воскресенье, 31 марта 2019 г.

2019 March 31 Markarian’s Chain of Galaxies Image Credit…


2019 March 31


Markarian’s Chain of Galaxies
Image Credit & Copyright: Sergio Kaminsky


Explanation: Across the heart of the Virgo Cluster of Galaxies lies a striking string of galaxies known as Markarian’s Chain. The chain, pictured here, is highlighted on the right with two large but featureless lenticular galaxies, M84 and M86. Prominent to their lower left is a pair of interacting galaxies known as The Eyes. The home Virgo Cluster is the nearest cluster of galaxies, contains over 2000 galaxies, and has a noticeable gravitational pull on the galaxies of the Local Group of Galaxies surrounding our Milky Way Galaxy. The center of the Virgo Cluster is located about 70 million light years away toward the constellation of Virgo. At least seven galaxies in the chain appear to move coherently, although others appear to be superposed by chance.


∞ Source: apod.nasa.gov/apod/ap190331.html


Sneaking In Viruses are essentially lengths of DNA or RNA with…


Sneaking In


Viruses are essentially lengths of DNA or RNA with a protective protein coat hell-bent on exploiting your cells’ resources and abilities. They sneak inside and head to the nucleus – the cell’s control centre. The nucleus is shielded by an impenetrable fortress wall that only opens up when the cell divides – the nuclear envelope. HIV-1, however, manages to worm its way into the nucleus of cells that never divide. It heads for pores in the envelope – small, heavily guarded gates in the wall – but shouldn’t be able to get through because of its size. To understand how it slips in, researchers gave it a fluorescent label and watched it in action. HIV-1 (pink) binds first to a protein on the pore (Nup153, green), and then to another inside the nucleus, which pulls it through. Identifying this weakness in the fortress might lead researchers to new treatments to fortify defences, and keep HIV out.


Written by Anthony Lewis



You can also follow BPoD on Instagram, Twitter and Facebook


Archive link


Evidence of cannibalism found in Neolithic Spain

An interdisciplinary group of specialists in archaeology, anthropology and paleogenetics from Durham University (United Kingdom), the International Institute of Prehistoric Research of Cantabria (University of Santander) and the University of La Laguna has carried out research on the site of the Cueva de El Toro, in the Sierra del Torcal, near Antequera (Málaga), which has identified the oldest evidence of cannibalism in small-scale farming and pastoral communities on the Iberian Peninsula during the Early Neolithic (7,000 years ago).











Evidence of cannibalism found in Neolithic Spain
This skull cup, made from a human cranium, shows striations from stone tools; other marks indicate
that it was also boiled in a pottery vessel [Credit: J. Santana et al. 2019]

The advent of the Neolithic in the peninsula brought about profound changes in subsistence practices with food production, the first permanent settlements and the ideological and symbolistic transformation of rural communities. One of the most important enclaves to understand this process is the Cueva de El Toro, in the Sierra del Torcal, which, together with the sites at Menga, Viera and el Romeral, forms part of the properties included in the World Heritage Declaration of the Dolmens Site of Antequera. The excavation works, directed by Dimas Martín Socas and María Dolores Camalich Massieu, from the University of La Laguna, made it possible to document human occupations ranging from the Early Neolithic to the end of the Late Neolithic (5,000 years ago).
The discovery of the oldest archaeological evidence of cannibalism at this site involved various approaches and methods, the results of which were recently published in the American Journal of Physical Anthropology.


Study of the remains


The human remains present in the oldest levels of Cueva de El Toro belong to seven individuals: four adults, two teenagers of 15 and 12 years, and a child of 6 years of age. They appeared in two separate assemblages: the first consisted of a human skull cup that was carved to achieve a shape similar to that of a bowl and a jaw without evidence of manipulation, while the second contained several bone fragments from different anatomical parts dispersed in the habitat area with other remains of domestic activities such as debris from food consumption.











Evidence of cannibalism found in Neolithic Spain
Neolithic skull cup from Cueva de El Toro, Spain [Credit: J. Santana et al. 2019]

The first set of remains was intentionally arranged in a cache inside the cave next to four ceramic vessels that were probably placed as an offering. The crown skull, jaw and two bone remains of the domestic area were dated by Carbon 14 to determine their age, which ranges from 5,000 to 4,800 BC, suggesting that both sets are probably the result of the same time of human occupation of the cave.


DNA analysis of the skull cup and jaw confirms that these are different individuals. In fact, the skull cup did not have a direct kinship relationship with the other human remains analyzed in the cave.


Some of the bones of the second group present cut marks, intentional blows, tooth marks and signs of thermal alteration. The DNA analysis of some human remains has indicated a possible close relationship between two individuals, which could be maternal, mother and daughter, or sisters.


The analysis of these skeletal remains has allowed us to understand the process of preparing the skull cup, which would begin with the skinning of the scalp and, possibly, of the skin covering the face and the rest of the cranium. Subsequently, the facial skeleton and the base of the skull were fragmented and their edges carefully carved to achieve a regular morphology. It was then boiled in a ceramic vessel, generating some polishing marks, and removing any remaining tissue that might still be attached to the bone.


Evidence of cannibalism


As for the second group of human remains, coming from the domestic area, the type and intensity of manipulation observed suggest that some individuals were cooked over a fire. Similar manifestations have been documented in other Neolithic sites in the south of the Iberian Peninsula, such as Carigüela, Malalmuerzo and Majólicas, although without direct chronological information, which prevents the relationship with the remains of El Toro from being properly evaluated.











Evidence of cannibalism found in Neolithic Spain
Figure detailing the cut marks on the Neolithic skull cup from Cueva de El Toro, Spain
[Credit: J. Santana et al. 2019]

The interpretation of this evidence is complicated by its extraordinary character and two main hypotheses are proposed: aggressive cannibalism linked to episodes of extreme violence between different neolithic groups; or funerary cannibalism as part of a complex mortuary practice with multiple episodes.
It should be noted that two individuals in the second group show a first-degree relationship of kinship. This means that the inhabitants of El Toro consumed the bodies of the same family belonging to other groups, in the context of extreme violence against their enemies, or cannibalism took place in a family context where the dead of the relatives were consumed as part of a funeral ritual.


In both cases, it would probably be ritualized cannibalism with a strong symbolic connotation where the skull cup may have been involved. These hypotheses also affect the explanation of this singular piece with the inhabitants of El Toro: it could be a trophy head belonging to an enemy or, on the other hand, a relic of the inhabitants of the cave.


Source: Universidad de La Laguna [March 26, 2019]



TANN



Archive


Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert

Archaeologists in Egypt have uncovered ancient inscriptions on rock and stelae a well as ostraca at an amethyst mine at Wadi el-Hudi in Egypt’s Eastern Desert, east of Aswan. In antiquity it was a site of mines and settlements, where amethyst, gold, copper and granite were extracted.











Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
One of the stelae found at Wadi el-Hudi written in the name of Usersatet, the viceroy of Kush
[Credit: Wadi el-Hudi expedition/LiveScience]

More than 100 inscriptions carved into rock were discovered overall, along with 14 stelae and 45 ostraca. Some of the inscriptions are about 3,900 years old, while the ostraca date back about 2,000 years. Amethyst was very popular in Egypt at the time of the Middle Kingdom and was used in jewellery.
Although the site has undergone excavations in the past the Wadi el-Hudi expedition has discovered many inscriptions that had not been spotted earlier. The team conducting the research used several techniques such as 3D modelling, reflectance transformation imaging (RTI) and photogrammetry. Remains have been mapped and previously uncovered inscriptions have been re-analyzed.











Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
3D model of Site 5 at Wadi el-Hudi [Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
Site 4 at Wadi el-Hudi [Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
An ancient administrative building located at Wadi el-Hudi
[Credit: Wadi el-Hudi expedition/LiveScience]

Researchers believe that the inscriptions will offer an insight into the reality of Wadi el-Hudi at ancient times, since very little is known of the conditions the miners were working at the site and it is not clear whether they were workers or prisoners.
Some of the inscriptions indicate that the miners were proud of their work but others show groups of soldiers looking down at the mines; it is not clear whether these soldiers were protecting the site and the workers or guarding them. Also, it has not been clear to archaeologists how water was transferred to the miners. It is probable that water was carried from the Nile, 30 km away.











Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
In addition to over 100 written inscriptions, many petroglyphs were also found.
The soldier shown spearing a cow was drawn around 3,900 years ago, while
the cow was drawn several centuries earlier, researchers found
[Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
A scene showing two soldiers wrestling. One of the soldiers has grabbed the other by the neck.
An inscription on it reads: “Iqer who casts down the Asiatic “
[Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
Wadi el-Hudi expedition director Kate Liszka surveying the top of Site 5
[Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
Bryan Kraemer and Omer Farouk photographing a newly found stele
[Credit: Wadi el-Hudi expedition/LiveScience]










Inscriptions discovered at ancient amethyst mine in Egypt’s Eastern Desert
A member of the expedition team setting up a total station at dawn
[Credit: Wadi el-Hudi expedition/LiveScience]

Another discovery which has puzzled archaeologists is that of a 3,400-year-old stele bearing the name of a senior official, Usersatet (viceroy of Kush in the south) dating back to a time that no mining activity took place at Wadi el-Hudi and the site was no longer in use.


Researchers hope that further analyses and research of the new discoveries will shed more light to the above questions raised by archaeological evidence or lack of them.


The team’s work is rather urgent as works at gold mines in the area today are damaging archaeological evidence.


Source: Archaeology and Arts [March 28, 2019]



TANN



Archive


Willowford Turrets 48a and 48b, Hadrian’s Wall, Carlisle, 30.3.19.

Willowford Turrets 48a and 48b, Hadrian’s Wall, Carlisle, 30.3.19.









Source link


Find this and other great images in the Technology Networks new…


Find

this and other great images in the Technology Networks new The Spectacular

World of Cardiovascular Imaging Flipbook. Image of the Week – April 1, 2019


CIL:39057http://www.cellimagelibrary.org/images/39057


Description: This

is a colorized scanning electron micrograph showing a blood clot. Once

platelets arrive at the site of injury and form a plug, they activate clotting

factors. Fibrin is the most important clotting factor crosslinking with itself to

form a mesh (shown in this image as a string-like mesh). A blood clot is also

known as a thrombus and if this occurs when it is not required there can be

serious consequences, such as a stroke or a heart attack.


Authors: Kevin

MacKenzie


Licensing: Attribution-NonCommercial-NoDerivs 2.0 UK:

England & Wales (CC BY-NC-ND 2.0 UK) 


The Spectacular World of

Microbial Imaging Flipbook – https://www.technologynetworks.com/tn/ebooks/the-spectacular-world-of-microbial-imaging-flipbook-316089


Archive link


The International Space Station Through the Eyes of Little Earth!


Currently, six humans are living and working on the International Space Station, which orbits 250 miles above our planet at 17,500mph. Accompanying their mission is a zero-g indicator, informally known as “Little Earth”. 



Greetings fellow Earthlings! Curious about my first week on the International Space Station? What does a normal day look like when you’re living and working hundreds of miles above Earth? Take a look at some photos from my first week, when I was still learning the ropes from my new roommates!


Welcome Ceremony



Talk about a warm welcome! I arrived on March 3, 2019 when the SpaceX Crew Dragon docked to the Space Station for the first time. This historic mission marked the first time a commercially built American spacecraft intended for human spaceflight docked to the orbital lab. Though un-crewed, Dragon was carrying two very important passengers – my space travel companion Ripley and myself, Astronaut Little Earth. During my three-day introduction to the station, two Expedition 59 astronauts, Anne McClain and David Saint-Jacques, taught me what it takes to be a Space Station crew member!


Earth Watching


image

First thing’s first – the VIEW. After the traditional hatch opening welcome ceremony, I was off to the Cupola Observational Module. Designed for the observation of operations outside the station, this module’s six side windows also provide spectacular views of our Mother Earth! My roommate Anne McClain introduced me to the beautiful vantage point of space. Clearly, I was a little star-struck.


Space Suit Sizing


image

Next, it was time to get to work – lending a hand with Anne McClain’s space suit sizing. Did you know you actually grow in zero gravity? Astronaut McClain has grown two inches on her current mission in space. Crew members must account for this change in growth to know if different components need to be switched out of their individual spacesuit for a better fit. When pressurized and filled with oxygen, the spacesuits become stiff objects around the astronauts inside, making it critical they fit comfortably. These spacesuits are essentially mini spacecraft that provide protection and a means of survival for the astronauts as they venture outside the space station and into the harsh environment of space.


Space Coffee!


image


One Café Latte, please! I was thrilled to find out that even in space, the morning begins with a pick me up. Due to microgravity, liquids tend to get sticky and cling to the wall of cups, making these plastic pouches and straws necessary for consumption. Astronauts in 2015 got an upgrade to their morning cup of joe thanks to SpaceX, Lavazza and the Italian Space Agency. Named the ISSpresso, a microgravity coffee maker has brought authentic Italian espresso with zero-G coffee cups onto the International Space Station.


Emergency Mask Donning


image

Fueled up and ready for the day, my next agenda item was emergency preparedness practice. There is no 9-1-1 in space, and three events that could pose a dangerous threat to the Space Station include a fire, a depressurization event or an ammonia breakout. Here, Canadian Astronaut David Saint-Jacques and I practiced emergency mask donning in the unlikely event of an ammonia leak into the station’s atmosphere.


Preventative Maintenance


image

From astronaut to astro-plumber, I traded my mask for goggles with Astronaut Anne McClain during a briefing on plumbing routine maintenance. Because the International Space Station never returns to Earth, the crew is trained to regularly inspect, replace and clean parts inside the station.


Daily Exercise


image

Talk about staying healthy! After a busy day, Astronaut McClain and I continued to hit the ground running, literally. Crew members are required to work out daily for about two hours to help keep their heart, bones and muscles strong in zero gravity. The harness McClain is wearing is very much like a backpacking harness, designed to evenly distribute weight across her upper body and is attached to a system of bungees and cords. Depending on the tension in these attachments, a specific load of pressure is applied to her body onto the machine.


Strength Training in Zero-G


image

Watch out, deadlift going on. Running isn’t the only gym exercise they have onboard; strength training is also incorporated into the daily exercise regime.


Robotics Operations: Canadarm2 


image

You can look, just don’t touch they told me. Whoops. This was a definite highlight, my Canadarm 2 briefing. That black nob by my hand is the translational hand controller. It operates the up and down function of the 57.7-foot-long robotic arm. The Canadarm2 lends a literal helping hand with many station functions, using a “hand” known as a Latching End Effector to perform tasks such as in orbit maintenance, moving supplies and performing “cosmic catches”.


Crew Group Dinner 


image

Whew, you work up a big appetite working on the Space Station. Ending the day, I was introduced to a crew favorite, group dinner! Astronauts and cosmonauts from around the world come together on the orbital lab and bring with them a variety of cultures and … food! Though each country is responsible for feeding its own members, when on board the astronauts can share as they please. A new friend of mine, Paxi from the European Space Agency, welcomed my visit and we split a delicious space-shrimp cocktail.


And that’s a wrap to a busy first week aboard the International Space Station! Learn more about what it means to live and work aboard the International Space Station, and click here to see if you have what it takes to become a NASA Astronaut. Until next time!


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


Rivers raged on Mars late into its history

Long ago on Mars, water carved deep riverbeds into the planet’s surface–but we still don’t know what kind of weather fed them. Scientists aren’t sure, because their understanding of the Martian climate billions of years ago remains incomplete.











Rivers raged on Mars late into its history
A photo of a preserved river channel on Mars, taken by an orbiting satellite, with colour overlaid to show different
 elevations (blue is low, yellow is high) [Credit: NASA/JPL/Univ. Arizona/UChicago]

A new study by University of Chicago scientists catalogued these rivers to conclude that significant river runoff persisted on Mars later into its history than previously thought. According to the study, published in Science Advances, the runoff was intense–rivers on Mars were wider than those on Earth today–and occurred at hundreds of locations on the red planet.


This complicates the picture for scientists trying to model the ancient Martian climate, said lead study author Edwin Kite, assistant professor of geophysical sciences and an expert in both the history of Mars and climates of other worlds. “It’s already hard to explain rivers or lakes based on the information we have,” he said. “This makes a difficult problem even more difficult.”


But, he said, the constraints could be useful in winnowing the many theories researchers have proposed to explain the climate.


Mars is crisscrossed with the distinctive tracks of long-dead rivers. NASA’s spacecraft have taken photos of hundreds of these rivers from orbit, and when the Mars rover Curiosity landed in 2012, it sent back images of pebbles that were rounded–tumbled for a long time in the bottom of a river.


It’s a puzzle why ancient Mars had liquid water. Mars has an extremely thin atmosphere today, and early in the planet’s history, it was also only receiving a third of the sunlight of present-day Earth, which shouldn’t be enough heat to maintain liquid water “Indeed, even on ancient Mars, when it was wet enough for rivers some of the time, the rest of the data looks like Mars was extremely cold and dry most of the time,” Kite said.


Dotted lines mark where the preserved river channel is [Credit: NASA/JPL/Univ. Arizona/UChicago]


Seeking a better understanding of Martian precipitation, Kite and his colleagues analyzed photographs and elevation models for more than 200 ancient Martian riverbeds spanning over a billion years. These riverbeds are a rich source of clues about the water running through them and the climate that produced it. For example, the width and steepness of the riverbeds and the size of the gravel tell scientists about the force of the water flow, and the quantity of the gravel constrains the volume of water coming through.


Their analysis shows clear evidence for persistent, strong runoff that occurred well into the last stage of the wet climate, Kite said.


The results provide guidance for those trying to reconstruct the Martian climate, Kite said. For example, the size of the rivers implies the water was flowing continuously, not just at high noon, so climate modelers need to account for a strong greenhouse effect to keep the planet warm enough for average daytime temperatures above the freezing point of water.


The rivers also show strong flow up to the last geological minute before the wet climate dries up. “You would expect them to wane gradually over time, but that’s not what we see,” Kite said. The rivers get shorter–hundreds of kilometers rather than thousands–but discharge is still strong. “The wettest day of the year is still very wet.”


It’s possible the climate had a sort of “on/off” switch, Kite speculated, which tipped back and forth between dry and wet cycles.


“Our work answers some existing questions but raises a new one. Which is wrong: the climate models, the atmosphere evolution models, or our basic understanding of inner solar system chronology?” he said.


Source: University of Chicago [March 27, 2019]



TANN



Archive


Physicists constrain dark matter

Researchers from Russia, Finland, and the U.S. have put a constraint on the theoretical model of dark matter particles by analyzing data from astronomical observations of active galactic nuclei. The new findings provide an added incentive for research groups around the world trying to crack the mystery of dark matter: No one is quite sure what it is made of. The paper was published in the Journal of Cosmology and Astroparticle Physics.











Physicists constrain dark matter
This image of Centaurus A, one of the closest active galaxies to Earth, combines the data from observations in multiple frequency ranges [Credit: ESO/WFI (optical), MPIfR/ESO/APEX/A. Weiss et al. (submillimeter),
NASA/CXC/CfA/R. Kraft et al. (X-ray)]

The question of what particles make up dark matter is a crucial one for modern particle physics. Despite the expectations that dark matter particles would be discovered at the Large Hadron Collider, this did not happen. A number of then-mainstream hypotheses about the nature of dark matter had to be rejected. Diverse observations indicate that dark matter exists, but apparently something other than the particles in the Standard Model constitutes it. Physicists thus have to consider further options that are more complex. The Standard Model needs to be extended. Among the candidates for inclusion are hypothetical particles that may have masses in the range from 10?²? to 10??? times the mass of the electron. That is, the heaviest speculated particle has a mass 40 orders of magnitude greater than that of the lightest.
One theoretical model treats dark matter as being made up of ultralight particles. This offers an explanation for numerous astronomical observations. However, such particles would be so light that they would interact very weakly with other matter and light, making them exceedingly hard to study. It is almost impossible to spot a particle of this kind in a lab, so researchers turn to astronomical observations.


“We are talking about dark matter particles that are 28 orders of magnitude lighter than the electron. This notion is critically important for the model that we decided to test. The gravitational interaction is what betrays the presence of dark matter. If we explain all the observed dark matter mass in terms of ultralight particles, that would mean there is a tremendous number of them. But with particles as light as these, the question arises: How do we protect them from acquiring effective mass due to quantum corrections? Calculations show that one possible answer would be that these particles interact weakly with photons — that is, with electromagnetic radiation. This offers a much easier way to study them: by observing electromagnetic radiation in space,” said Sergey Troitsky, a co-author of the paper and chief researcher at the Institute for Nuclear Research of the Russian Academy of Sciences.


When the number of particles is very high, instead of individual particles, you can treat them as a field of certain density permeating the universe. This field coherently oscillates over domains that are on the order of 100 parsecs in size, or about 325 light years. What determines the oscillation period is the mass of the particles. If the model considered by the authors is correct, this period should be about one year. When polarized radiation passes through such a field, the plane of radiation polarization oscillates with the same period. If periodic changes like this do in fact occur, astronomical observations can reveal them. And the length of the period — one terrestrial year — is very convenient, because many astronomical objects are observed over several years, which is enough for the changes in polarization to manifest themselves.


The authors of the paper decided to use the data from Earth-based radio telescopes, because they return to the same astronomical objects many times during a cycle of observations. Such telescopes can observe remote active galactic nuclei — regions of superheated plasma close to the centers of galaxies. These regions emit highly polarized radiation. By observing them, one can track the change in polarization angle over several years.


“At first it seemed that the signals of individual astronomical objects were exhibiting sinusoidal oscillations. But the problem was that the sine period has to be determined by the dark matter particle mass, which means it must be the same for every object. There were 30 objects in our sample. And it may be that some of them oscillated due to their own internal physics, but anyway, the periods were never the same,” Troitsky goes on. “This means that the interaction of our ultralight particles with radiation may well be constrained. We are not saying such particles do not exist, but we have demonstrated that they don’t interact with photons, putting a constraint on the available models describing the composition of dark matter.”


“Just imagine how exciting that was! You spend years studying quasars, when one day theoretical physicists turn up, and the results of our high-precision and high angular resolution polarization measurements are suddenly useful for understanding the nature of dark matter,” enthusiastically adds Yuri Kovalev, a co-author of the study and laboratory director at the Moscow Institute of Physics and Technology and Lebedev Physical Institute of the Russian Academy of Sciences.


In the future, the team plans to search for manifestations of hypothesized heavier dark matter particles proposed by other theoretical models. This will require working in different spectral ranges and using other observation techniques. According to Troitsky, the constraints on alternative models are more stringent.


“Right now, the whole world is engaged in the search for dark matter particles. This is one of the great mysteries of particle physics. As of today, no model is accepted as favored, better-developed, or more plausible with regard to the available experimental data. We have to test them all. Inconveniently, dark matter is “dark” in the sense that it hardly interacts with anything, particularly with light. Apparently, in some scenarios it could have a slight effect on light waves passing through. But other scenarios predict no interactions at all between our world and dark matter, other than those mediated by gravity. This would make its particles very hard to find,” concludes Troitsky.


Source: Moscow Institute of Physics and Technology [March 27, 2019]



TANN



Archive


Data flows from NASA’s TESS Mission, leads to discovery of Saturn-sized planet

Astronomers who study stars are providing a valuable assist to the planet-hunting astronomers pursuing the primary objective of NASA’s new TESS Mission.











Data flows from NASA's TESS Mission, leads to discovery of Saturn-sized planet
A “hot Saturn” passes in front of its host star in this illustration. Astronomers who study stars used
“starquakes” to characterize the star, which provided critical information about the planet
[Credit: Gabriel Perez Diaz, Instituto de Astrofisica de Canarias]

In fact, asteroseismologists – stellar astronomers who study seismic waves (or “starquakes”) in stars that appear as changes in brightness – often provide critical information for finding the properties of newly discovered planets.


This teamwork enabled the discovery and characterization of the first planet identified by TESS for which the oscillations of its host star can be measured.


The planet – TOI 197.01 (TOI is short for “TESS Object of Interest”) – is described as a “hot Saturn” in a recently accepted scientific paper. That’s because the planet is about the same size as Saturn and is also very close to its star, completing an orbit in just 14 days, and therefore very hot.


The Astronomical Journal will publish the paper written by an international team of 141 astronomers. Daniel Huber, an assistant astronomer at the University of Hawaii at Manoa’s Institute for Astronomy, is the lead author of the paper. Steve Kawaler, a professor of physics and astronomy; and Miles Lucas, an undergraduate student, are co-authors from Iowa State University.


“This is the first bucketful of water from the firehose of data we’re getting from TESS,” Kawaler said.


TESS – the Transiting Exoplanet Survey Satellite, led by astrophysicists from the Massachusetts Institute of Technology – launched from Florida’s Cape Canaveral Air Force Station on April 18, 2018. The spacecraft’s primary mission is to find exoplanets, planets beyond our solar system. The spacecraft’s four cameras are taking nearly month-long looks at 26 vertical strips of the sky – first over the southern hemisphere and then over the northern. After two years, TESS will have scanned 85 percent of the sky.


Astronomers (and their computers) sort through the images, looking for transits, the tiny dips in a star’s light caused by an orbiting planet passing in front of it. NASA’s Kepler Mission – a predecessor to TESS – looked for planets in the same way, but scanned a narrow slice of the Milky Way galaxy and focused on distant stars.


TESS is targeting bright, nearby stars, allowing astronomers to follow up on its discoveries using other space and ground observations to further study and characterize stars and planets. In another paper recently published online by The Astrophysical Journal Supplement Series, astronomers from the TESS Asteroseismic Science Consortium (TASC) identified a target list of sun-like oscillating stars (many that are similar to our future sun) to be studied using TESS data – a list featuring 25,000 stars.


Kawaler – who witnessed the launch of Kepler in 2009, and was in Florida for the launch of TESS (but a last-minute delay meant he had to miss liftoff to return to Ames to teach) – is on the seven-member TASC Board. The group is led by Jorgen Christensen-Dalsgaard of Aarhus University in Denmark.


TASC astronomers use asteroseismic modeling to determine a host star’s radius, mass and age. That data can be combined with other observations and measurements to determine the properties of orbiting planets.


In the case of host star TOI-197, the asteroseismolgists used its oscillations to determine it’s about 5 billion years old and is a little heavier and larger than the sun. They also determined that planet TOI-197.01 is a gas planet with a radius about nine times the Earth’s, making it roughly the size of Saturn. It’s also 1/13th the density of Earth and about 60 times the mass of Earth.


Those findings say a lot about the TESS work ahead: “TOI-197 provides a first glimpse at the strong potential of TESS to characterize exoplanets using asteroseismology,” the astronomers wrote in their paper.


Kawaler is expecting that the flood of data coming from TESS will also contain some scientific surprises.


“The thing that’s exciting is that TESS is the only game in town for a while and the data are so good that we’re planning to try to do science we hadn’t thought about,” Kawaler said. “Maybe we can also look at the very faint stars – the white dwarfs – that are my first love and represent the future of our sun and solar system.”


Source: Iowa State University [March 27, 2019]




TANN



Archive


Study shows Arctic warming contributes to drought

According to new research led by a University of Wyoming scientist, similar changes could be in store today because a warming Arctic weakens the temperature difference between the tropics and the poles. This, in turn, results in less precipitation, weaker cyclones and weaker mid-latitude westerly wind flow — a recipe for prolonged drought.











Study shows Arctic warming contributes to drought
Credit: Flickr/torino071

The temperature difference between the tropics and the poles drives a lot of weather. When those opposite temperatures are wider, the result is more precipitation, stronger cyclones and more robust wind flow. However, due to the Arctic ice melting and warming up the poles, those disparate temperatures are becoming closer.


“Our analysis shows that, when the Arctic is warmer, the jet stream and other wind patterns tend to be weaker,” says co-author Bryan Shuman, a UW professor in the Department of Geology and Geophysics. “The temperature difference in the Arctic and the tropics is less steep. The change brings less precipitation to the mid-latitudes.”


Researchers from Northern Arizona University; Universite Catholique de Louvain in Louvain-In-Neuve, Belgium; the Florence Bascom Geoscience Center in Reston, Va.; and Cornell University also contributed to the paper.


“The Nature paper takes a global approach and relates the history of severe dry periods of temperature changes. Importantly, when temperatures have changed in similar ways to today (warming of the Arctic), the mid-latitudes — particularly places like Wyoming and other parts of central North America — dried out,” Shuman explains. “Climate models anticipate similar changes in the future.”


Currently, the northern high latitudes are warming at rates that are double the global average. This will decrease the equator-to-pole temperature gradient to values comparable with the early to middle Holocene Period, according to the paper.


Shuman says his research contribution, using geological evidence, was helping to estimate how dry conditions have been in the past 10,000 years. His research included three water bodies in Wyoming: Lake of the Woods, located above Dubois; Little Windy Hill Pond in the Snowy Range; and Rainbow Lake in the Beartooth Mountains.


“Lakes are these natural recorders of wet and dry conditions,” Shuman says. “When lakes rise or lower, it leaves geological evidence behind.”


The researchers’ Holocene temperature analysis included 236 records from 219 sites. During the past 10,000 years, many of the lakes studied were lower earlier in history than today, Shuman says.


“Wyoming had several thousand years where a number of lakes dried up, and sand dunes were active where they now have vegetation,” Shuman says. “Expanding to the East Coast, it is a wet landscape today. But 10,000 years ago, the East Coast was nearly as dry as the Great Plains.”


The research group looked at the evolution of the tropic-to-pole temperature difference from three time periods: 100 years ago, 2,000 years ago and 10,000 years ago. For the last 100 years, many atmospheric records facilitated the analysis but, for the past 2,000 years or 10,000 years, there were fewer records available. Tree rings can help to expand studies to measure temperatures over the past 2,000 years, but lake deposits, cave deposits and glacier ice were studied to record prior temperatures and precipitation.


“This information creates a test for climate models,” Shuman says. “If you want to use a computer to make a forecast of the future, then it’s useful to test that computer’s ability to make a forecast for some other time period. The geological evidence provides an excellent test.”


Source: University of Wyoming [March 27, 2019]



TANN



Archive


The sword of a Hispano-Muslim warlord is digitized in 3D

At age 90, Ali Atar, one of the main military chiefs of King Boabdil of Granada, fought to his death in the Battle of Lucena in 1483. It was there that his magnificent Nasrid sword was taken away from him, and researchers from the Polytechnic University of Valencia and a company from Toledo have now modelled it in order to graphically document and present it on the web.











The sword of a Hispano-Muslim warlord is digitized in 3D
3D modelling process of Ali Atar’s Nasrid sword [Credit: Ingheritag3D]

Ali Atar, Warden of Loja and Lord of Zagra, was a Hispano-Muslim warlord at the service of King Boabdil, the last sultan of Granada, to whom he was also related when he married his daughter Moraima. In April 1483 Boabdil tried to take the Christian city of Lucena (Cordoba) with the help of his father-in-law, but they lost the battle: the Nasrid king was captured and Ali Atar died fighting at the age of 90.
His magnificent sword, covered with gold, ivory and precious metals then passed into the hands of the Christians and, after many historical vicissitudes, this Andalusian treasure is now preserved and exhibited in the Toledo Army Museum (MUSEJE, Spanish acronym, Museo del Ejercito).











The sword of a Hispano-Muslim warlord is digitized in 3D
The sword has been digitalized in the workshops of the Toledo Army Museum (MUSEJE) 
[Credit: Ingheritag3D]

To graphically document this valuable piece and make it known through the web, researchers from the Universitat Politecnica de Valencia (UPV, Spain) and the company Ingheritag3D have carried out a three-dimensional digitization process.
First they photographed the sword from many angles using a technique called photogrammetry. Then they overlapped all the images, drew planimetries (drawings of the meticulous filigree of the grip) and generated its 3D model.











The sword of a Hispano-Muslim warlord is digitized in 3D
Photogrammetric image [Credit: Ingheritag3D]

“These techniques offer the possibility of valuing relevant pieces inside and outside museums, since three-dimensional modelling is prepared both for specialists -who can manipulate the piece virtually-, and for being shared publicly and interactively through the Internet,” says engineer Margot Gil-Meliton, co-author of the work.
Using a web viewer, any user can use their mouse to check an exact replica of the handle of this genet sword, a type of genuinely Nasrid weapon introduced in Al-Andalus by the Zenetas (Berber people from whom it takes its name). Ali Atar’s sword has a knob in the shape of a bulbous dome, an ivory fist carved with drawings and Arabic letters, and a golden arriax (sword grip) topped with zoomorphic figures.



To record the details of this fine ornamentation, the researchers have devised solutions that have facilitated the analysis of highly reflective materials and complicated geometries. Their workflow could also be applied to characterize other museum pieces.


The other author of the study, Professor Jose Luis Lerma of the UPV, concludes: “A resource as valuable as cultural heritage can no longer be satisfied with physical conservation: it must be complemented by exhaustive digital preservation in all its forms, which facilitates the investigation of the pieces, their correct safeguarding and dissemination of knowledge to the general public.”


The study has just been published in Virtual Archaeology Review.


Source: Spanish Foundation for Science and Technology (FECYT) [March 27, 2019]



TANN



Archive


2000-year-old agricultural village discovered in excavations in Jerusalem

Impressive remains of a Jewish village from the Hasmonean period, approximately 2000 years ago, are currently being uncovered in a salvage excavation conducted by the Israel Antiquities Authority​ in the Sharafat neighborhood of Jerusalem, where an elementary school will be built. The excavation, funded by the Moriah Jerusalem development corporation, on behalf of the Jerusalem municipality, has yielded remains of a large wine press containing fragments of many storage jars, a large columbarium cave (rock-cut dovecote), an olive press, a large ritual bath (mikveh, in addition to another mikveh previously discovered at this site), a water cistern, rock quarries and installations.











2000-year-old agricultural village discovered in excavations in Jerusalem
The ancient olive press uncovered at the site [Credit: Ya`akov Billig, Israel Antiquities Authority]

The most significant feature of the excavation is an extravagant burial estate, which included a corridor leading to a large courtyard chiseled into the bedrock. The courtyard had an encompassing bench, with the entrance to the burial cave from its façade. The cave included several chambers, each with oblong burial niches (Kochim) chiseled into the walls. In order to respect the buried parties, and in accordance with the orthodox restrictions of disturbing the burials, the cave was sealed.
Ya’akov Billig, Director of the excavations on behalf of the Israel Antiquities Authority, stated: “It seems that this burial estate served a wealthy or prominent family during the Hasmonean period. The estate was in use for a few generations as was common in that era”.











2000-year-old agricultural village discovered in excavations in Jerusalem
Excavations at the Hasmonean village in Sharafat [Credit: Israel Antiquities Authority]

The earth which covered the courtyard of the burial estate contained some large building stones, some of which are elaborate architectural elements common during the Second Temple period. Most interesting is a Doric capital of a heart-shaped pillar. A few cornice fragments were also found. Such quality craftsmanship of architectural elements is very rare, found mostly in monumental buildings or burial estates in the Jerusalem area, such as the burial estate of the priestly family of Benei Hazir in the Kidron valley and several tombs in the Sanhedriah neighborhood.
The current excavation has only exposed just a small part of a larger village that existed to its south. However, despite the small exposure, the finds seem to indicate that the village was of agricultural nature, and among other things produced wine and olive oil, as well as breeding doves. Doves were an important commodity during the time of the Second Temple and in other periods as well, as meat and eggs were consumed by the people and also used for sacrificial offerings at the temple. The doves’ droppings were used as fertilizer for agriculture. Columbarium caves, designated installations used for breeding the doves, are a known feature in the Jerusalem area.


Source: Israel Ministry of Foreign Affairs [March 27, 2019]



TANN



Archive


UNESCO weighs in on controversy over Hagia Sophia

In response to the intention announced this week by Turkish President Recep Tayyip Erdogan to turn the Hagia Sophia monument – originally a Byzantine Christian cathedral and now a museum – into a mosque after his country’s local elections on Sunday, UNESCO sources cited by the Greek media clarified on Wednesday that changing the World Heritage site’s status would require approval by the Paris-based organization.











UNESCO weighs in on controversy over Hagia Sophia
Credit: Reuters/Umit Bektas

The 6th century Hagia Sophia was the main seat of the Greek Orthodox Church and was turned into a mosque following the Ottoman conquest of Istanbul – then Constantinople – in 1453. It became a museum in 1935.


Erdogan revisited the issue on Wednesday, saying his suggestion to convert the monument into a mosque is a response to US President Donald Trump’s decision to recognize the Golan Heights which Israel gained in 1967 from Syria as Israeli territory. He also vowed that “Constantinople will never exist again.” “The name of this area is Islambol (full of Islam) and you know that,” he said.


For its part, Athens has attributed the spike in incendiary rhetoric and the surge in violations of Greek airspace to the political uncertainty in Turkey stemming from this Sunday’s elections.


Turkey’s belligerent stance was on full display on Monday, with multiple airspace violations just a hours after the Greek Foreign Ministry lodged a demarche to protest against the harassment of the helicopter Prime Minister Alexis Tsipras was traveling in.


There was no letup up on Wednesday as Turkish jets conducted multiple airspace violations in a region spanning the northern Aegean and the Eastern Mediterranean.


New Democracy shadow foreign minister Giorgos Koumoutsakos said the violations made it “clear that Ankara does not wish for a de-escalation of tension but continuously wants more Greek concessions.”


Source: Kathimerini [March 27, 2019]



TANN



Archive


3,000 year-old silver cup unearthed in northwestern Iran

Archaeologists have unearthed a 3,000-year-old silver goblet during excavation work carried out in the Ardabil province of northwestern Iran, media reports said Wednesday.











3,000 year-old silver cup unearthed in northwestern Iran
Credit: IRNA

Nader Fallahi, head of the Directorate General of Heritage, Handicrafts, and Tourism of Ardebil told Iranian state agency IRNA that the silver goblet was found during excavations carried out in the Khalkhal district.


Fallahi said that the ancient artefact may have belonged to the Mannaean kingdom that ruled the region between 850 and 616 BC.


He noted that excavations and research by the experts showed that there was life in the area 300 years before the Achaemenid Empire, also known as the First Persian Empire which began in 550 BC.


“The goblet can be compared with the silver goblets discovered at the Hasanlu region in (the Iranian province of) West Azerbaijan,” he added, referring to the ancient archaeological site located in Iran’s Solduz Valley.


The silver goblet will be showcased in the Archaeological Museum of Khalkhal.


Source: Daily Sabah [March 27, 2019]



TANN



Archive


Featured

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

Popular