demonstoration-1.

National Research and Development Agency Japan Aerospace Exploration Agency (JAXA) launched the Innovative Satellite Technology Demonstration-1* aboard the fourth Epsilon Launch Vehicle (Epsilon-4) from the JAXA Uchinoura Space Center. The launch proceeded on time at 9:50:20 a.m., (Japan Standard Time, JST) January 18, 2019.

Japan Aerospace Exploration Agency’s Rapid Innovative Payload Demonstration Satellite 1, or RAPIS 1, along with six Japanese and Vietnamese secondary payloads on a rideshare mission.

Epsilon-4 launch with RAPIS-1 and Cubesats

The launch and flight of Epsilon-4 occurred nominally. All seven satellites separated from the launch vehicle successfully; the Rapid Innovative Payload Demonstration Satellite 1 (RAPIS-1) was jettisoned from the launch vehicle approximately 51 minutes 55 seconds into launch. Thereafter, other onboard satellites – MicroDragon, RISESAT, ALE-1, OrigamiSat-1, Aoba VELOX-IV and NEXUS – were respectively separated from Epsilon-4.

From the JAXA Uchinoura Space Center. The launch occurred on time. The launch and flight of Epsilon-4 took place normally. Approximately 51 minutes 55 seconds into the flight, the separation of “The Innovative Satellite Technology Demonstoration-1” proceeded, with confirmation as successful.

RAPIS-1 satellite

JAXA appreciates all for the support shown in behalf of the Epsilon-4 launch.

*Innovative Satellite Technology Demonstoration-1 is a suit of seven small satellite missions to demonstrate innovative new technological approaches;

– Rapid Innovative payload demonstration Satellite 1 (RAPIS-1), which JAXA developed with the assistance of startups

– Small satellites: MicroDragon, RISESAT and ALE-1

– CubeSats: OrigamiSat-1, Aoba VELOX-IV, NEXUS

Related links:

Epsilon Launch Vehicle: http://global.jaxa.jp/projects/rockets/epsilon/

The Innovative Satellite Technology Demonstoration-1: http://global.jaxa.jp/projects/sat/innovative/

Innovative satellite technology demonstration program (Research and Development Directorate): http://www.kenkai.jaxa.jp/eng/research/innovative/innovative.html

Images, Video, Text, Credits: Japan Aerospace Exploration Agency (JAXA)/National Research and Development Agency/SciNews.

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Primitive microbes found to have cytoskeletal proteins similar to those found in humans

The recent discovery of a new lineage of microbes has overturned biologists’ understanding of the evolution of complex life on Earth. Genomic studies of Asgard archaea revealed that they carry many genes previously thought to be found only in nucleus-bearing eukaryotes, suggesting they may be closely related to more complex life forms such as humans.

Primitive microbes found to have cytoskeletal proteins similar to those found in humans
The Norse god Loki holding a Lokiarchaeota profilin protein crystal standing in front of Lokiarchaeota profilin/rabbit
actin crystals [Credit: Protein crystal images © 2018 A*STAR Institute of Molecular and Cell Biology;
Image of Loki from manuscript SÁM 66 of the Árni Magnússon Institute for Icelandic Studies]

Two A*STAR scientists have now strengthened the case for this evolutionary scenario by showing that these small creatures have a dynamic network of cytoskeletal proteins, a feature that gives cells shape, and was previously thought of as specific to eukaryotes.

What’s more, the A*STAR investigators found that one of these archaeal proteins, profilin, that serves to bind and regulate the dynamics of a cytoskeletal protein called actin—had the same function as its counterpart in eukaryotes. The primordial profilin could even bind actin derived from a mammal.

“After around two billion years of divergent evolution, it is staggering that these proteins are compatible,” says Robert Robinson, a research director at the A*STAR Institute of Molecular and Cell Biology, who led the study published in Nature.

Scientists in Sweden first identified Asgard archaea in 2015, from sediments taken deep below the Arctic Ocean, near a series of hydrothermal vents called Loki’s Castle. Those microbes became known as Lokiarchaeota, named after the Norse shape-shifting god, and every Asgard lineage found thereafter—as well as the word Asgard—has come from Norse mythology.

No Asgard archaea have yet been grown in the laboratory or observed under a microscope. So, Robinson and his graduate student Caner Akıl took gene sequences encoding profilin proteins from a few Asgard lineages and inserted the DNA into an easily cultured bacterium. They then purified the profilins made by the bacterium and worked out the protein structures using X-ray crystallography.

Although these proteins shared little sequence similarity at the amino acid level with their eukaryotic counterparts, the researchers discovered that the overall shape of Asgard and human profilins were topologically alike—a sign of evolutionary links.

Robinson and Akıl were not able to produce functional Asgard actin, profilin’s binding partner, in their bacterial expression system. As an alternative, they used rabbit actin and tested whether Asgard profilin could bind to the actin and modulate its kinetics.

Indeed, the Asgard protein tethered and regulated the mammalian actin only slightly less efficiently than profilin from humans. Considered together, these results indicate that Asgard archaea, unlike other organisms lacking a nucleus, harbor a primitive, but dynamic cytoskeleton, and thus probably shared a common ancestor with eukaryotes some two billion years ago.

“We are now comparing other eukaryotic-like Asgard proteins to the human counterparts,” Robinson says. “We hope to understand how the eukaryotic protein machineries became more sophisticated over time.”

Source: Agency for Science, Technology and Research (A*STAR), Singapore [January 15, 2019]



Differentiating summer and winter rainfall in South Asia around 4.2 ka climatic...

Climate change has the potential to have affected ancient civilizations by spurring migrations and changes in cropping strategies, and these questions are increasingly relevant as we look at how modern civilization is coping with climate change today.

Differentiating summer and winter rainfall in South Asia around 4.2 ka climatic 'event'
Credit: University of Cambridge

An article published in a special issue of Climate of the Past on the “4.2 ka BP climatic event” provides rich insights into how rainfall in the northwest of South Asia changed over the critical period between 5400 and 3000 years ago.

The marine sediment core known as 63KA was taken close to the mouth of the Indus River delta and holds important and intriguing information about past changes in river discharge and depth of ocean stratification. The discharge of the Indus River is directly linked to the amount of summer rainfall. Ocean mixing depth is related to the strength of winds and evaporation over the Arabian Sea during wintertime that, in turn, correlates with winter precipitation over northwestern India. Three species of planktonic foraminifera with distinct ecological niches have been used to track relevant changes in salinity and temperature by measuring the oxygen isotopes from their calcareous shells, which produce a synchronous record of summer and winter monsoon strength.

Work on samples from this marine core attracted wide interest in 2003 when a summer monsoon mega-drought around 4.2 thousand years ago was related to cultural transformations of the Indus Civilization, which had an urban phase spanning from c.4.5-3.9 thousand years ago.

Prof. Michael Staubwasser from the University of Cologne, who was lead author of the 2003 paper and is co-author on the latest research, safeguarded samples from this core for over 20 years. “We always thought there might be more valuable information left in these samples,” he says, “and we can now see that it is possible to track both summer and winter precipitation from the same core.”

Differentiating summer and winter rainfall in South Asia around 4.2 ka climatic 'event'
Credit: University of Cambridge

The new results point to a 200-year period of abnormally strong winter precipitation between c.4.5-4.3 thousand years ago, and after this, winter and summer rainfall both decreased to a minimum at c.4.1 thousand years ago.

“Humans are completely dependent on constant access to water. The possibility of a simultaneous decrease in winter precipitation by 4.1 thousand years ago completely changes the picture of year-round water availability in this region. A shift from plentiful winter rain to the totally opposite extreme, in combination with summer monsoon rains that were already declining, will have had a dramatic impact upon the people living in this region” says Alena Giesche, lead author on the new publication and PhD candidate in Earth Sciences at the University of Cambridge.

Climatic changes during this time period coincide with important cultural changes in the Indus Civilization, which saw the culmination of a process of deurbanisation by c. 3.9 thousand years ago. “This finding has important implications for our understanding of the Indus Civilization, particularly our interpretation of changes in settlement patterns and cropping strategies. There was clear decline in the major urbanized centres, but there was also an increase in the numbers of rural settlements in the summer monsoon-dominated regions in the east, suggesting that populations adapted to changing conditions,” says Dr. Cameron Petrie, co-author and Reader in Archaeology at the University of Cambridge.

The new results are particularly exciting because they track two rainfall regimes in the same exact core. “This is a unique core, because the sediments are laminated and not disturbed by mixing by organisms (bioturbation). It has a detailed radiocarbon chronology and because proxies for both the summer and winter rainfall are recorded in the same samples, the relative timing of the two can be determined with confidence,” says Prof. David Hodell, co-author and Woodwardian Professor of Geology at the University of Cambridge.

Source: University of Cambridge [January 15, 2019]



11,500-year-old animal bones in Jordan suggest early dogs helped humans hunt

11,500 years ago in what is now northeast Jordan, people began to live alongside dogs and may also have used them for hunting, a new study from the University of Copenhagen shows. The archaeologists suggest that the introduction of dogs as hunting aids may explain the dramatic increase of hares and other small prey in the archaeological remains at the site.

11,500-year-old animal bones in Jordan suggest early dogs helped humans hunt
Selection of gazelle bones from Space 3 at Shubayqa 6 displaying evidence for having been
 in the digestive tract of a carnivore [Credit: University of Copenhagen]

Dogs were domesticated by humans as early as 14,000 years ago in the Near East, but whether this was accidental or on purpose is so far not clear. New research published in the Journal of Anthropological Archaeology by a team of archaeologists from the University of Copenhagen and University College London may suggest that humans valued the tracking and hunting abilities of early dogs more than previously known.

A study of animal bones from the 11,500 year old settlement Shubayqa 6 in northeast Jordan not only suggests that dogs were present in this region at the start of the Neolithic period, but that humans and dogs likely hunted animals together:

“The study of the large assemblage of animal bones from Shubayqa 6 revealed a large proportion of bones with unmistakable signs of having passed through the digestive tract of another animal; these bones are so large that they cannot have been swallowed by humans, but must have been digested by dogs,” explained zooarchaeologist and the study’s lead author Lisa Yeomans.

Lisa Yeomans and her colleagues have been able to show that Shubayqa 6 was occupied year round, which suggests that the dogs were living together with the humans rather than visiting the site when there were no inhabitants:

11,500-year-old animal bones in Jordan suggest early dogs helped humans hunt
One of the excavated structures at the Shubayqa 6 site [Credit: University of Copenhagen]

“The dogs were not kept at the fringes of the settlement, but must have been closely integrated into all aspects of day-to-day life and allowed to freely roam around the settlement, feeding on discarded bones and defecating in and around the site.”

Can new hunting techniques account for the increase in small prey?

When Yeomans and her co-authors sifted through the analysed data, they also noted a curious increase in the number of hares at the time that dogs appeared at Shubayqa 6. Hares were hunted for their meat, but Shubayqa 6’s inhabitants also used the hare bones to make beads. The team think that it is likely that the appearance of dogs and the increase in hares are related.

“The use of dogs for hunting smaller, fast prey such as hares and foxes, perhaps driving them into enclosures, could provide an explanation that is in line with the evidence we have gathered. The long history of dog use, to hunt both small as well as larger prey, in the region is well known, and it would be strange not to consider hunting aided by dogs as a likely explanation for the sudden abundance of smaller prey in the archaeological record,” said Lisa Yeomans.

“The shift may also be associated with a change in hunting technique from a method, such as netting, that saw an unselective portion of the hare population captured, to a selective method of hunting in which individual animals were targeted. This could have been achieved by dogs.”

Source: University of Copenhagen [January 15, 2019]



New insights into what Neolithic people ate in Southeastern Europe

New research, led by the University of Bristol, has shed new light on the eating habits of Neolithic people living in southeastern Europe using food residues from pottery extracts dating back more than 8,000 years.

New insights into what Neolithic people ate in Southeastern Europe
The Iron Gates gorges and, inset, a reconstructed Starčevo pot
[Credit: C. Bonsall and M. Toderaș]

With the dawn of the Neolithic age, farming became established across Europe and people turned their back on aquatic resources, a food source more typical of the earlier Mesolithic period, instead preferring to eat meat and dairy products from domesticated animals.

The research, published today in the journal Royal Society Proceedings B, reveals that people living in the Iron Gates region of the Danube continued regular fish-processing, whereas pottery extracts previously examined from hundreds of sherds elsewhere in Europe show that meat and dairy was the main food source in pots.

This region is archaeologically very important because the sites document Late Mesolithic forager settlements and the first appearance of Neolithic culture, which is spreading up through Europe illustrated by the first appearances of pottery, domesticated plants and animals and different burial styles.

The Iron Gates is a unique landscape on the border between modern-day Romania and Serbia where the Danube cuts through the junction of the Balkan and Carpathian mountain chains. It provided a rich wild aquatic resource base for prehistoric hunter-fisher-foragers during the Late Glacial and early Holocene.

As farming spread from south west Asia into Europe, prehistoric diets ultimately transformed towards a diet based upon domesticated plants and animals. However, in this region, evidence has suggested that wild resources may have continued to be important well into the early Neolithic.

This research involved analysis of organic residues surviving in the fabric of 8,000-year-old Neolithic pottery excavated from sites on the banks of the Danube.

Chemical analyses allowed scientists to directly see what kinds of resources were being prepared in these newly-appearing pots and compare this with the way the same type of pottery was being used by farmers in the wider Balkans region.

Dr Lucy Cramp from the University of Bristol’s Department of Anthropology and Archaeology, led the research. She said: “The findings revealed that the majority of Neolithic pots analysed here were being used for processing fish or other aquatic resources.

“This is a significant contrast with an earlier study showing the same type of pottery in the surrounding region was being used for cattle, sheep or goat meat and dairy products.

“It is also completely different to nearly all other assemblages of Neolithic farmer-type pottery previously analysed from across Europe (nearly 1,000 residues) which also show predominantly terrestrial- based resources being prepared in cooking pots (cattle/sheep/goat, possibly also deer), even from locations near major rivers or the coast.”

The research team suggest that this unusual dietary/subsistence pattern may be for several reasons.

It is possible that farmers were attracted to this location by the impressive aquatic resources available including huge sturgeon which swam up the river from the Black Sea.

It may also be that Late Mesolithic dietary practices are continuing here, but now using new Neolithic pottery as a result of these early interactions between Mesolithic and Neolithic communities.

Source: University of Bristol [January 15, 2019]



The pace at which the world’s permafrost soils are warming

Global warming is leaving more and more apparent scars in the world’s permafrost regions. As the new global comparative study conducted by the international permafrost network GTN-P shows, in all regions with permafrost soils the temperature of the frozen ground at a depth of more than 10 metres rose by an average of 0.3 degrees Celsius between 2007 and 2016 – in the Arctic and Antarctic, as well as the high mountain ranges of Europe and Central Asia. The effect was most pronounced in Siberia, where the temperature of the frozen soil rose by nearly 1 degree Celsius. The pioneering study has just been released in the online journal Nature Communications.

The pace at which the world's permafrost soils are warming
AWI permafrost scientists investigate the eroding coastline at the Siberian island Sobo-Sise, Eastern Lena delta
[Credit: Guido Grosse]

Roughly one sixth of the land areas on our planet are considered to be permafrost regions, which means the soils there have remained permanently frozen for at least two consecutive years. In most of these regions, however, the cold penetrated the ground millennia ago; as a result, in the most extreme cases, the permafrost continues to a depth of 1.6 kilometres. Especially in the Arctic, people rely on the permafrost soil as a stable foundation for houses, roads, pipelines and airports.
Yet in the wake of global warming, the integrity of these structures is increasingly jeopardised, creating enormous costs. In addition, permafrost soils contain massive quantities of preserved plant and animal matter. If this organic material thaws along with the permafrost, microorganisms will begin breaking it down – a process that could produce enough carbon dioxide and methane emissions to potentially raise the global mean temperature by an additional 0.13 to 0.27 degrees Celsius by the year 2100.

The pace at which the world's permafrost soils are warming
Image from the Lena spring flood at Samoylov. Once a year the river carries massive amounts of ice towards the Arctic
 Ocean. The floats often get stucked at the shoreline and build big icy dams [Credit: Torsten Sachs]

A new comparative study released by the GTN-P (Global Terrestrial Network for Permafrost) shows for the first time the extent to which permafrost soils around the world have already warmed. For the purposes of the study, the participating researchers monitored and analysed the soil temperature in boreholes in the Arctic, Antarctic and various high mountain ranges around the world for ten years. The data was gathered at depths greater than 10 metres, so as to rule out the influence of seasonal temperature variations.
The complete dataset encompasses 154 boreholes, 123 of which allow conclusions to be drawn for an entire decade, while the remainder can be used to refine calculations on annual deviation. The results show that, in the ten years from 2007 to 2016, the temperature of the permafrost soil rose at 71 of the 123 measuring sites; in five of the boreholes, the permafrost was already thawing. In contrast, the soil temperature sank at 12 boreholes, e.g. at individual sites in eastern Canada, southern Eurasia and on the Antarctic Peninsula; at 40 boreholes, the temperature remained virtually unchanged.

In individual cases, temperature spiked up to 1 degree Celsius

The researchers observed the most dramatic warming in the Arctic: “There, in regions with more than 90 percent permafrost content, the soil temperature rose by an average of 0.30 degrees Celsius within ten years,” reports first author Dr Boris Biskaborn, a member of the research group Polar Terrestrial Environmental Systems at the Potsdam facilities of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. In northeast and northwest Siberia, the temperature increase at some boreholes was 0.90 degrees Celsius or even higher. For the sake of comparison: the air temperature in the respective regions rose by an average of 0.61 degrees Celsius in the same period.

The pace at which the world's permafrost soils are warming
Lena spring flood at Samoylov [Credit: Torsten Sachs]

Farther south, in Arctic regions with less than 90 percent permafrost, the frozen ground only warmed by 0.2 degrees Celsius on average. “In these regions there is more and more snowfall, which insulates the permafrost in two ways, following the igloo principle: in winter the snow protects the soil from extreme cold, which on average produces a warming effect. In spring it reflects the sunlight, and prevents the soil from being exposed to too much warmth, at least until the snow has completely melted away,” Biskaborn explains.
Significant warming can also be seen in the permafrost regions of the high mountain ranges, and in the Antarctic. The temperature of the permanently frozen soils in the Alps, in the Himalayas and in the mountain ranges of the Nordic countries rose by an average of 0.19 degrees Celsius. In the shallow boreholes in the Antarctic, the researchers measured a rise of 0.37 degrees.

The pace at which the world's permafrost soils are warming
Aerial photo of the Russian tundra [Credit: Torsten Sachs]

“All this data tells us that the permafrost isn’t simply warming on a local and regional scale, but worldwide and at virtually the same pace as climate warming, which is producing a substantial warming of the air and increased snow thickness, especially in the Arctic. These two factors in turn produce a warming of the once permanently frozen ground,” says Prof. Guido Grosse, Head of the Permafrost Research Section at the Alfred Wegener Institute in Potsdam.

Permafrost monitoring calls for an institutional framework

These revealing insights are the reward for a decade-long international collaboration that involved experts from 26 countries. The majority of the boreholes used in the study were drilled and equipped with measuring equipment during the International Polar Year 2007/08, and offered a first “snapshot” of the permafrost temperatures. Since then, more than 50 different research groups have performed regular maintenance on the measuring stations, and recorded their readings on an annual basis. In the virtual network GTN-P, the findings were subsequently collated and standardised, ensuring their intercomparability.

The pace at which the world's permafrost soils are warming
Lake and ponds at the foothills of the Brooks Range, Alaska [Credit: Josefine Lenz]

According to Prof. Hanne H. Christiansen, co-author of the study and President of the International Permafrost Association (IPA), “Monitoring global permafrost temperatures and gathering the data in the freely accessible GTN-P database is tremendously important – and not just for researchers, educators and communicators, but for various other users.”
“The permafrost temperature is one of the most universally accepted climate variables. It offers a direct insight into how the frozen ground is reacting to climate change,” the researcher explains. This information is above all essential in those permafrost regions where the soil has already grown warmer or begun thawing, producing major damage when the ground buckles, destabilising roads and buildings. Accordingly, the researchers plan to continue monitoring the boreholes.

The pace at which the world's permafrost soils are warming
Drainage channel of a freshly drained basin near Cape Halkett. The lake drained catastrophically 40 days ago,
North Slope Alaska [Credit: Josefine Lenz]

Unlike weather observations, there is still no single international institution that, following in the footsteps of the World Meteorological Organization (WMO), successfully bundles national interests. Such an institution would be an essential asset in terms of coordinating these important scientific measurements, and to ensure the monitoring sites continue to be used in the future.
To date, the permafrost boreholes and the temperature sensors installed in them have been kept up and running by individual research groups in the context of various small-scale projects. The Global Terrestrial Network for Permafrost (GTN-P) offers a web-based data management system, which was jointly developed by the Alfred Wegener Institute and the Iceland-based Arctic Portal, and was made possible by the financial support of the European Union.

Source: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research [January 16, 2019]



Ice Age climate caused sediment sourcing 180 in Gulf of Mexico

The onset of the most recent ice age about 2.6 million years ago changed where the western Gulf of Mexico gets its supply of sediments. The finding adds new insight into how extreme climate change can directly impact fundamental geological processes and how those impacts play out across different environments.

Ice Age climate caused sediment sourcing 180 in Gulf of Mexico

Ice Age climate caused sediment sourcing 180 in Gulf of Mexico
Scenarios for sediment supply to the western Gulf of Mexico in the Miocene (A) and Pleistocene (B.) Sediment-source area
for Miocene is shown in green; Laurentide and Cordilleran ice sheets and Rocky Mountain glaciers are in blue.
Open circles are Deep Sea Drilling Project (DSDP) study sites [Credit: Hessler et al. 2018]

The research found that the same climatic changes that grew glaciers across the northern hemisphere reduced sediment production in southern Mexico while ramping up sediment production along the catchment of the Mississippi River.

The Gulf of Mexico has been catching sediments transported by rivers for about 200 million years. The layers of sediments that accumulate on the seafloor record information about the origin of the sediments and the erosive processes that lifted them from the rock. In this study, the scientists examined sediments deposited during the 20-million-year transition from the Miocene to the Pleistocene, when the Earth’s climate transitioned from a relatively warm period to an ice age.

“It’s an important transition climate-wise,” said Hessler. “Climate cycles changed, and it’s possible that changed the erodibility and the transport mechanism across North America to be able to shed all this material out toward Mexico.”

Based on the composition of the sediments, the researchers were able to determine that the primary supply of sediments during the middle-to-late Miocene came from rivers in southern Mexico. This came as a surprise because of the rivers’ relatively small catchment – an area in the tropical highlands of Mexico about 300-by-500-square kilometers, or about the size of Illinois. However, the sediments revealed that what the area lacked in size it made up for with highly erodible conditions, including a wet climate and tectonic activity such as uplifting mountains and volcanoes.

But that environment changed with the global cooling of the Pleistocene. The highlands became dry and arid. And while tectonic activity still continued, the lack of precipitation meant that the fresh bedrock and volcanic debris largely stayed in place. In what is now the United States, large ice sheets started to form and erode rock as they flowed across the continent.

The study found that this extreme climate shift is reflected by a change in sediments. By the mid-Pleistocene, almost all the sediments in the Gulf of Mexico came from the north via the Mississippi River, which collected sediments from waterways across the continent.

The study was able to unpack so much about the age, origin and environment of the sediments because of thorough research methods that examined the mud created by the sediments along with the grains, said Stockli.

“One of the really cool things about this paper is that there haven’t been that many studies that actually combine the two records,” he said. “People traditionally don’t do that much with the muck, but that clay tells us so much about the weathering, and what those conditions are.”

The methods used by the scientists included, microscope observations of sand grains, geochemical analyses of trace elements in sediment muds using mass spectrometry, and zircon U-Pb isotope analyses. The sediments themselves came from five core samples that were retrieved from across the Gulf of Mexico by the Deep Sea Drilling Project, the precursor to the International Ocean Discovery Program, about 50 years ago.

Studying how the Earth’s climate impacts sediment transport helps researchers understand the connection between climate change and other geological processes. This connection could be an important point to consider when predicting the future impacts of climate change on the rest of the natural world.

“All this information about provenance, and how things interacted at one time or another, or climate – it’s all contained in this stratigraphic archive,” said Covault. “It just takes a couple people to interrogate the heck out of it and put together a really interesting story that has implications beyond the Gulf of Mexico, for other places that might be subjected to climate change.”

The study was published in the journal Geology.

Source: University of Texas at Austin [January 16, 2019]



Geological fingerprinting of volcanic ash…

Geological fingerprinting of volcanic ash http://www.geologypage.com/2019/01/geological-fingerprinting-of-volcanic-ash.html

Scientists find increase in asteroid impacts on ancient Earth by…

Scientists find increase in asteroid impacts on ancient Earth by studying the Moon http://www.geologypage.com/2019/01/scientists-find-increase-in-asteroid-impacts-on-ancient-earth-by-studying-the-moon.html

New study quantifies deep reaction behind ‘superdeep’ diamonds…

New study quantifies deep reaction behind ‘superdeep’ diamonds http://www.geologypage.com/2019/01/new-study-quantifies-deep-reaction-behind-superdeep-diamonds.html

2019 January 18 Circumpolar Star Trails Image Credit &…

2019 January 18

Circumpolar Star Trails
Image Credit & Copyright: Gabriel Funes

Explanation: As Earth spins on its axis, the stars appear to rotate around an observatory in this well-composed image from the Canary Island of Tenerife. Of course, the colorful concentric arcs traced out by the stars are really centered on the planet’s North Celestial Pole. Convenient for northern hemisphere astro-imagers and celestial navigators alike, bright star Polaris is near the pole and positioned in this scene to be behind the telescope dome. Made with a camera fixed to a tripod, the series of over 200 stacked digital exposures spanned about 4 hours. The observatory was not operating on that clear, dark night, but that’s not surprising. The dome houses the Teide Observatory’s large THEMIS Solar Telescope.

∞ Source: apod.nasa.gov/apod/ap190118.html

NASA’s Moon Data Sheds Light on Earth’s Asteroid Impact History

NASA – Lunar Reconnaissance Orbiter (LRO) patch.

Jan. 17, 2019

By looking at the Moon, the most complete and accessible chronicle of the asteroid collisions that carved our young solar system, a group of scientists is challenging our understanding of a part of Earth’s history.

Image above: The image shows a waning crescent Moon. Plotted on the night side is the LRO Diviner rock abundance map. The most prominent craters visible in the map are Tycho (85 million years old), Copernicus (797 million years old), and Aristarchus (164 million years old). The terminator passes through the Aristarchus plateau, dividing Aristarchus from its sister crater, Herodotus. Image Credits: Ernie Wright/NASA Goddard.

The number of asteroid impacts to the Moon and Earth increased by two to three times starting around 290 million years ago, researchers reported in a paper in the journal Science.

They could tell by creating the first comprehensive timeline of large craters on the Moon formed in the last billion years by using images and thermal data collected by NASA’s Lunar Reconnaissance Orbiter (LRO). When the scientists compared those to the timeline of Earth’s craters, they found the two bodies had recorded the same history of asteroid bombardment—one that contradicts theories about Earth’s impact rate.

For decades, scientists have tried to understand the rate that asteroids hit the Earth by carefully studying impact craters on continents and by using radiometric dating of the rocks around them to determine the ages of the largest, and thus most intact, ones. The problem is that many experts assumed that early Earth craters have been worn away by wind, storms, and other geologic processes. This idea explained why Earth has fewer older craters than expected compared to other bodies in the solar system, but it made it difficult to find an accurate impact rate and to determine whether it had changed over time.  

Image above: NASA’s Landsat 7 satellite captured this image of Pingualuit Crater on August 17, 2002. In it, water appears blue, and land appears in varying shades of beige. With a diameter of 2.14 miles (3.44 kilometers), Pingualuit Crater holds a lake about 876 feet (267 meters) deep. Image Credit: NASA.

A way to sidestep this problem is to examine the Moon. Earth and the Moon are hit in the same proportions over time. In general, because of its larger size and higher gravity, about twenty asteroids strike Earth for every one that strikes the Moon, though large impacts on either body are rare. But even though large lunar craters have experienced little erosion over billions of years, and thus offer scientists a valuable record, there was no way to determine their ages until the Lunar Reconnaissance Orbiter started circling the Moon a decade ago and studying its surface.

“We’ve known since the Apollo exploration of the Moon 50 years ago that understanding the lunar surface is critical to revealing the history of the solar system,” said Noah Petro, an LRO project scientist based at NASA Goddard Space Flight Center in Greenbelt, Maryland. LRO, along with new commercial robotic landers under development with NASA, said Petro, will inform the development and deployment of future landers and other exploration systems needed for humans to return to the Moon’s surface and to help prepare the agency to send astronauts to explore Mars. Achieving NASA’s exploration goals is dependent on the agency’s science efforts, which will contribute to the capabilities and knowledge that will enable America’s Moon to Mars exploration approach now and in the future.

“LRO has proved an invaluable science tool,” said Petro. “One thing its instruments have allowed us to do is peer back in time at the forces that shaped the Moon; as we can see with the asteroid impact revelation, this has led to groundbreaking discoveries that have changed our view of Earth.”

Image above: A 2014 Lunar Reconnaissance Orbiter Camera image showing two similarly sized craters in Mare Tranquillitatis. Both are about 500 meters in diameter. One is littered with boulders and the other is not. This boulder discrepancy is likely due to age differences between the two craters. Image width is about 2 kilometers. North points up. Image Credits: NASA/GSFC/Arizona State University.

The Moon as Earth’s Mirror

LRO’s thermal radiometer, called Diviner, has taught scientists how much heat is radiating off the Moon’s surface, a critical factor in determining crater ages. By looking at this radiated heat during the lunar night, scientists can calculate how much of the surface is covered by large, warm rocks, versus cooler, fine-grained regolith, also known as lunar soil.

Large craters formed by asteroid impacts in the last billion years are covered by boulders and rocks, while older craters have few rocks, Diviner data showed. This happens because impacts excavate lunar boulders that are ground into soil over tens to hundreds of millions of years by a constant rain of tiny meteorites.

Image above: Geologist-Astronaut Harrison H. Schmitt is photographed standing next to a huge, split boulder at Station 6 on the sloping base of North Massif during the third Apollo 17 extravehicular activity (EVA-3) at the Taurus-Littrow landing site. The “Rover” Lunar Roving Vehicle (LRV) is in the left foreground. Schmitt is the Apollo 17 Lunar Module pilot. This picture was taken by Commander Eugene A. Cernan on n December 13, 1972. Image Credit: NASA.

Paper co-author Rebecca Ghent, a planetary scientist at University of Toronto and the Planetary Science Institute in Tucson, Arizona, calculated in 2014 the rate at which Moon rocks break down into soil. Her work thus revealed a relationship between an abundance of large rocks near a crater and the crater’s age. Using Ghent’s technique, the team assembled a list of ages of all lunar craters younger than about a billion years.

“It was a painstaking task, at first, to look through all of these data and map the craters out without knowing whether we would get anywhere or not,” said Sara Mazrouei, the lead author of the Science paper who collected and analyzed all the data for this project while a Ph.D. student at the University of Toronto.

The work paid off, returning several unexpected findings. First, the team discovered that the rate of large crater formation on the Moon has been two to three times higher over approximately the last 290 million years than it had been over the previous 700 million years. The reason for this jump in the impact rate is unknown. It might be related to large collisions taking place more than 300 million years ago in the main asteroid belt between the orbits of Mars and Jupiter, the researchers noted. Such events can create debris that can reach the inner solar system.  

The second surprise came from comparing the ages of large craters on the Moon to those on Earth. Their similar number and ages challenges the theory that Earth had lost so many craters through erosion that an impact rate could not be calculated.

“The Earth has fewer older craters on its most stable regions not because of erosion, but because the impact rate was lower about 290 million years ago,” said William Bottke, an asteroid expert at the Southwest Research Institute in Boulder, Colorado and a co-author of the paper. “This meant the answer to Earth’s impact rate was staring everyone right in the face.”

Moon Sheds Light on Earth’s Impact History

Video above: By analyzing data on lunar craters provided by the Diviner instrument aboard the Lunar Reconnaissance Orbiter, scientists have made a fascinating discovery about the history of impacts on both the Earth and the Moon. Video Credits: Ernie Wright & David Ladd/NASA Goddard.

Proving that fewer craters meant fewer impacts—rather than loss through erosion—posed a formidable challenge. Yet the scientists found strong supporting evidence for their findings through a collaboration with Thomas Gernon, an Earth scientist based at the University of Southampton in England who works on a terrestrial feature called kimberlite pipes.

These underground pipes are long-extinct volcanoes that stretch, in a carrot shape, a couple of kilometers below the surface. Scientists know a lot about the ages and rate of erosion of kimberlite pipes because they are widely mined for diamonds. They also are located on some of the least eroded regions of Earth, the same places we find preserved impact craters.

Gernon showed that kimberlite pipes formed since about 650 million years ago had not experienced much erosion, indicating that the large impact craters younger than this on stable terrains must also be intact. “So that’s how we know those craters represent a near-complete record,” Ghent said.

Lunar Reconnaissance Orbiter (LRO). Image Credits: NASA/JPL

Ghent’s team, which also included Southwest Research Institute planetary astronomer Alex Parker, wasn’t the first to propose that the rate of asteroid strikes to Earth has fluctuated over the past billion years. But it was the first to show it statistically and to quantify the rate. Now the team’s technique can be used to study the surfaces of other planets to find out if they might also show more impacts.

The team’s findings related to Earth, meanwhile, may have implications for the history of life, which is punctuated by extinction events and rapid evolution of new species. Though the forces driving these events are complicated and may include other geologic causes, such as large volcanic eruptions, combined with biological factors, the team points out that asteroid impacts have surely played a role in this ongoing saga. The question is whether the predicted change in asteroid impacts can be directly linked to events that occurred long ago on Earth.

This research was funded in part by NASA’s Solar System Exploration Research Virtual Institute (SSERVI). Researchers at the Southwest Research Institute are part of 13 teams within SSERVI, based and managed at NASA’s Ames Research Center in California’s Silicon Valley. SSERVI is funded by the Science Mission Directorate and Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington, DC.

Related link:

LRO (Lunar Reconnaissance Orbiter): http://www.nasa.gov/mission_pages/LRO/main/index.html

Image (mentioned), Video (mentioned), Text, Credits: NASA/Svetlana Shekhtman/Goddard Space Flight Center, by Lonnie Shekhtman.

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NASA’s Cassini Data Show Saturn’s Rings Relatively New

NASA – Cassini Mission to Saturn patch.

Jan. 17, 2019

The rings of Saturn may be iconic, but there was a time when the majestic gas giant existed without its distinctive halo. In fact, the rings may have formed much later than the planet itself, according to a new analysis of gravity science data from NASA’s Cassini spacecraft.

Image above: An artist’s concept of the Cassini orbiter crossing Saturn’s ring plane. New measurements of the rings’ mass give scientists the best answer yet to the question of their age. Image Credits: NASA/JPL-Caltech.

The findings indicate that Saturn’s rings formed between 10 million and 100 million years ago. From our planet’s perspective, that means Saturn’s rings may have formed during the age of dinosaurs.

The conclusions of the research — gleaned from measurements collected during the final, ultra-close orbits Cassini performed in 2017 as the spacecraft neared the end of its mission — are the best answer yet to a longstanding question in solar system science. The findings were published online Jan. 17 in Science.

Saturn formed 4.5 billion years ago, in the early years of our solar system. There have been clues that its ring system is a young upstart that attached to Saturn years afterward. But how long afterward?

To figure out the age of the rings, scientists needed to measure something else: the mass of the rings, or how much material they hold. Researchers had the remote-sensing measurements from Cassini and both of NASA’s Voyager spacecraft in the early 1980s. Then came Cassini’s unprecedented, up-close data from its final orbits. As the spacecraft was running out of fuel, it performed 22 dives between the planet and the rings.

The dives allowed the spacecraft to act as a probe, falling into Saturn’s gravity field, where it could feel the tug of the planet and the rings. Radio signals sent to Cassini from the antennas of NASA’s Deep Space Network and the European Space Agency relayed the spacecraft’s velocity and acceleration.

Once scientists knew how much gravity was pulling on Cassini, causing it to accelerate — down to a fraction of a millimeter per second — they could determine how massive the planet is and how massive the rings are.

“Only by getting so close to Saturn in Cassini’s final orbits were we able to gather the measurements to make the new discoveries,” said Cassini radio science team member and lead author Luciano Iess, of Sapienza University of Rome. “And with this work, Cassini fulfills a fundamental goal of its mission: not only to determine the mass of the rings, but to use the information to refine models and determine the age of the rings.”

Iess’ paper builds on a connection scientists previously made between the mass of the rings and their age. Lower mass points to a younger age, because the rings, which are bright and mostly made of ice, would have been contaminated and darkened by interplanetary debris over a longer period. With a better calculation of ring mass, scientists were better able to estimate the rings’ age.

Saturn scientists will continue work to figure out how the rings formed. The new evidence of young rings lends credence to theories that they formed from a comet that wandered too close and was torn apart by Saturn’s gravity — or by an event that broke up an earlier generation of icy moons.

Rotating Layers Go Deep

From Cassini’s super-close vantage point, immersed in Saturn’s gravity field, the spacecraft relayed measurements that led scientists to another surprising discovery.

It’s long been known that Saturn’s equatorial atmosphere rotates around the planet faster than its inner layers and core. Imagine a set of nested cylinders, rotating at different speeds. Eventually, toward the center of the planet, the layers move in synchrony and rotate together.

Jupiter’s atmosphere behaves like this, too. But the new findings show that Saturn’s layers start rotating in synchrony much deeper into the planet — at least 5,600 miles (9,000 kilometers) in. That’s three times deeper than the same phenomenon at Jupiter. It’s a depth that equals 15 percent of Saturn’s entire radius.

“The discovery of deeply rotating layers is a surprising revelation about the internal structure of the planet,” said Cassini Project Scientist Linda Spilker of JPL. “The questions are what causes the more rapidly rotating part of the atmosphere to go so deep, and what does that tell us about Saturn’s interior?”

At the same time, the measurement of Saturn’s gravity solved yet another unknown: the mass of the core. Models of the interior developed by Burkhard Militzer, a UC Berkeley professor and a co-author of the paper, indicate that it is 15 to 18 Earth masses.

Cassini’s mission ended in September 2017, when it was low on fuel and deliberately plunged into Saturn’s atmosphere to protect the planet’s moons. More science from the last orbits, known as the Grand Finale, will be published in the coming months.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency (ESA) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA’s Science Mission Directorate in Washington. JPL designed, developed and assembled the Cassini orbiter. The radio science instrument was built by JPL and the Italian Space Agency, working with team members from the U.S. and Italy.

For more information about Cassini, go to: https://solarsystem.nasa.gov/cassini

Image (mentioned), Text, Credits: NASA/Tony Greicius/JoAnna Wendel/JPL/Gretchen McCartney.

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Ri Cruin Prehistoric Burial Cairn, Kilmartin Glen, Argyll, 12.1.19.

Ri Cruin Prehistoric Burial Cairn, Kilmartin Glen, Argyll, 12.1.19.

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Temple Wood Stone Circle 1, Kilmartin Glen, Argyll, Scotland, 12.1.19.

Temple Wood Stone Circle 1, Kilmartin Glen, Argyll, Scotland, 12.1.19.

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https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...