вторник, 30 апреля 2019 г.

Research examines new links between retreating glaciers and global warming

University of Southampton scientists are using innovative technology to monitor the behaviour of glaciers in real time, in a new bid to understand the link between their retreat, global warming and rising sea levels.

Research examines new links between retreating glaciers and global warming
Increased volume of glacier melt water is increasing the speed in which glaciers are retreating
[Credit: University of Southampton]

The Southampton researchers, who are part of the international Glacsweb project, have developed technology to monitor glacier behaviour. They have used unique sensor probes placed in, on and underneath the glacial ice. These sensor probes measure temperature, pressure, stress, weather and subglacial movement.

The information gathered is important in understanding a glacier’s dynamics and this data helps the team to study climate change.

As part of the team’s latest investigation, data retrieved from probes in Skálafellsjökull, Iceland, showed that the increased volume of glacier melt water is increasing the speed in which glaciers in the area are shrinking.

Moreover, the study, published in Nature Communications, revealed how melt water produces a distinct seasonal style of glacier stick-slip motion and showed that relatively small events occur every day during the summer, and during the winter there are larger multi-day events related to warmer days. As a result, for the first time, the team have been able to relate these processes to till sedimentology.

These findings demonstrate how small changes in melting, driven by air temperature rises, have a significant effect on a glacier’s behaviour. They also show that during winter, contrary to expectations, they are very active.

The study’s findings have important implications because unconsolidated beds underlie many of the fast flowing ice streams of modern day Antarctic as well as the Quaternary ice sheets.

Jane Hart, Professor in Geography at the University of Southampton and lead author of the study, said: “All glaciers are retreating which is effecting sea level rises and glacier melt water can accelerate the retreat. It’s virtually impossible to get inside one, therefore we have designed probes which were put into them and we were able to retrieve live date for the first time.

“Glaciers all over the world are retreating, but the rate they do so is dependent on numerous factors. Those in Iceland are retreating at different rates and both have rapidly growing lakes, which threaten to cover the whole glacier front, and affect their stability.

“As part of this latest study we hope to determine what is controlling their velocity, the rate of lake growth and how this growth is affecting ice retreat as we continue to contribute fundamental research in glaciology and wireless sensor networks.”

The team are now developing new technologies to investigate a series of other glaciers resting on unconsolidated sediments from both Iceland and elsewhere. This includes the first web connected GPS system. Initial results show that they are also responding to changes in melt during both summer and winter.

Glacsweb aims to use technological advances to understand what happens beneath glaciers and how they are affected by climate.

Kirk Martinez, Professor in Electronics and Computer Science at the University of Southampton, added: “An important challenge today is to understand climate change and its effect on sea level rise. Glaciers are a key element, but their behaviour is poorly understood. The melting of West Antarctica’s ice is not only controlled by snow fall and surface melting but also by processes under the ice.

“This research gave us a lot of exciting technical challenges and it is great to see that the data it produced is so useful to earth science. The emergence of small, low cost accurate GPS units has allowed us to put together a solar powered system which measures ice position and sends the data quickly and efficiently.”

Source: University of Southampton [April 29, 2019]



The last chance for Madagascar’s biodiversity

Scientists from around the world have joined together to identify the most important actions needed by Madagascar’s new government to prevent species and habitats being lost for ever.

The last chance for Madagascar's biodiversity
Many of Madagascar’s iconic lemur species such as this black and white ruffed lemur
are critically endangered [Credit: Daniel Burgas]

In January, Madagascar’s recently-elected president, Andry Rajoelina, began his five-year term of office. A group of scientists from Madagascar, the UK, Australia, the USA and Finland have published a paper recommending actions needed by the new government to turn around the precipitous decline of biodiversity and help put Madagascar on a trajectory towards sustainable growth.

Professor Jonah Ratsimbazafy, from the University of Antananarivo and one of the paper’s co-authors said: «The United States have the Statue of Liberty, France has the Eifel tower…. For us in Madagascar it is our biodiversity (the product of millions of years of evolution), which is the unique heritage we are known for around the world. We cannot let these natural wonders, including 100 different types of lemur found nowhere else, disappear».

The group say that Madagascar’s protected areas, some of the most important for biodiversity in the world, have suffered terribly in recent years from illegal mining, logging, and collection of threatened species for the pet trade. They suggest that much of this illegal activity is linked to corruption. They emphasise that the insecurity which goes alongside this illegal exploitation is bad for people as well as nature.

Dr Herizo Andrianandrasana, the first Malagasy DPhil graduate in Oxford University’s 800-year history and an experienced Malagasy conservationist, commented: «the destruction of Madagascar’s biodiversity benefits few; those who profit from rosewood trafficking, illegal mining in protected areas, or the prohibited trade in species like our Critically Endangered tortoises. However, the costs are widespread and affect all Malagasy.»

The last chance for Madagascar's biodiversity
Illegal logging in protected areas in Madagascar has damaged these globally important sites
[Credit: Toby Smith]

The group has identified five priority measures for the new government’s focus: investing in protected areas, strengthening local people’s tenure over natural resources, ensuring new infrastructure development limits impacts on biodiversity, tackling environmental crime linked to corruption, and investing in major restoration efforts that will address the country’s growing fuelwood crisis.

The team takes great care to emphasise that conservation must benefit, not harm, local communities.

Professor Julia Jones of Bangor University, who led the study said «Madagascar is one of the poorest countries on the planet. More than 40% of children under five are stunted due to malnutrition, and the country has more people living in extreme poverty than almost anywhere else on Earth. Conservation therefore needs to contribute to, and not detract from, national efforts targeting economic development. It must not make situations worse for the rural poor who are so often marginalised in decision making.»

The team believe that action in the five areas could make all the difference. Professor Ratsimbazafy again: «The time has come for action-It’s not too late to turn things around in Madagascar, but it soon will be.»

The last chance for Madagascar's biodiversity
Large scale clearance of Madagascar’s dry forests (to clear land for peanuts and corn)
is decimating remaining patches of this rare habitat, home to species found
nowhere on the planet [Credit: copyright Tahina Roland Frederic]

Professor Jones added: «Since his election President Rajoelina has given positive indications that he recognises the importance of Madagascar’s biodiversity. We will make sure that he has a copy of this paper and that the contents are well shared within Madagascar (and with the potential donors whose support will be needed). Our co-authors, and the many other active Malagasy and international scientists who care about Madagascar, are all ready to help the new president ensure that his term can deliver the turning point needed for Madagascar, and its wildlife.»

The paper is published in Nature Sustainability.

Source: Bangor University [April 29, 2019]



Climate, grasses and teeth: the evolution of South America mammals

Grass-eating mammals, including armadillos as big as Volkswagens, became more diverse in South America about 6 million years ago because shifts in atmospheric circulation drove changes in climate and vegetation, according to a University of Arizona-led research team.

Climate, grasses and teeth: the evolution of South America mammals
Barbara Carrapa, a University of Arizona professor of geosciences, takes rock samples at 14,000 feet (4267 m)
on Cerro Penitentes in the Cordillera Central of Argentina. The snow-capped mountain in the distance
 is Mt. Aconcagua in Argentina [Credit: Peter DeCelles, University of Arizona]

Geoscientists already knew the Earth was cooling 7 to 5.5 million years ago, a period of time known as the Late Miocene.

However, the changes in ocean climate during that time have been better understood than changes in the continental climate, said lead author Barbara Carrapa, professor and head of the UA department of geosciences.

The new research shows that about 7 to 6 million years ago, the global tropical atmospheric circulation known as the Hadley circulation intensified. As a result, the climate of South America became drier, subtropical grasslands expanded and the numbers of mammal species that were good at eating grasses increased.

Carrapa and her colleagues used a computer model to figure out that the Hadley circulation had strengthened in the late Miocene, altering the climate. They then compared the model’s predictions of the past climate with the natural archives of rainfall and vegetation stored in ancient soils. The model’s predictions agreed with the natural archives.

«We found a strong correlation between this big change in late Miocene climate and circulation that affected the ecology — the plants and animals,» she said. «It has implications for ecosystem evolution.»

Carrapa said the new research — an unusual blend of mammalian paleontology, the geochemistry of ancient soils and global climate computer models — provides a new understanding of the late Miocene, a time when near-modern ecosystems became established.

Geoscientists use the geochemistry of ancient soils, specifically forms of the elements oxygen and carbon, to infer past precipitation and vegetation. Researchers had thought the precipitation at the time the soil formed was mostly a function of the site’s topography and elevation.

Carrapa wanted to test that idea by looking at the geochemistry of ancient soils on a continental scale. She teamed up with her long-time colleague Clementz, a paleontologist.

The researchers compiled the published data of the oxygen-18/oxygen-16 ratio and carbon-13/carbon-12 ratio from ancient soils covering a wide swath of South America — from 15 degrees South latitude to 35 degrees South latitude, or about the change from La Paz, Bolivia to Buenos Aires, Argentina. Changes in the oxygen ratio provide information on past precipitation, while changes in carbon ratio indicate what plants were growing at the time.

Clementz scoured the published literature and did what Carrapa called «… an amazing job of pulling all the data together so we could look at it in a comprehensive way.»

The results were surprising, Carrapa said. The changes in soil geochemistry during the late Miocene changed in latitudinal bands from north to south, indicating an underlying cause spanning much of South America, not just local changes in elevation or topography.

The two researchers thought the systematic shifts in soil geochemistry were related to changes in climate, so they asked Feng to help them by applying the global climate model she used for research.

Feng loaded known information about the Miocene-to-late-Miocene climate, including atmospheric carbon dioxide concentrations and the ocean temperatures, into the computer model and then asked it to simulate three different versions of late Miocene climate — not much cooler, cooler, and much cooler than before. In each case, the simulation indicated what soil geochemistry would have occurred under that climate regime.

The team found the geochemistry of South American ancient soils predicted by the model matches the geochemistry of the actual soil samples.

Feng figured out that the Earth’s Hadley circulation intensified from 7 to 6 million years ago.

«The records compiled by Barbara and Mark could be explained by a significant change in the strength of the Hadley circulation,» she said.

Feng’s work with the global climate model shows how the past climate could have created the patterns the team was seeing in the soil geochemistry, Clementz said.

The carbon ratio from the ancient soils reflects the vegetation of the time and indicates that in the late Miocene, grasslands were expanding as the climate was changing.

«During the late Miocene, things are starting to dry out, particularly in the 25-30 degree South zone,» he said. «There’s also an increase in the numbers of animals with high-crowned or ever-growing teeth.»

Grasses contain silica, an abrasive substance, which is why grass-eaters have either high-crowned teeth or teeth that continue to grow. The mammals that became more prevalent in the late Miocene included giant armadillos and rhinoceros-like animals and also smaller mammals, he said.

Carrapa said, «Looking at geological pasts is like looking at different planets. The state of the Earth we see today is very different from the Earth of 10 million years ago, 6 million years ago — it’s a different planet. You have the possibility of looking at a different planet through the lens of time, and with the geological record we can do that.»

The paper has been published in the Proceedings of the National Academy of Sciences.

Source: University of Arizona [April 29, 2019]



Details of the history of inner Eurasia revealed by new study

An international team of researchers has combined archaeological, historical and linguistic data with genetic information from over 700 newly analyzed individuals to construct a more detailed picture of the history of inner Eurasia than ever before available. In a study published in Nature Ecology & Evolution, they found that the indigenous populations of inner Eurasia are very diverse in their genes, culture and languages, but divide into three groups that stretch across the area in east-west geographic bands.

Details of the history of inner Eurasia revealed by new study
Children from one of the Tajikistan communities included in the study
[Credit: Elena Balanovska]

Inner Eurasia, including areas of modern-day Armenia, Georgia, Kazakhstan, Moldova, Mongolia, Russia, Tajikistan, Ukraine and Uzbekistan, was once the cross-roads connecting Asia and Europe, and a major intersection for the exchange of culture, trade goods and genes in prehistory and historical periods, including the era of the famous Silk Road.

This vast area can also be divided into several distinct ecological regions that stretch in largely east-west bands across Inner Eurasia, consisting of the deserts at the southern edge of the region, the steppe in the central part, taiga forests further north, and tundra towards the Arctic region. The subsistence strategies used by indigenous groups in these regions largely correlate with the ecological zones, for example reindeer herding and hunting in the tundra region and nomadic pastoralism on the steppe.

Despite the long and important history of inner Eurasia, details about past migrations and interactions between groups are not always clear, especially in prehistory. «Inner Eurasia is a perfect place to investigate the relationship between environmental conditions and the pattern of human migration and mixture, as well as changes driven by cultural innovations such as the introduction of dairy pastoralism into the steppe,» states Choongwon Jeong of the Max Planck Institute for the Science of Human History, co-first and senior author of the paper.

In order to clarify our understanding of some of the nuances of the history of the region, an international team of researchers undertook an ambitious project to use modern and ancient DNA from a broad geographic range and time period, in concert with archaeological, linguistic and historical information, to clarify the relationships between the different populations. «A few ethnic groups were studied previously,» comments Oleg Balanovsky from the Vavilov Institute of General Genetics in Moscow, also co-first author, «but we conducted more than a hundred field trips to study this vast region systematically, and reached communities speaking almost all of the Inner Eurasian languages».

Three distinct east-west groupings

For this study, the researchers analyzed DNA from 763 individuals from across the region as well as reanalyzed the genome-wide data from two ancient individuals from the Botai culture, and compared those results with previously published data from modern and ancient individuals. They found three distinct genetic groupings, which geographically are arranged in east-west bands stretching across the region and correlating generally to ecological zones, where populations within each band share a distinct combination of ancestries in varying proportions.

Details of the history of inner Eurasia revealed by new study
Geographic locations of the Eneolithic Botai, groups including newly sampled individuals, and nearby groups
with published data. The map is overlayed with ecoregional information, divided into 14 biomes
downloaded from ecoregions2017.appspot.com/ (credited to Ecoregions 2017 © Resolve)
[Credit: Jeong & Balanovsky et. al. 2019]

The northernmost grouping, which they term «forest-tundra», includes Russians, all Uralic language-speakers, which includes Hungarian, Finnish and Estonian, and Yeniseian-language speakers, of which only one remains today and is spoken in central Siberia. The middle grouping, which they term «steppe-forest», includes Turkic- and Mongolic-speaking populations from the Volga and the region around the Altai and Sayan mountains, near to where Russia, China, Mongolia and Kazakhstan meet. The southernmost grouping, «southern-steppe», includes the rest of Turkic- and Mongolic-speaking populations living further south, such as Kazakhs, Kyrgyzs and Uzbeks, as well as Indo-European-speaking Tajiks.

Previously unknown genetic connections revealed

Because the study includes data from a broad time period, it is able to show shifts in ancestry in the past that reveal previously unknown interactions. For example, the researchers found that the southern-steppe populations had a larger genetic component from West and South Asia than the other two groupings. This component is also widespread in the ancient populations of the region since the second half of the first millennium BC, but not found in Central Kazakhstan in earlier periods. This hints at a population movement from the southern-steppe region to the steppe-forest region that was previously unknown.

«Inner Eurasia has functioned as a conduit for human migration and cultural transfer since the first appearance of modern humans in this region. As a result, we observe deep sharing of genes between Western and Eastern Eurasian populations in multiple layers,» explains Jeong. «The opportunity to find direct evidence for the hidden old layers of admixture, which is often difficult to appreciate from present-day populations, is very exciting.»

«We found not only corridors, but also barriers for migrations,» adds Balanovsky. «Some of them separate the historical groups of populations, while others, like the distinct barrier following the Great Caucasus mountain ridge, were obviously shaped by the geographic landscape.»

Two ancient individuals resequenced in this study originated from the Botai culture in Kazakhstan where the horse was initially domesticated. Analysis of the Y-chromosome (inherited along the paternal genealogical lines) revealed a genetic lineage which is typical in the Kazakh steppe up to the present day. But analysis of the autosomes, which both parents contribute to their children, show no trace of Botai ancestry left in present-day people, likely due to repeated migrations into the region both from the west and the east since the Bronze Age.

The researchers emphasize that their model of three groupings does not perfectly explain all known populations and that there are examples of both outliers and intermediate groups. «It is important to organize a future study for further sampling of sparsely populated regions between the clines, for example, Central Kazakhstan or East Siberia,» states Johannes Krause, also of the Max Planck Institute for the Science of Human History, and senior author of the paper.

Source: Max Planck Institute for the Science of Human History [April 29, 2019]



Human ancestors were ‘grounded,’ new analysis shows

African apes adapted to living on the ground, a finding that indicates human evolved from an ancestor not limited to tree or other elevated habitats. The analysis adds a new chapter to evolution, shedding additional light on what preceded human bipedalism.

Human ancestors were 'grounded,' new analysis shows
An evolutionary tree depicting the relationships among living apes, Ardi, and modern humans. Each branch on the tree
represents a species and their intersections represent their common ancestors. The dots represent hypothetical evolutionary
changes associated with the evolution of ground-living adaptations in the common ancestor of African apes and humans
 as well as the evolution of bipedalism, which is supported by the analysis. This shows that human bipedalism
evolved from an ancestral form similar to the living African apes [Credit: Thomas Prang]

«Our unique form of human locomotion evolved from an ancestor that moved in similar ways to the living African apes—chimpanzees, bonobos, and gorillas,» explains Thomas Prang, a doctoral candidate in New York University’s Department of Anthropology and the author of the study, which appears in the journal eLife. «In other words, the common ancestor we share with chimpanzees and bonobos was an African ape that probably had adaptations to living on the ground in some form and frequency.»

The way that humans walk—striding bipedalism—is unique among all living mammals, an attribute resulting from myriad changes over time.

«The human body has been dramatically modified by evolutionary processes over the last several million years in ways that happened to make us better walkers and runners,» notes Prang.

Much of this change is evident in the human foot, which has evolved to be a propulsive organ, with a big toe incapable of ape-like grasping and a spring-like, energy-saving arch that runs from front to back.

These traits raise a long-studied, but not definitively answered, question: From what kind of ancestor did the human foot evolve?

In the eLife work, Prang, a researcher in NYU’s Center for the Study of Human Origins, focused on the fossil species Ardipithecus ramidus (‘Ardi’), a 4.4 million-years-old human ancestor from Ethiopia—more than a million years older than the well-known ‘Lucy’ fossil. Ardi’s bones were first publicly revealed in 2009 and have been the subject of debate since then.

In his research, Prang ascertained the relative length proportions of multiple bones in the primate foot skeleton to evaluate the relationship between species’ movement (locomotion) and their skeletal characteristics (morphology). In addition, drawing upon the Ardi fossils, he used statistical methods to reconstruct or estimate what the common ancestor of humans and chimpanzees might have looked like.

Here, he found that the African apes show a clear signal of being adapted to ground-living. The results also reveal that the Ardi foot and the estimated morphology of the human-chimpanzee last common ancestor is most similar to these African ape species.

«Therefore, humans evolved from an ancestor that had adaptations to living on the ground, perhaps not unlike those found in African apes,» Prang concludes. «These findings suggest that human bipedalism was derived from a form of locomotion similar to that of living African apes, which contrasts with the original interpretation of these fossils.»

The original interpretation of the Ardi foot fossils, published in 2009, suggested that its foot was more monkey-like than chimpanzee- or gorilla-like. The implication of this interpretation is that many of the features shared by living great apes (chimpanzees, bonobos, gorillas, and orangutans) in their foot and elsewhere must have evolved independently in each lineage—in a different time and place.

«Humans are part of the natural world and our locomotor adaptation—bipedalism—cannot be understood outside of its natural evolutionary context,» Prang observes. «Large-scale evolutionary changes do not seem to happen spontaneously. Instead, they are rooted in deeper histories revealed by the study of the fossil record.

«The study of the Ardi fossil shows that the evolution of our own ground-living adaptation—bipedalism—was preceded by a quadrupedal ground-living adaptation in the common ancestors that we share with the African apes.»

Source: New York University [April 30, 2019]



Middle Pleistocene human skull reveals variation and continuity in early Asian humans

A team of scientists led by LIU Wu and WU Xiujie from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences reported the first ever Middle Pleistocene human skull found in southeastern China, revealing the variation and continuity in early Asian humans.

Middle Pleistocene human skull reveals variation and continuity in early Asian humans
The Hualongdong Middle Pleistocene human skull and the collapsed cave site, with the fossil-bearing
breccia in beige aournd the limestone blocks [Credit: WU Xiujie & Erik Trinkaus]

Excavations in Middle Pleistocene cave deposits in southeastern China yielded a largely complete skull that exhibits morphological similarities to other East Asian Middle and Late Pleistocene archaic human remains, but also foreshadows later modern human forms.
Fossil evidence for human evolution in East Asia during the Pleistocene is often fragmentary and scattered, which makes evaluating the pattern of archaic human evolution and modern human emergence in the region complicated.

WU Xiujie and his colleagues reported the recent discovery of most of a skull and associated remains dating to around 300,000 years ago in Hualong Cave (Hualongdong). The features of the Hualongdong fossils complement those of other East Asian remains in indicating a continuity of form through the Middle Pleistocene and into the Late Pleistocene.

Middle Pleistocene human skull reveals variation and continuity in early Asian humans
The virtual reconstruction of the Hualongdong 6 human skull, with mirror-imaged portions in gray,
plus two of the few stone tools from the site [Credit: WU Xiujie]

In particular, the skull features a low and wide braincase with a projecting brow but a less prominent midface, as well as an incipient chin. The teeth are simple in form, contrasting with other archaic East Asian fossils, and its third molar is either reduced in size or absent.
According to the authors, the remains not only add to the expected variation of these Middle Pleistocene humans, recombining features present in other individuals from the same time period, but also foreshadow developments in modern humans, providing evidence for regional continuity.

The findings were published in Proceedings of the National Academy of Sciences.

Source: Chinese Academy of Sciences [April 30, 2019]



Scientists Planning Now for Asteroid Flyby a Decade Away

Asteroid Watch logo.

April 30, 2019

On April 13, 2029, a speck of light will streak across the sky, getting brighter and faster. At one point it will travel more than the width of the full Moon within a minute and it will get as bright as the stars in the Little Dipper. But it won’t be a satellite or an airplane — it will be a 1,100-foot-wide (340-meter-wide) near-Earth asteroid called 99942 Apophis that will cruise harmlessly by Earth, about 19,000 miles (31,000 kilometers) above the surface. That’s within the distance that some of our spacecraft that orbit Earth.

Animation above: This animation shows the distance between the Apophis asteroid and Earth at the time of the asteroid’s closest approach. The blue dots are the many man-made satellites that orbit our planet, and the pink represents the International Space Station. Animation Credits: NASA/JPL-Caltech.

The international asteroid research community couldn’t be more excited.

This week at the 2019 Planetary Defense Conference in College Park, Maryland, scientists are gathering to discuss observation plans and science opportunities for the celestial event still a decade away. During a session on April 30, scientists will discuss everything from how to observe the event to hypothetical missions we could send out to the asteroid.

«The Apophis close approach in 2029 will be an incredible opportunity for science,» said Marina Brozovi?, a radar scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, who works on radar observations of near-Earth objects (NEOs). «We’ll observe the asteroid with both optical and radar telescopes. With radar observations, we might be able to see surface details that are only a few meters in size.»

It’s rare for an asteroid of this size to pass by Earth so close. Although scientists have spotted small asteroids, on the order of 5-10 meters, flying by Earth at a similar distance, asteroids the size of Apophis are far fewer in number and so do not pass this close to Earth as often.

Image above: Nine new radar images of near-Earth asteroid 2007 PA8 were obtained between Oct. 31 and Nov. 13, 2012. Image Credits: NASA/JPL-CalTech.

The asteroid, looking like a moving star-like point of light, will first become visible to the naked eye in the night sky over the Southern Hemisphere, flying above Earth from the east coast to the west coast of Australia. It will be mid-morning on the East Coast of the United States when Apophis is above Australia. It will then cross the Indian Ocean, and by the afternoon in the eastern U.S. it will have crossed the equator, still moving west, above Africa. At closest approach, just before 6 p.m. EDT, Apophis will be over the Atlantic Ocean — and it will move so fast that it will cross the Atlantic in just an hour. By 7 p.m. EDT, the asteroid will have crossed over the United States.

A team of astronomers at the Kitt Peak National Observatory discovered Apophis in June 2004. The astronomers were only able to detect the asteroid for two days before technical and weather issues prevented further observations. Luckily, another team rediscovered the asteroid at the Siding Spring Survey in Australia later that year. The observations caused quite a stir — initial orbital calculations revealed that the asteroid had a 2.7% chance of impacting Earth in 2029. Fortunately, additional observations completely ruled out that possibility.

Since its discovery, optical and radar telescopes have tracked Apophis as it continues on its orbit around the Sun, so we know its future trajectory quite well. Current calculations show that Apophis still has a small chance of impacting Earth, less than 1 in 100,000 many decades from now, but future measurements of its position can be expected to rule out any possible impacts.

The most important observations of Apophis will occur in 2029, when asteroid scientists around the world will have an opportunity to conduct a close-up study of the Apophis’ size, shape, composition and possibly even its interior.

Near Earth Asteroids. Image Credit: ESA

At the conference, scientists will discuss questions like «How will Earth’s gravity affect the asteroid as it passes by?,» «Can we use Apophis’ flyby to learn about an asteroid’s interior?» and «Should we send a spacecraft mission to Apophis?»

«We already know that the close encounter with Earth will change Apophis’ orbit, but our models also show the close approach could change the way this asteroid spins, and it is possible that there will be some surface changes, like small avalanches,» said Davide Farnocchia, an astronomer at JPL’s Center for Near Earth Objects Studies (CNEOS), who is co-chairing the April 30 session on Apophis with Brozovi?.

«Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs),» said Paul Chodas, director of CNEOS. «By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense.»

Related article:

NASA Rules Out Earth Impact in 2036 for Asteroid Apophis

Related links:

2019 Planetary Defense Conference: http://pdc.iaaweb.org/

For more information about asteroids and near-Earth objects, visit: http://www.jpl.nasa.gov/asteroidwatch Updates about near-Earth objects are also available by following AsteroidWatch on Twitter at http://www.twitter.com/asteroidwatch .

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/JPL/DC Agle.

Greetings, Orbiter.chArchive link

Space Research Continues on Station as NASA, SpaceX Move Off May 1 Launch

ISS — Expedition 59 Mission patch.

April 30, 2019

NASA has requested SpaceX move off from May 1 for the launch of the company’s 17th commercial resupply mission to the International Space Station.

On April 29, the space station team identified an issue with one of the station’s Main Bus Switching Units that distributes power to two of the eight power channels on the station.  There are no immediate concerns for the crew or the station. Teams are working on a plan to robotically replace the failed unit and restore full power to the station system. Additional information will be provided as it becomes available. The earliest possible launch opportunity is no earlier than Friday, May 3.

Image above: The Gulf of Mexico, Galveston Bay and Houston, Texas, the home of NASA’s Johnson Space Center, are pictured from the International Space Station 256 miles above the Lone Star State. Image Credit: NASA.

Meanwhile, the Expedition 59 crew explored a wide variety of microgravity science today including human research, robotics and space manufacturing techniques.

Flight Engineer David Saint-Jacques jotted down his impressions of space life in a private journal this morning for the Behavioral Core Measures study. Later he installed new incubator hardware inside the Space Automated Bioproduct Lab for the Kidney Cells experiment that seeks innovative treatments for humans on Earth and in space.

Image above: The International Space Station was pictured by an Expedition 56 crewmember aboard a departing Soyuz crew ship on Oct. 4, 2018. Image Credit: NASA.

Astrobee, a new free-flying robotic assistant, is being readied for testing today inside Japan’s Kibo lab module. NASA astronaut Anne McClain inspected and checked out the cube-shaped mini-robot’s components then activated the device to perform a flyaround. Astrobee could save the crew time performing routine maintenance duties and providing additional lab monitoring capabilities.

Engineers are also testing the feasibility of producing fiber optic cable in space. Microgravity reveals physical processes hidden by Earth’s gravity that may prove the superiority of space manufacturing. Flight Engineer Christina Koch contributed to that study today working on fiber samples in the Microgravity Science Glovebox that will be examined back on Earth for quality.

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

SpaceX: http://www.nasa.gov/spacex

NASA: http://www.nasa.gov/

Behavioral Core Measures: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7537

Space Automated Bioproduct Lab: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1148

Fiber optic cable in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7630

Microgravity Science Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=341

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

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

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Hundreds of dead dolphins wash up on French coast

A record number of dead dolphins have washed up on France’s Atlantic coast in recent months after being caught in fishing nets, the Pelagis observatory said Thursday.

Hundreds of dead dolphins wash up on French coast
Dead dolphins on a shore of La Tranche sur Mer, on the Atlantic coast, western France
[Credit: Cecile Dars, Observatoire Pelagis, CNRS, Universite de la Rochelle]

«We’ve had around 1,200 small cetaceans along the coast» of the Bay of Biscay, of which more than 90 percent were common dolphins, biologist Olivier Van Canneyt told AFP.
The observatory he works for said the number of dead dolphins had set a record each year since 2017, and warned that the species could be wiped out in the area.

«There were two peaks in mid-February and mid-March linked to currents that are stronger at that time owing to low-pressure conditions,» noted Van Canneyt, a specialist in sea mammels and birds.

Hundreds of dead dolphins wash up on French coast
Each year since 2017, a record number of dead dolphins have washed up on France’s Atlantic coast
 between January and April, the Pelagis observatory says [Credit: Loic Venance/AFP]

The observatory said that around 85 perecent of the dolphin carcasses that could be examined bore traces of accidental capture, while noting that almost three times as many dead dolphins had likely not even reached the coast.

Dolphins and porpoises can be caught in fishing nets and suffocated when they hunt for sea bass and whiting at the same time as fishing fleets, especially during winter months in the region.

The number of dolphins that wash up on the coast has increased this year despite efforts by the observatory to warn the mammals of a human presence by using acoustic «pingers».

Environment Minister Francois de Rugy said in March that he would unveil a plan to limit such deaths «by the end of the year».

Source: AFP [April 25, 2019]



2019 April 30 Meteor Misses Galaxy Image Credit: Aman…

2019 April 30

Meteor Misses Galaxy
Image Credit: Aman Chokshi

Explanation: The galaxy was never in danger. For one thing, the Triangulum galaxy (M33), pictured, is much bigger than the tiny grain of rock at the head of the meteor. For another, the galaxy is much farther away – in this instance 3 million light years as opposed to only about 0.0003 light seconds. Even so, the meteor’s path took it angularly below the galaxy. Also the wind high in Earth’s atmosphere blew the meteor’s glowing evaporative molecule train away from the galaxy, in angular projection. Still, the astrophotographer was quite lucky to capture both a meteor and a galaxy in a single exposure – which was subsequently added to two other images of M33 to bring up the spiral galaxy’s colors. At the end, the meteor was gone in a second, but the galaxy will last billions of years.

∞ Source: apod.nasa.gov/apod/ap190430.html

Viewing the eta Aquariid Meteor Shower in 2019

The 2013 Eta Aquarid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, ‘Composite of approximately 50 images containing 26 meteors, meteor train, 17 % moon, zodiacal light and Pilbara desert.
The 2013 Eta Aquarid meteor shower was fantastic as viewed from Earth’s Southern Hemisphere. Colin Legg of Australia created this composite of his experience. He wrote, ‘Composite of approximately 50 images containing 26 meteors, meteor train, 17 % moon, zodiacal light and Pilbara desert.
 © Colin Legg, 2013, Australia

The eta Aquariids (ETA) are active between April 17 and May 24. The strongest activity is usually seen near May 7, when rates can reach 25-30 meteors per hour as seen from the tropical areas of the Earth. Unlike most major annual meteor showers, there is no sharp peak for this shower, but rather a plateau of good rates that last approximately one week centered on May 7. The eta Aquariids are particles from Halley’s Comet, which last passed through the inner solar system in 1986. The meteors we currently see as members of the eta Aquariid shower separated from Halley’s Comet hundreds of years ago. The current orbit of Halley’s Comet does not pass close enough to the Earth to be a source of meteoric activity.

The eta Aquariids are only visible during the last couple of hours before the start of morning twilight. The reason for this is that the radiant (the area of the sky where these meteors appear to shoot from) is situated approximately 60 degrees west of the sun. Therefore it rises before the sun in the morning hours. The time of radiant rise is between 2:00 and 3:00 local daylight saving time (DST), depending on your longitude. The real key is the latitude. There is an observing window for this shower between the time the radiant rises and the beginning of morning nautical twilight. This window ranges from zero at 60 degrees north latitude to all night in Antarctica. Unfortunately in Antarctica, the radiant never rises very high in the sky and most of the activity is not visible from there. The best combination of a large observing window and a decent radiant altitude occurs between the equator and 30 degrees south latitude. From this area the radiant reaches a maximum altitude of 50 degrees at nautical twilight. The observing window ranges from 3.5 hours at the equator to slightly over 4.0 hours at 30 degrees south latitude. Going further south will increase your observing window but the maximum altitude will begin to fall closer to the horizon.

Since most meteor observers live in the northern hemisphere, here are the conditions at several different latitudes: the observing window for 50N is 1.5 hours with a radiant altitude of 15 degrees. The observing window for 40N is 2.25 hours with a radiant altitude of 25 degrees. The observing window for 30N is 2.75 hours with a radiant altitude of 35 degrees.

Aquarius constellation
Aquarius constellation – “Peace sign”

Near maximum, the radiant may be easily spotted as it lies near the “water jar” in Aquarius. This “Y” shaped pattern of stars is also known as the “peace sign” to some observers. It should be noted that very few meteors are actually seen at the radiant. This position just happens to be the apparent source of the activity. More activity is seen further up in the sky where longer shower members can be seen. That is why it is advised to look half-way up in the sky. Do not look straight up as this is the direction of least meteoric activity. By looking at the zenith you are looking though the thinnest slice of atmosphere possible. This is great for lunar and planetary viewing but not for meteor observing. Have the horizon be at the bottom of your field of view and your center will lie near the optimal forty-five degree altitude zone.

The conditions for viewing the eta Aquariids in 2019 are close to perfect. A new moon will occur on May 4, only a few days before maximum activity. The moon will not start to interfere with viewing these meteors until May 13, when it sets shortly after the radiant rises in the opposite side of the sky.

To best see these meteors you should start viewing near the time the radiant rises. This is between 2:00 and 3:00am for most observers situated at mid-northern latitudes. It would be best to view toward the eastern half of the sky with the radiant in the lower portion of your field of view. This way you can see these meteors shooting in all directions out of the radiant, even downwards. This suggestion is good for all observers no matter your location. These meteors will shoot in all directions, especially low in the northeast and southeastern sky. The best ones will shoot straight upwards through the center of your field of view. The eta Aquariids are swift meteors leaving a high percentage of persistent trains. Unlike the Geminids and Perseids, fireballs from this source are rare.

The graphs below show eta Aquariid and sporadic activity from 2007-2017. Each dot represents a single hourly rate reported by a single observer, corrected for effective time, obstructions, sky conditions, and zenith angle. Reported sporadic rates are also plotted for reference (also corrected for effective time, obstructions, and sky conditions). Each plot is in terms of Solar Longitude, not date, allowing direct comparison between years. The expected maximum for the eta Aquariids each year lies at solar longitude 46.2 Due to the usually low zenith angle of this shower, there is a large amount of data scatter and a broad, ill-defined peak even in a good year without lunar interference.

The graphs are courtesy of James Richardson using data from the International Meteor Organization (IMO). It should be noted that the corrected rate values do not represent rates that anyone will actually see, but are simply a way of combining raw meteor hourly rates from multiple observers in various locations and observing under disparate conditions. The corrected raw data does a good job of showing the ramp up and ramp down of each shower as they occur/occurred, where the actual ZHR will be roughly in the *middle* of the plotted numbers (that is, don’t follow the top of the plot, watch the middle of the plot). Also note that the vertical scale is logarithmic, such that a typical shower will generally ramp up and down in ‘saw tooth’ fashion, forming a triangular peak (sometimes with asymmetrical sides).

Meteor shower rates, as seen by an individual observer, are quite random (following a Poisson distribution), more random than most people intuitively expect, such that wide variations from one hour to the next can occur, or wide variations between two observers at two different locations in the same hour. The plots also point to the importance of observer accuracy in reporting their observations: times, counts, limiting magnitude, sky obscuration, shower member identification. I think it is elucidating for observers to see their raw and minimally corrected (normalized) rates directly, rather than as a averaged, single value with error bars.


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‘The Sanctuary’ Prehistoric Timber Circle site, Wiltshire, 21.4.19.

‘The Sanctuary’ Prehistoric Timber Circle site, Wiltshire, 21.4.19.

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Scientists get to the bottom of a ‘spitting’ black hole

ESA — Integral Mission patch.

29 April 2019

Data from ESA’s Integral high-energy observatory have helped shed light on the workings of a mysterious black hole found spitting out ‘bullets’ of plasma while rotating through space.

The black hole is part of a binary system known as V404 Cygni and is sucking in material from a companion star. It is located in our Milky Way, some 8000 light-years away from Earth, and was first identified in 1989, when it caused a huge outburst of high-energy radiation and material.

Black hole spitting out ‘bullets’ of plasma

After 26 years of dormancy, it woke up again in 2015, becoming for a short period of time the brightest object in the sky observable in high-energy X-rays.

Astronomers from all over the world pointed their ground and space-based telescopes towards the celestial object, and discovered that the black hole was behaving somewhat strangely.

A new study, based on data collected during the 2015 outburst, has now revealed the inner workings of this cosmic monster. The results are reported today in the journal Nature.

“During the outburst we observed details of the jet emissions when material is ejected at a very high speed from the vicinity of the black hole,” says Simone Migliari, an astrophysicist at ESA who is a co-author on the paper.

“We can see the jets shooting out in different directions on a timescale of less than an hour, which means that the inner regions of the system are rotating quite fast.”

Usually astronomers see the jets shooting straight out from the poles of black holes, perpendicular to the surrounding disc of material that is accreted from the companion star.

Black hole and companion star

Previously, there had only been one black hole observed with a rotating jet. It was, however, rotating much slower, completing one cycle in about six months.

The astronomers could observe the V404 Cygni jets in radio waves using telescopes like those of the Very Long Baseline Array in the US.

Meanwhile, high-energy X-ray data from Integral and other space observatories helped them decode what was happening at the same time inside the inner region of the 10 million kilometre-wide accretion disc. This was important since it is the mechanics of the disc that causes the jet’s strange behaviour.

“What’s different in V404 Cygni is that we think the disc of material and the black hole are misaligned,” says Associate Professor James Miller-Jones, from the International Centre for Radio Astronomy Research (ICRAR) at Curtin University, Australia, who is the lead author of the new paper.

“This appears to be causing the inner part of the disc to wobble like a spinning top that is slowing down, and fire jets out in different directions as it changes orientation.”

Tilted accretion disc

During the outburst, a large amount of the surrounding material was falling into the black hole at once, temporarily increasing the accretion rate of disc material towards the black hole and resulting in a sudden surge of energy. This was seen by Integral as an abrupt increase of the X-ray emission.

Integral’s observations were used to estimate the energy and geometry of the accretion onto the black hole, which in turn were crucial to understand the link between the incoming and outflowing material to create a complete picture of the situation.

“With Integral, we were able to keep looking at V404 Cygni continuously for four weeks, while other high-energy satellites could only take shorter snapshots,” says Erik Kuulkers, Integral Project Scientist at ESA.

Integral high-energy observatory

“The X-ray data support a model where the inner part of the accretion disc is tilted with respect to the rest of the system, most likely due to the spin of the black hole being inclined with respect to the orbit of the companion star,” explains Simone.

Scientists have been studying what caused this strange misalignment. One possibility is that the black hole spin axis may have been tilted by the ‘kick’ received during the supernova explosion that created it.

“The results would fit in a scenario, also studied in recent computer simulations, where the accretion flow in the vicinity of the black hole and the jets can rotate together,” says Erik.

“We should expect similar dynamics in any strongly-accreting black hole whose spin is misaligned with the inflowing gas, and we will have to take into account varying jet inclination angles when interpreting observations of black holes across the Universe.”

Notes for editors

“A rapidly-changing jet orientation in the stellar-mass black hole V404 Cygni” by J. C. A. Miller-Jones et al is published in Nature: https://www.nature.com/articles/s41586-019-1152-0

Integral, the International Gamma-ray Astrophysics Laboratory, was launched on 17 October 2002. It is an ESA project with instruments and a science data centre funded by ESA Member States (especially the Principal Investigator countries: Denmark, France, Germany, Italy, Spain and Switzerland), and with the participation of Russia and the USA. The mission is dedicated to spectroscopy and imaging of celestial gamma-ray sources in the energy range 15 keV to 10 MeV with concurrent source monitoring in X-ray (3–35 keV) and optical (V-band, 550 nm) wavelengths.

Integral: http://sci.esa.int/integral/

Images, Text, Credits: ESA/Markus Bauer/Erik Kuulkers/Simone Migliari/International Centre for Radio Astronomy Research (ICRAR)/Pete Wheeler/James Miller-Jones.

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A Clean Look Like the body’s long-suffering housekeeper, the…

A Clean Look

Like the body’s long-suffering housekeeper, the kidneys endlessly clean up our internal mess. Sifting through our blood, they filter out unwanted waste before returning vital nutrients via specialised structures called proximal tubules. These tubules are essential to good health, and serious illnesses can result from any malfunction, but there’s much we don’t we know about them. To spare human or animal participants, researchers increasingly turn to artificial recreations of biological situations for their investigations. Producing realistic kidney components in a lab isn’t straightforward however, and previous attempts have lacked the 3D structure of real kidneys. A new approach allows researchers to 3D-print proximal tubules (stained green) alongside blood vessels (red), and directly observe the reabsorption process in real time. Initial studies have already investigated the effects of hyperglycaemia, a condition associated with diabetes, suggesting the tool could help us get a clear look at one the body’s most crucial components.

Written by Anthony Lewis

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Space Station Science Highlights: Week of April 22, 2019

ISS — Expedition 59 Mission patch.

April 29, 2019

Astronauts aboard the International Space Station installed a variety of hardware and set up science experiments that arrived via a Cygnus resupply ship last week. Crew members also collected samples for investigations.

Here are details on some of the scientific activities the Expedition 59 crew members conducted the week of April 22:

Testing the Response of New Materials to the Space Environment

Image above: NASA astronauts Anne McClain and Nick Hague install cartridges into the Materials ISS Experiment Flight Facility (MISSE-FF) in the JEM Airlock. Alpha Space’s facility provides a unique platform that is available for the private sector, as well as other government entities, to conduct applied materials testing or technical demonstrations. Image Credit: NASA.

The Materials ISS Experiment Flight Facility (MISSE-FF) platform provides the ability to test materials, coatings, and components or other larger experiments in the harsh environment of space, which is virtually impossible to do on Earth. Testing in low-Earth orbit (LEO) allows investigators to determine how materials react to exposure to ultraviolet radiation (UV), atomic oxygen (AO), ionizing radiation, ultrahigh vacuum (UHV), charged particles, thermal cycles, electromagnetic radiation, and micro-meteoroids in the LEO environment. Crewmembers installed three new MISSE Sample Containers (MSCs) onto the MISSE Transfer Tray (MTT) in the Japanese Equipment Module (JEM) airlock for robotic attachment to the MISSE-FF facility on the outside of the space station.

Image above: Flying over North Atlantic Ocean, seen by EarthCam on ISS, speed: 27’664 Km/h, altitude: 405,64 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam’s from ISS on April 29, 2019 at 11:29 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

Investigating microbe adaptation to microgravity

The Experimental Evolution of Bacillus subtilis Populations in Space: MVP-02 investigation seeks to understand how organisms adapt to the space environment, an important component of future space exploration. Microbes may play fundamental roles in the development of biologically-based closed-loop regenerative life support, in-situ resource utilization, and have extensive interactions with human and plant hosts. Further, microbes may pose challenges through virulence and contamination and as nuisance factors such as biofilms in water supply and ventilation systems.  Last week, the crew installed the MVP-02 platform onto Express Rack 4 and took documentation photos.

Manufacturing fiber optic cable in microgravity

Image above: Canadian Space Agency astronaut David Saint-Jacques shown in front of the Space Fibers facility. Space Fibers evaluates methods and materials for producing fiber optic cable in microgravity, producing improved quality fiber over what can be manufactured on the ground. Image Credit: NASA.

The crew also installed a sample cartridge into the Space Fibers facility for a run initiated by the ground team. Space Fibers evaluates a method for producing fiber optic cable from a blend of zirconium, barium, lanthanum, sodium and aluminum, called ZBLAN, in space. ZBLAN glass, theoretically one hundred times more transparent than silica-based glass, is exceptional for fiber optics. However, when it is produced on Earth, imperfections degrade its performance. Microgravity suppresses two mechanisms that commonly degrade this fiber, and previous studies showed improved properties in ZBLAN fiber drawn in microgravity compared to that fabricated on the ground.

Other investigations on which the crew performed work:

— Rodent Research-12 (RR-12) examines the effects of spaceflight on the function of antibody production and immune memory using a mouse model: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7868

Image above: SS crew member installs an Experiment Cube in the International Commercial Experiment Cubes (ICE Cube) facility. This facility offers flexibility to host many different experiments for research, technology demonstration or educational objectives. Image Credit: NASA.

— International Commercial Experiment Cubes (ICE Cubes): The crew installed Experiment Cubes in the ICE Cube facility, is an experiment platform that offers flexibility to host many different experiments for research, technology demonstration or educational objectives: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7607

— The SUBSA investigation crystallizes melts in microgravity to improve understanding of solidification phenomena and crystal production: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=308

— Fluid Shifts characterizes fluid redistribution and compartmentalization in the body associated with long-duration space flight and correlates these findings with vision changes and other elements of the Spaceflight Associated Neuro-ocular (SANS) syndrome.  Understanding effects of these changes helps prepare for long duration missions such as the planned journey to Mars: https://www.nasa.gov/content/fluid-shifts-study-advances-journey-to-mars

— Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

— RADI-N2, a Canadian Space Agency investigation, characterizes the ISS neutron environment and the risk posed to the crew members’ health in order to develop advanced protective measures for future spaceflight. Bubble detectors used in this investigation are designed detect neutrons and ignore other radiation: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=874

Space to Ground: Extreme Exposure: 04/26/2019

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

Materials ISS Experiment Flight Facility (MISSE-FF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7515

Experimental Evolution of Bacillus subtilis Populations in Space (MVP-02): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7660

Space Fibers: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7375

Spot the Station: https://spotthestation.nasa.gov/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/Jorge Sotomayor, Lead Increment Scientist Expeditions 59/60/Orbiter.ch Aerospace/Roland Berga.

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