четверг, 16 мая 2019 г.

Hubble Observes Creative Destruction as Galaxies Collide



On the verge




Distant view of a galactic crash — NGC 4490 and NGC 4485 (ground-based image)




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Zoom-in on NGC 4485



Zoom-in on NGC 4485


Pan on NGC 4485



Pan on NGC 4485






The NASA/ESA Hubble Space Telescope has taken a new look at the spectacular irregular galaxy NGC 4485, which has been warped and wound by its larger galactic neighbour. The gravity of the second galaxy has disrupted the ordered collection of stars, gas and dust, giving rise to an erratic region of newborn, hot, blue stars and chaotic clumps and streams of dust and gas.


The irregular galaxy NGC 4485 has been involved in a dramatic gravitational interplay with its larger galactic neighbour NGC 4490 — out of frame to the bottom right in this image. Found about 30 million light-years away in the constellation of Canes Venatici (the Hunting Dogs), the strange result of these interacting galaxies has resulted in an entry in the Atlas of Peculiar galaxies: Arp 269.


Having already made their closest approach, NGC 4485 and NGC 4490 are now moving away from each other, vastly altered from their original states. Still engaged in a destructive yet creative dance, the gravitational force between them continues to warp each of them out of all recognition, while at the same time creating the conditions for huge regions of intense star formation.


This galactic tug-of-war has created a stream of material about 25 000 light-years long which connects the two galaxies. The stream is made up of bright knots and huge pockets of gassy regions, as well as enormous regions of star formation in which young, massive, blue stars are born. Short-lived, however, these stars quickly run out of fuel and end their lives in dramatic explosions. While such an event seems to be purely destructive, it also enriches the cosmic environment with heavier elements and delivers new material to form a new generation of stars.


Two very different regions are now apparent in NGC 4485; on the left are hints of the galaxy’s previous spiral structure, which was at one time undergoing “normal” galactic evolution. The right of the image reveals a portion of the galaxy ripped towards its larger neighbour, bursting with hot, blue stars and streams of dust and gas.


This image, captured by the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope, adds light through two new filters compared with an image released in 2014. The new data provide further insights into the complex and mysterious field of galaxy evolution.



More Information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
Image credit: ESA, NASA



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Contacts


Bethany Downer
ESA/Hubble, Public Information Officer
Garching, Germany
Email: bethany.downer@partner.eso.org






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3,500-year-old cave burials found in Western Pyrenees

The oldest documented human remains in the Western Pyrenees have been discovered at Pallars Sobirà in the Siarb Valley (Catalonia).











3,500-year-old cave burials found in Western Pyrenees
Preliminary exploration and excavation of the Cova de l’Home Mort in 2017
[Credit: ACN]

The remains were found in the Cova de l’Home Mort, a small cave located at an altitude of 1,170 metres. It is situated in a difficult-to-access location, facing north-east and is formed by two narrow galleries measuring just over 50 square metres between them.











3,500-year-old cave burials found in Western Pyrenees
Archaeologist Ermengol Gassiot inside the Cova de l’Home Mort
[Credit: ACN]

A thorough investigation of only the first 80 centimetres of the deposits has enabled the recovery of the remains of at least seven people, including newborn babies, children between the ages of 6 and 7, and adults, as well as numerous animal bones, ceramics and stone tools.











3,500-year-old cave burials found in Western Pyrenees
Remains of a ceramic vase found inside the cave
[Credit: ACN]

The professor of archaeology at the Autonomous University of Barcelona, Ermengol Gassiot, highlighted «the exceptional» state of preservation of the site, and affirmed that «it will allow for an in-depth study of how the populations of 3,500 years ago were in the High Pyrenees», and also believed that «the further progress of his research will yield more information of still older human occupation.»











3,500-year-old cave burials found in Western Pyrenees
Human remains and stone tool located inside the Cova de l’Home Mort
[Credit: ACN]

Gassiot says that the remains of two different individuals have been dated to the Middle Bonze Age, ie. around 1,500 BC and that the Cova de l’Home Mort was used as a sepulchral cave for at least 120 years.



Although the pottery found in the cave appears to date from the time of the burials, Gassiot is hopeful that subsequent campaigns will lead to lower Neolithic levels.


Source: Corporació Catalana de Mitjans Audiovisuals [May 14, 2019]



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Academic cracks Voynich code, solving century-old mystery of medieval text

A University of Bristol academic has succeeded where countless cryptographers, linguistics scholars and computer programs have failed — by cracking the code of the ‘world’s most mysterious text’, the Voynich manuscript.











Academic cracks Voynich code, solving century-old mystery of medieval text
Vignette A illustrates the erupting volcano that prompted the rescue mission and the drawing of the map. It rose from
the seabed to create a new island given the name Vulcanello, which later became joined to the island of Vulcano following
another eruption in 1550. Vignette B depicts the volcano of Ischia, vignette C shows the islet of Castello Aragonese,
and vignette D represents the island of Lipari. Each vignette includes a combination of naïvely drawn and somewhat
 stylized images along with annotations to explain and add detail. The other five vignettes describe further
 details of the story [Credit: Voynich manuscript]

Although the purpose and meaning of the manuscript had eluded scholars for over a century, it took Research Associate Dr. Gerard Cheshire two weeks, using a combination of lateral thinking and ingenuity, to identify the language and writing system of the famously inscrutable document.
In his peer-reviewed paper published in the journal Romance Studies, Cheshire describes how he successfully deciphered the manuscript’s codex and, at the same time, revealed the only known example of proto-Romance language.


«I experienced a series of ‘eureka’ moments whilst deciphering the code, followed by a sense of disbelief and excitement when I realised the magnitude of the achievement, both in terms of its linguistic importance and the revelations about the origin and content of the manuscript.











Academic cracks Voynich code, solving century-old mystery of medieval text
This shows the word ‘palina’ which is a rod for measuring the depth of water, sometimes called
a stadia rod or ruler. The letter ‘p’ has been extended [Credit: Voynich manuscript]

«What it reveals is even more amazing than the myths and fantasies it has generated. For example, the manuscript was compiled by Dominican nuns as a source of reference for Maria of Castile, Queen of Aragon, who happens to have been great aunt to Catherine of Aragon.
«It is also no exaggeration to say this work represents one of the most important developments to date in Romance linguistics. The manuscript is written in proto-Romance — ancestral to today’s Romance languages including Portuguese, Spanish, French, Italian, Romanian, Catalan and Galician. The language used was ubiquitous in the Mediterranean during the Medieval period, but it was seldom written in official or important documents because Latin was the language of royalty, church and government. As a result, proto-Romance was lost from the record, until now.»


Cheshire explains in linguistic terms what makes the manuscript so unusual: «It uses an extinct language. Its alphabet is a combination of unfamiliar and more familiar symbols. It includes no dedicated punctuation marks, although some letters have symbol variants to indicate punctuation or phonetic accents. All of the letters are in lower case and there are no double consonants. It includes diphthong, triphthongs, quadriphthongs and even quintiphthongs for the abbreviation of phonetic components. It also includes some words and abbreviations in Latin.»













Academic cracks Voynich code, solving century-old mystery of medieval text

This shows two women dealing with five children in a bath. The words describe different temperaments: tozosr (buzzing:
too noisy), orla la (on the edge: losing patience), tolora (silly/foolish), noror (cloudy: dull/sad), or aus (golden bird:
well behaved), oleios (oiled: slippery). These words survive in Catalan [tozos], Portuguese [orla], Portuguese [tolos],
 Romanian [noros], Catalan [or aus] and Portuguese [oleio]. The words orla la describe the mood
of the woman on the left and may well be the root of the French phrase ‘oh là là’, which has a
very similar sentiment [Credit: Voynich manuscript]

The next step is to use this knowledge to translate the entire manuscript and compile a lexicon, which Cheshire acknowledges will take some time and funding, as it comprises more than 200 pages.


«Now the language and writing system have been explained, the pages of the manuscript have been laid open for scholars to explore and reveal, for the first time, its true linguistic and informative content.»


Source: University of Bristol [May 15, 2019]



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Chewing gums reveal the oldest Scandinavian human DNA

The first humans who settled in Scandinavia more than 10,000 years ago left their DNA behind in ancient chewing gums, which are masticated lumps made from birch bark pitch. This is shown in a new study conducted at Stockholm University and published in Communications Biology.











Chewing gums reveal the oldest Scandinavian human DNA
Masticate being examined [Credit: Natalija Kashuba/
Stockholm University]

There are few human bones of this age, close to 10 000 years old, in Scandinavia, and not all of them have preserved enough DNA for archaeogenetic studies. In fact, the DNA from these newly examined chewing gums is the oldest human DNA sequenced from this area so far. The DNA derived from three individuals, two females and one male, creates an exciting link between material culture and human genetics.


Ancient chewing gums are as of now an alternative source for human DNA and possibly a good proxy for human bones in archaeogenetic studies. The investigated pieces come from Huseby-Klev, an early Mesolithic hunter-fisher site on the Swedish west coast. The sites excavation was done in the early 1990’s, but at this time it was not possible to analyse ancient human DNA at all, let alone from non-human tissue. The masticates were made out of birch bark tar and used as glue in tool production and other types of technology during the Stone Age.


«When Per Persson and Mikael Maininen proposed to look for hunter-gatherer DNA in these chewing gums from Huseby Klev we were hesitant but really impressed that archaeologists took care during the excavations and preserved such fragile material», says Natalija Kashuba, who was affiliated to The Museum of Cultural History in Oslo when she performed the experiments in cooperation with Stockholm University.


«It took some work before the results overwhelmed us, as we understood that we stumbled into this almost ‘forensic research’, sequencing DNA from these mastic lumps, which were spat out at the site some 10 000 years ago!» says Natalija Kashuba. Today Natalija is a Ph.D. student at Uppsala University.











Chewing gums reveal the oldest Scandinavian human DNA
Excavation of the site in the 1990’s [Credit: Per Persson/
Stockholm University]

The results show that, genetically, the individuals whose DNA was found share close genetic affinity to other hunter-gatherers in Sweden and to early Mesolithic populations from Ice Age Europe. However, the tools produced at the site were a part of lithic technology brought to Scandinavia from the East European Plain, modern day Russia. This scenario of a culture and genetic influx into Scandinavia from two routes was proposed in earlier studies, and these ancient chewing gums provides an exciting link directly between the tools and materials used and human genetics.
Emrah Kirdök at Stockholm University conducted the computational analyses of the DNA. «Demography analysis suggests that the genetic composition of Huseby Klev individuals show more similarity to western hunter-gatherer populations than eastern hunter-gatherers», he says.


«DNA from these ancient chewing gums have an enormous potential not only for tracing the origin and movement of peoples long time ago, but also for providing insights in their social relations, diseases and food.», says Per Persson at the Museum of Cultural History in Oslo. «Much of our history is visible in the DNA we carry with us, so we try to look for DNA where ever we believe we can find it», says Anders Götherström, at the Archaeological Research Laboratory at Stockholm University, where the work was conducted. The study is published in Communications Biology.


Source: Stockholm University [May 15, 2019]



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Neanderthals and modern humans diverged at least 800,000 years ago

Neanderthals and modern humans diverged at least 800,000 years ago, substantially earlier than indicated by most DNA-based estimates, according to new research by a UCL academic.











Neanderthals and modern humans diverged at least 800,000 years ago
Dental morphology [Credit: Aida Gómez-Robles]

The research, published in Science Advances, analysed dental evolutionary rates across different hominin species, focusing on early Neanderthals. It shows that the teeth of hominins from Sima de los Huesos, Spain — ancestors of the Neanderthals — diverged from the modern human lineage earlier than previously assumed.


Sima de los Huesos is a cave site in Atapuerca Mountains, Spain, where archaeologists have recovered fossils of almost 30 people. Previous studies date the site to around 430,000 years ago (Middle Pleistocene), making it one of the oldest and largest collections of human remains discovered to date.


Dr Aida Gomez-Robles (UCL Anthropology), said: «Any divergence time between Neanderthals and modern humans younger than 800,000 years ago would have entailed an unexpectedly fast dental evolution in the early Neanderthals from Sima de los Huesos.»


«There are different factors that could potentially explain these results, including strong selection to change the teeth of these hominins or their isolation from other Neanderthals found in mainland Europe. However, the simplest explanation is that the divergence between Neanderthals and modern humans was older than 800,000 years. This would make the evolutionary rates of the early Neanderthals from Sima de los Huesos roughly comparable to those found in other species.»


Modern humans share a common ancestor with Neanderthals, the extinct species that were our closest prehistoric relatives. However, the details on when and how they diverged are a matter of intense debate within the anthropological community.











Neanderthals and modern humans diverged at least 800,000 years ago
Hominin teeth [Credit: Aida Gómez-Robles]

Ancient DNA analyses have generally indicated that both lineages diverged around 300,000 to 500,000 years ago, which has strongly influenced the interpretation of the hominin fossil record.


This divergence time, however, is not compatible with the anatomical and genetic Neanderthal similarities observed in the hominins from Sima de los Huesos. The Sima fossils are considered likely Neanderthal ancestors based on both anatomical features and DNA analysis.


Dr Gomez-Robles said: «Sima de los Huesos hominins are characterised by very small posterior teeth (premolars and molars) that show multiple similarities with classic Neanderthals. It is likely that the small and Neanderthal-looking teeth of these hominins evolved from the larger and more primitive teeth present in the last common ancestor of Neanderthals and modern humans.»


Dental shape has evolved at very similar rates across all hominin species, including those with very expanded and very reduced teeth. This new study examined the time at which Neanderthals and modern humans should have diverged to make the evolutionary rate of the early Neanderthals from Sima de los Huesos similar to those observed in other hominins.


The research used quantitative data to measure the evolution of dental shape across hominin species assuming different divergent times between Neanderthals and modern humans, and accounting for the uncertainty about the evolutionary relationships between different hominin species.


«The Sima people’s teeth are very different from those that we would expect to find in their last common ancestral species with modern humans, suggesting that they evolved separately over a long period of time to develop such stark differences.»


The study has significant implications for the identification of Homo sapiens last common ancestral species with Neanderthals, as it allows ruling out all the groups postdating 800,000 year ago.


Source: University College London [May 15, 2019]



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Ancient fish ponds in the Bolivian savanna supported human settlement

A network of fish ponds supported a permanent human settlement in the seasonal drylands of Bolivia more than one thousand years ago, according to a new study published in the open-access journal PLOS ONE by Gabriela Prestes-Carneiro of Federal University of Western Para, Brazil, and colleagues. The study is the first to document the full range of fish species likely kept in these constructed ponds, and provides new insights into how humans modified the savannah environment to cope with the months-long droughts that characterize this region of the Amazon Basin.











Ancient fish ponds in the Bolivian savanna supported human settlement
Interior of circular pond with canal exit visible in the center of the far margin
[Credit: Prestes-Carneiro et al. 2019]

The Llanos de Mojos region in central Bolivia is a vast plain which receives flooding rains from October to April, and then virtually no precipitation the rest of the year. Beginning about 500 AD, humans began to create monumental earthen mounds in the region, on which permanent settlements were established. One, called Loma Salavtierra, located more than 50 kilometers from the nearest major river, has become an important archaeological site.
Previous work has established the existence of a series of shallow ponds rimmed by low earthen walls and connected by canals, which are believed to have captured rainfall and stored it throughout the dry season, potentially built to serve multiple purposes including water storage, drainage, and fish management.











Ancient fish ponds in the Bolivian savanna supported human settlement
Fish remains from Loma Salvatierra [Credit: Prestes-Carneiro et al, 2019]

In the current study, the authors conducted osteological and taxonomic identifications on the remains of over 17,000 fish found in midden piles at the site with the aid of a comparative collection. They identified more than 35 different taxa of fish, with four types of fish predominating: swamp-eels, armored catfish, lungfish, and tiger-fish, all of which are adapted to conditions of low oxygen and fluctuating water levels, as would be expected to arise in the ponds during the long dry period between annual rains.
Together with evidence of similar pond networks elsewhere in the region, the authors suggest that their results point to the use of these ponds for harvesting fish year-round, far from any rivers, permanent natural ponds, or other open-water habitat. Further studies will be needed to investigate fish storage and holding activities, and whether these activities changed in response to precipitation and landscape fluctuations.


The authors add: «The savanna, in contrast to the large Amazonian rivers, presents a distinct set of fishing habitats where humans likely established specific fishing strategies.»


Source: Public Library of Science [May 15, 2019]



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Quantum physicists shining new light on cave art

Leslie Van Gelder, a well-known American-born archaeologist has been working with Dr. Harald Schwefel, and other physicists at Otago University to develop a lamp that mimics the flickering torch light that paleolithic cave artists worked by many thousands of years ago. The lamps will help Leslie and other archaeologists reveal intimate details of these ancient people.











Quantum physicists shining new light on cave art
Tallow candle burning in stone lamp [Credit: Leslie Van Gelder]

The collaboration brings together quantum physicists and archaeologists with indigenous Australian land-owners, deer stalkers, artists, ancient DNA specialists, university students and a product designer. The story shows the unexpected ways cutting edge science research can enrich cultural understanding and heritage. It speaks to a willingness and generosity in the New Zealand science community to try something different and help each other out.


Tens of thousands of years ago ancient people of Europe and Australia trekked deep into caves by torchlight creating images on the walls of horses, bison, reindeer and stencil outlines of their own hands. In the flickering firelight of their ancient lamps, the figures would appear to move. The shadows on the curved cave walls gave them an illusion of volume and life and the colours appeared inky-rich and deep. This was how the ancient artists would have seen their work. But in the past few decades open flames have been banned in heritage cave sights and the LED lights that replaced them have taken away much of the mystery.


«The flat grey and white light of the torches made with LED’s produce an almost clinical light and rob the animals of their warm colors and their shadows,» Leslie says.


It was a conversation with a cave guide in Europe in 2016 that gave Leslie the idea for creating the new lamps. Not only could this give a more authentic experience of the caves. It would also help to answer important research questions.


As a researcher I have been drawn to questions of light for the last decade,» Leslie says. «These new lamps will help us to explore questions of how people moved through the caves and drew the on the walls… Some of the images are found high up in hard to reach places. The artists would have had to climb five metres up a wall or stalactite to reach them, which would require both hands. So someone else must have held the light. I have a soft spot for the people in the shadows who might not have made the drawings themselves but allowed someone else to by holding their light.»


Leslie returned to Glenorchy in New Zealand where she lives, with a mission to find a more authentic lighting solution. The first step was to try to create an authentic copy of the ancient lamps to work out what qualities of the light the lamps needed to mimic. She sourced animal fat from local deerstalkers and a butcher to mimic the reindeer and auroch tallow used in ancient lamps. She worked with a local sculptor to fashion a stone base using primitive tools.


To create a modern equivalent she needed some physicists. This is where the Dodd-Walls Centre comes in. This national centre of collaborative research brings together scientists across the country doing world-leading research in light and quantum science. Leslie discovered the Director of the Dodd-Walls Centre, Professor David Hutchinson while searching the University of Otago website.











Quantum physicists shining new light on cave art
Lamp and flutings [Credit: Leslie Van Gelder]

«He looked approachable and was leading an interdisciplinary centre that focuses on light,» says Leslie. «So I wrote to him. He replied straight away and said he could help. I wasn’t expecting it to be that easy!»


Professor Hutchinson put Leslie in touch with Dr. Schwefel, a Principal Investigator with the Dodd-Walls Centre, also based at the University of Otago. In his core research Dr. Schwefel develops world-leading components for incredibly powerful quantum computers. He recently published a paper in the prestigious scientific journal Nature announcing his invention of a device that could revolutionise internet efficiency and speed. So this project came out of left field.


«It was really great to see how we could use our knowledge of light and its spectral properties to provide help for the archaeology community» says Dr. Schwefel. «Once we identified what we wanted to achieve in terms of the flickering pattern and spectrum, then it was pretty straight-forward to devise a candle-like structure that had the correct flickering pattern.»


Dr. Schwefel brought in two Ph.D. students as consultants and a summer student Timothy Marshall, who worked with the Dodd-Walls Centre Industry manager, Luke Taylor to create the product. The Dodd-Walls Centre funded the whole project.


«They asked me for a Christmas wish list of all the things I wanted the lamp to do,» Leslie explains. «It’s incredibly hard to find funding in the archaeology community,» Leslie says. «This was an amazing gift to have their support.»


In the summer of 2018-19, Timothy worked with Dr. Schwefel and Luke Taylor to produce six hand held lamps that Leslie could take as prototypes to a cave in Australia where she was working in March.


«Working to my ‘wish list’ for color, intensity, and flicker, their team did an amazing job and a week before I left, a suitcase arrived for me in Glenorchy that had 6 beautiful lamps. The glass for them had been hand blown by the chemistry department’s glassblower, the bodies of each lamp mimicked stone from different parts of the world and the mechanism were three LED lights colored to the sodium line they had discovered in their light spectrum analysis. Luke and Timothy had done a series of experiments with wind and wick length to produce a series of potential flicker patterns so the lamps in the end had 13 different intensity and flicker pattern that I could change with just the flick of a button. Magic!»


There was an almost audible silence when the team of scientists, archaeologists and traditional indigenous land owners entered the cave in Australia that Leslie had lit using the new lamps.


«It was a very moving experience to see the cave in the flickering warm light of the ‘paleo-lamps,» Leslie says.


This is just the beginning of the collaboration. Having discovered ancient fire-sticks in the Australian cave, Leslie will work with Harald and the team alongside the local Aboriginal community to develop a new lamp to mimic its light.


Even though the project was tangent to Harald’s core focus on quantum computing and photonics, it provided an excellent opportunity to contribute to a new field. It also gave the students valuable experience of developing a product and getting it to market with a deadline.


According to Leslie the archaeology community have been impressed and inspired by the project. presented the story at a specialist conference on rock art.


«I presented the story at a rock art conference recently,» She says. «Some archaeologists told me it restored their faith in archaeology. There is a real respect and interest in the perspective from another field like physics.»


Next spring Leslie will be returning to Europe to continue her cave research there. She will be taking with her a box of the new lamps as a gift from the Dodd-Walls Centre.


«I look forward to seeing what we might be able to see for the first time in the shadows and flickering lights of our lamps,» Leslie says.


Author: Leslie Van Gelder | Source: University of Otago [May 16, 2019]



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Video: Fly over Mount Sharp on Mars


NASA — Mars Science Laboratory (MSL) patch.


May 16, 2019



Animation above: This animation shows a proposed route for NASA’s Curiosity rover, which is climbing lower Mount Sharp on Mars. The annotated version of the map labels different regions that scientists working with the rover would like to explore in coming years. Animation Credit: NASA/JPL-Caltech/ESA/University of Arizona/JHUAPL/MSSS/USGS Astrogeology Science Center.


Ever wanted to visit Mars? A new animated video shows what it would be like to soar over Mount Sharp, which NASA’s Curiosity rover has been climbing since 2014.


This video highlights several regions on the mountain that are intriguing to Curiosity’s scientists, chief among them what the science team calls the «clay-bearing unit,» where Curiosity has just started analyzing rock samples. The aerial tour also shows the roving science lab’s proposed path in the years to come. Intriguing targets include the rocky cliffs of the «sulfate-bearing unit,» where sulfate minerals may indicate the area was drying up or becoming more acidic in ancient times, and Gediz Vallis, where a river may have carved a path through the sulfate unit.



NASA’s Curiosity Finds Climate Clues on a Martian Mountain

Video above: After spending the better part of a year exploring Mars’ Vera Rubin Ridge, NASA’s Curiosity Mars rover has moved to a new part of Mount Sharp. Project Scientist Ashwin Vasavada gives a tour of the rover’s new home in the «clay unit,» as well as other areas scientists are excited to visit. Video Credits: NASA/JPL.


Each region represents a different period in the history of Mount Sharp, which rises about 3 miles (5 kilometers) from the base of Gale Crater. Curiosity’s scientists want to visit these places to learn more about the history of water on the mountain, which slowly dried up as the climate changed.


Understanding how these changes occurred on Mount Sharp may provide new insights into why water — one of the most critical resources for life — disappeared from Mars billions of years ago.



Mars Curiosity selfie. Image Credits: NASA/JPL-Caltech

NASA plans to land astronauts on the Moon by 2024 as a step toward human exploration of Mars. The technologies that will be developed for the Moon will make future robotic and human missions to Mars possible.


For more information about the Curiosity Mars rover, visit: https://mars.nasa.gov/msl/


For more information about NASA’s Mars program, visit: https://mars.nasa.gov/


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


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From canals to craters


ESA — Mars Express Mission patch.


16 May 2019


Mars was once believed to be criss-crossed by a system of irrigation canals – dark troughs that sliced across the planet’s surface, excavated by an intelligent society of thirsty martians. The astronomer who promoted this idea lends his name to the crater shown in this image from ESA’s Mars Express: Lowell crater.



Perspective view of Lowell crater

American astronomer and author Percival Lowell is perhaps best known for popularising this canal theory in the late 1800s and early 1900s; the idea was initially proposed by Italian scientist Giovanni Schiaparelli, who noted the presence of dark lines on Mars in observations from the 1870s. Schiaparelli described these features as canali, later translated not as ‘channels’ or ‘gullies’, but as ‘canals’ – a phrase that hinted at a somewhat more artificial origin.




Lowell crater in context

While these canali were later shown to be an optical illusion as astronomical observations improved immeasurably in quality and precision, the notion of a race of parched, canal-building martians persisted for some time and went on to have a huge influence on the science fiction of the time, perhaps spurred on by the rapid industrialisation – and canal-building – occurring on Earth throughout the 1900s.


Lowell established an observatory in Arizona, USA, purely for the observation of Mars, a planet that had long captured his imagination and interest. Despite his wider astronomical interest in our Solar System – including predictions of a ‘Planet X’ lurking beyond Uranus, later shown to be Pluto – Lowell is most prominently connected to the Red Planet, making the astronomer a fitting namesake for the crater shown in these images from Mars Express.



Plan view of Lowell crater

The data were gathered across seven different spacecraft orbits to create the mosaic; Mars Express’ orbit in recent months allowed several new observations of Lowell crater, which are used alongside older data to form this detailed new view.


Lowell crater is roughly 200 km in diameter and located in a region of Mars known as Aonia Terra, within the planet’s ancient southern highlands. The impact that created it is thought to have taken place between 3.7 and 3.9 billion years ago; it has endured erosion and infilling since. Its crater floor has become covered and flattened by various layers of sediment, and its outer rim is marked by small dunes and gullies.



Topographic view of Lowell crater

The image also highlights a ring of mountains rising up from the crater floor and spanning 90 km across. This so-called ‘peak ring’ is thought to have formed along with the crater. The immense energy of a large impact event causes material to surge upwards before collapsing down again, forming the kind of complex morphology seen here, with an irregular mountain range encircling the crater’s centre, inside the main crater rim.


Such features are also seen in craters here on Earth, and on Venus, Mercury, and the Moon. One notable terrestrial crater that displays this kind of peak ring is Chicxulub crater – famous for its role in the extinction of the dinosaurs some 66 million years ago. Studies and simulations of Chicxulub, which is around the same size as Lowell crater, have shown a peak ring that formed as a huge, unstable central peak later collapsed.



Mars Express

Mars Express has been in orbit around the Red Planet since 2003, and continues to provide a wealth of information about our planetary neighbour.


Related links:


ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA


Mars Express: http://www.esa.int/Our_Activities/Space_Science/Mars_Express


Images, Text, Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO.


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NASA’s MRO Completes 60,000 Trips Around Mars


NASA — Mars Reconnaissance Orbiter (MRO) logo.


May 16, 2019


NASA’s Mars Reconnaissance Orbiter hit a dizzying milestone this morning: It completed 60,000 loops around the Red Planet at 10:39 a.m. PDT (1:39 p.m. EDT). On average, MRO takes 112 minutes to circle Mars, whipping around at about 2 miles per second (3.4 kilometers per second).



Image above: This still from an animation shows NASA’s Mars Reconnaissance Orbiter soaring over Mars. The spacecraft has been in Mars orbit for 13 years, and just completed 60,000 trips around the planet. Image Credits: NASA/JPL-Caltech.


Since entering orbit on March 10, 2006, the spacecraft has been collecting daily science about the planet’s surface and atmosphere, including detailed views with its High Resolution Imaging Science Experiment camera (HiRISE). HiRISE is powerful enough to see surface features the size of a dining room table from 186 miles (300 kilometers) above the surface.


Meanwhile, MRO is watching the daily weather and probing the subsurface for ice, providing data that can influence the designs of future missions that will take humans to Mars.


But MRO isn’t just sending back its own science; it serves in a network of relays that beam data back to Earth from NASA’s Mars rovers and landers. Later this month, MRO will hit another milestone: It will have relayed 1 terabit of data, largely from NASA’s Curiosity rover. If you’ve ever enjoyed one of Curiosity’s selfies or sprawling landscapes or wondered at its scientific discoveries, MRO probably helped make them possible.



«MRO has given scientists and the public a new perspective of Mars,» said Project Manager Dan Johnston at NASA’s Jet Propulsion Laboratory in Pasadena, California, which leads the mission. «We’ve also supported NASA’s fleet of Mars surface missions, allowing them to send their images and discoveries back to scientists on Earth.»


Eyes in the Sky


While rovers and landers can study only their immediate vicinity, orbiters can view wide swaths of the entire planet; MRO can actually target any point on the Martian globe approximately once every two weeks.



HiRISE Spots CO2 Ice Sublimating

Animation above: This series of images shows carbon dioxide ice sublimating (going directly from a solid to a gas) inside a pit at Mars’ south pole. Each frame of the animation was taken by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter. Animation Credits: NASA/JPL-Caltech/University of Arizona.


MRO’s aerial perspective also provides scientists a complementary view of a dynamic planet. As seasons change, they can see avalanches and cloud patterns. HiRISE has imaged CO2 ice sublimating, migrating sand dunes and meteorite strikes reshaping the landscape. With its Mars Climate Sounder instrument and its Mars Color Imager camera, MRO can also study atmospheric events like the massive global dust storm that proved fatal to NASA’s Opportunity rover in 2018.


«Mars is our laboratory,» said MRO Deputy Project Scientist Leslie Tamppari of JPL. «After more than a decade, we’ve collected enough data to formulate and test hypotheses to see how they change or hold up over time.»


Daily Calls to Earth


MRO is one of several orbiters that send data from Mars to Earth each day. The same way MRO is the primary relay for Curiosity, Odyssey (NASA’s longest-lived orbiter) is the primary relay for the agency’s latest Martian inhabitant, InSight. The Mars Atmosphere and Volatile Evolution (MAVEN) orbiter recently started changing its orbit in preparation to cover the Mars 2020 rover’s entry after it lands in February 2021. After data is sent up to an orbiter, it’s beamed to giant antennas at one of three locations around Earth, all of which are part of NASA’s Deep Space Network.


That relay network is now international. The European Space Agency’s Trace Gas Orbiter has been carrying an ever-increasing share of data sent from the surface. And all of these orbiters are preparing for the arrival of ESA’s Rosalind Franklin ExoMars rover, which is scheduled to land the same year as Mars 2020.


Mars Landings


Orbiters like MRO and Odyssey are snap-happy, constantly imaging potential landing sites for future missions. But after a site has been selected and a mission is sent to Mars, orbiters play another critical role.


Before a surface mission can begin conducting science, it has to land safely. Successful landings require clocklike precision so that the spacecraft enters the Martian atmosphere at just the right angle, the parachute opens at the right time and sensors detect the rapidly approaching surface.



Jezero Crater, Mars 2020’s Landing Site

Image above: This image of Jezero Crater on Mars, the landing site for NASA’s Mars 2020 mission, was taken by instruments on NASA’s Mars Reconnaissance Orbiter, which regularly takes images of potential landing sites for future missions. Image Credits: NASA/JPL-Caltech/MSSS/JHU-APL.


MRO and other orbiters serve as black boxes, recording data about each landing, which grow more difficult with the sort of added mass that comes with a mission like Mars 2020. Engineers use the data to design safer missions — which will be key to sending astronauts to Mars. With plans to return astronauts to the surface of the Moon by 2024, NASA is looking ahead at humans exploring the Red Planet, too.


NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate in Washington. The University of Arizona in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. in Boulder, Colorado. Malin Space Science Systems in San Diego, provided and operates MARCI.


Related links:


High Resolution Imaging Science Experiment camera (HiRISE): https://hirise.lpl.arizona.edu/


Deep Space Network: https://deepspace.jpl.nasa.gov/news/


Mars Reconnaissance Orbiter (MRO) Images Gallery: https://mars.nasa.gov/mro/multimedia/images/


For additional information about MRO, visit: http://nasa.gov/mro and  Mars Reconnaissance Orbiter (MRO): http://www.nasa.gov/mission_pages/MRO/main/index.html


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


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2019 May 16 Dark Skies: Turn on the Night Image Credit &…


2019 May 16


Dark Skies: Turn on the Night
Image Credit & Copyright: Jeff Dai (TWAN)


Explanation: Have you ever experienced a really dark night sky? One common and amazing feature is the glowing band of our Milky Way galaxy stretching from horizon to horizon. If you live in or near a big city, though, you might not know this because city lights reflecting off the Earth’s atmosphere could only allow you to see the Moon and a few stars. Today, however, being UNESCO’s International Day of Light, the International Astronomical Union is asking people to Turn on the Night by trying to better understand, and in the future better reduce, light pollution. You can practice even now by going to the main APOD website at NASA and hovering your cursor over the Before image. The After picture that comes up is a panorama of four exposures taken with the same camera and from the same location, showing what happened recently in China when people in Kaihua County decided to turn down many of their lights. Visible in the Before picture are the stars Sirius (left of center) and Betelgeuse, while visible in the After picture are thousands of stars with the arching band of our Milky Way Galaxy. Humanity has lived for millennia under a dark night sky, and connecting to it has importance for both natural and cultural heritage.


∞ Source: apod.nasa.gov/apod/ap190516.html


Recent finds from Tell el-Farcha in the Nile Delta

Research at Tell el-Farcha in the Nile Delta, northern Egypt, has completely changed our understanding of the origins of the Egyptian kingdom. Among other things, one of the oldest breweries in the world and a unique golden statue from about 5 000 years ago was discovered there. This year marks the 20th anniversary of these excavations.











Recent finds from Tell el-Farcha in the Nile Delta
One of the graves discovered at Tell el-Farcha
[Credit: R. Slabonski]

«When we started excavations in Tell el-Farcha, we knew that it was the right place to conduct research, but we were not expecting such spectacular results even in our wildest dreams», said Prof. Krzysztof Ciałowicz from the Institute of Archaeology of the Jagiellonian University in Krakow, who heads the research on this site together with Dr. Marek Chłodnicki from the Archaeological Museum in Poznań, in an interview with the Polish Press Agency.
Tell el-Farcha is three small hillocks located next to the modern village of Gazala. Inside them there are the remains of a settlement, a cemetery and a ceremonial and residential complex dating back more than 5 000 years. Archaeologists have discovered there, among other things, some of the oldest breweries in the world, golden statues showing rulers, bone figurines of people and animals which, according to scientists, are among the most beautiful specimens of art at the time of the formation of the Egyptian state.


«The importance of discovery leads us to believe that this settlement might even have been one of the capitals of the Egyptian kingdom at the end of the fourth millennium. Such a conclusion means that we have to radically change our view of the early history of Egypt», believes Prof. Ciałowicz.











Recent finds from Tell el-Farcha in the Nile Delta
One of two gold figurines discovered at Tell el-Farcha
[Credit: R. Slabonski]

So far, the prevailing opinion among Egyptologists was that the impulse associated with the development of civilization was based on communities in Upper Egypt. «However, it turns out that the level of advancement of peoples in northern Egypt was in no way inferior to the communities in the south», adds Prof. Ciałowicz.
Polish archaeologists were not the first to excavate in Tell el-Farcha. The Italians started research 30 years ago, but they did not bring spectacular findings and abandoned the excavation. «At that time, archaeologists were only a hair’s length away from a deposit of precious figurines from 5,000 years ago, which has already been exposed by our research mission», recalls Dr. Marek Chłodnicki, who also participated in Italian research. The scientist adds that it is important to have patience while excavating. «In our case, spectacular results appeared only after 8 years», he notes.


In Ciałowicz’s opinion, the results of the work of the Polish mission clearly indicate that Egypt still warrants excavation and archaeological research, and in the coming years Poznań and Cracow researchers intend to continue their work at Tell el-Farcha.











Recent finds from Tell el-Farcha in the Nile Delta
The oldest Egyptian mastaba (tomb of a nobleman) made of mud-bricks
was also discovered at Tell el-Farcha [Credit: R. Slabonski]

Scientists have yet to explain the reasons for the collapse of the settlement. This occurred around 2600 BC, when the largest Egyptian pyramids were built, including the Cheops pyramid in Giza. «We suppose that the inhabitants were largely engaged in long-distance trade, and in that period the course of trade routes changed, and these did not pass through Tell el-Farcha anymore,» adds Prof. Ciałowicz.
In the previous years, the scientists carried out geophysical research on the site, which enabled them to penetrate the surface without any physical intervention. Thanks to this research, they have identified several other excavation sites. They hope, among other things, to discover graves from as early as the middle of the fourth millennium BC. So far, according to Dr Chłodnicki’s estimates, less than 10% of the area of the entire prehistoric settlement has been explored.


Prof. Ciałowicz adds that the excavations in Tell el-Farcha must be continued because of the fact that the contemporary buildings threaten the prehistoric remains. «The modern settlement adjacent to the hills continues to grow,» he points out. According to Dr. Chłodnicki, it will take several decades to fully explore Tell el-Farcha. «When I first came here, I didn’t think we would spend more than 5 years in this place», he says.











Recent finds from Tell el-Farcha in the Nile Delta
Assortment of ivory figurines discovered at Tell el-Farcha
[Credit: R. Slabonski]

When archaeologists started excavations at the site, the work was much more time consuming and difficult,» recalls Prof. Ciałowicz. Now, with the technological progress, documenting the results is much faster. «Two decades ago, we drew objects and archaeological profiles on large sheets of paper; now, with the use of electronic devices, the drawings are automatically stored in computers», says the scientist.


As a result, work which a few years ago would have required a few days to complete can now be done in one afternoon.


More information on the Tell el-Farcha excavation is available on the project’s website.


Source: PAP — Science in Poland [May 10, 2019]



TANN



Archive


3D Earth in the making


ESA — GOCE Mission logo.


15 May 2019


A thorough understanding of the ‘solid Earth’ system is essential for deciphering the links between processes occurring deep inside Earth and those occurring nearer the surface that lead to seismic activity such as earthquakes and volcanic eruptions, the rise of mountains and the location of underground natural resources. Thanks to gravity and magnetic data from satellites along with seismology, scientists are on the way to modelling inner Earth in 3D.


Solid Earth refers to the crust, mantle and core. Because these parts of our world are completely hidden from view, understanding what is going on deep below our feet can only be done by using indirect measurements.



Density variations in the crust and upper mantle

New results, based on a paper published recently in Geophysical Journal International and  presented at this week’s Living Planet Symposium, reveal how scientists are using a range of different measurements including satellite data along with seismological models to start producing a global 3D Earth reference model.


The model will make a step change in being able to analyse Earth’s lithosphere, which is the rigid outer shell, and the underlying mantle to understand the link between Earth’s structure and the dynamic processes within.


Juan Carlos Afonso, from Australia’s Macquarie University and Norway’s Centre for Earth Evolution and Dynamics, said, “We are realising the new global model of Earth’s lithosphere and upper mantle by combining  gravity anomalies, geoid height and gravity gradients complemented with seismic, thermal and rock information.


Wolfgang Szwillus from Kiel University, added, “Data from ESA’s GOCE satellite mission served as input for the inversion. It is the first time that gravity gradients have been inverted on a global scale in such an integrated framework.”


While this is just a first step, 3D Earth offers tantalising insights into the deep structure of our world. For example, the new models of the thickness of the crust and the lithosphere are important for unexplored continents like Antarctica.




 GOCE in orbit

Jörg Ebbing from Kiel University, noted, “This is just a first step so we have more work to do, but we plan to release the 3D Earth models in 2020.”


The 3D Earth research, which involves scientists from nine institutes in six European countries, is funded through ESA’s Science for Society programme. ESA’s GOCE gravity mission and Swarm magnetic field mission are key to this research.


We are changing our natural world faster than at any other time in history. Understanding the intricacies of how Earth works as a system and the impact that human activity is having on natural processes are huge environmental challenges. Satellites are vital for taking the pulse of our planet, delivering the information we need to understand and monitor our precious world, and for making decisions to safeguard our future. Earth observation data is also key to a myriad of practical applications to improve everyday life and to boost economies. This week we focus on the world’s biggest conference on Earth observation where thousands of scientists and data users discuss the latest results and look to the future of Earth observation.


Related links:


Living Planet Symposium: http://www.esa.int/Our_Activities/Observing_the_Earth/Living_Planet_Symposium


Geophysical Journal International: https://academic.oup.com/gji/article-abstract/217/3/1602/5370085?redirectedFrom=fulltext


3D Earth: http://www.3dearth.uni-kiel.de/


GOCE: http://www.esa.int/Our_Activities/Observing_the_Earth/GOCE


Animation, Image, Text, Credits: ESA/Density values from LithoRef18 (Afonso et al.) and gravity gradients from Bouman et al. (2016)/AOES Medialab.


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Tug-of-war drives magnetic north sprint


ESA — SWARM Mission logo.


15 May 2019


As far as we know, Earth’s magnetic north has always wandered, but it has recently gained new momentum and is making a dash towards Siberia at a pace not seen before. While this has some practical implications, scientists believe that this sprint is being caused by tussling magnetic blobs deep below our feet.


Unlike our geographic North Pole, which is in a fixed location, magnetic north wanders. This has been known since it was first measured in 1831, and subsequently mapped drifting slowly from the Canadian Arctic towards Siberia.



Magnetic North Pole 1840–2019

One of the practical consequences of this is that the World Magnetic Model has to be updated periodically with the pole’s current location. The model is vital for many navigation systems used by ships, Google maps and smartphones, for example.


One of the many areas of research using information from Swarm focuses on explaining why the pole has picked up such a pace – and a subject being discussed at this week’s Living Planet Symposium.


Between 1990 and 2005 magnetic north accelerated from its historic speed of 0–15 km a year, to its present speed of 50–60 km a year. In late October 2017, it crossed the international date line, passing within 390 km of the geographic pole, and is now heading south.


In fact, recently, the World Magnetic Model had to be updated urgently because of the speed at which the pole is moving.



Space compasses

ESA’s Swarm mission is not only being used to keep track of magnetic north, but scientists are using its data to measure and untangle the different magnetic fields that stem from Earth’s core, mantle, crust, oceans, ionosphere and magnetosphere.


Our magnetic field exists because of an ocean of superheated, swirling liquid iron that makes up the outer core. Like a spinning conductor in a bicycle dynamo, this moving iron creates electrical currents, which in turn generate our continuously changing magnetic field.


Tracking changes in the magnetic field can, therefore, tell researchers how the iron in the core moves.


Phil Livermore, from the University of Leeds in the UK, said, “Several theories have been proposed to explain this behaviour but, since they rely upon changes in the small-scale magnetic field, they cannot explain the recent trajectory of the pole.


“Using data collected over two decades by satellites, including ESA’s Swarm trio, we can see that the position of the north magnetic pole is determined largely by a balance, or tug-of-war, between two large lobes of negative magnetic flux at the boundary between Earth’s core and mantle under Canada and Siberia.”



Magnetic north on the move

Research is showing that changes in the pattern of core flow between 1970 and 1999 elongated the Canadian lobe, significantly weakening its signature on Earth’s surface, causing the pole to accelerate towards Siberia.


Simple models taking account of this process and describing future geomagnetic change predict that over the next decade the north magnetic pole will continue on its current trajectory and will travel a further 390–660 km towards Siberia.



Swarm

We are changing our natural world faster than at any other time in history. Understanding the intricacies of how Earth works as a system and the impact that human activity is having on natural processes are huge environmental challenges. Satellites are vital for taking the pulse of our planet, delivering the information we need to understand and monitor our precious world, and for making decisions to safeguard our future. Earth observation data is also key to a myriad of practical applications to improve everyday life and to boost economies. This week we focus on the world’s biggest conference on Earth observation where thousands of scientists and data users discuss the latest results and look to the future of Earth observation.


Related links:


Living Planet Symposium: http://www.esa.int/Our_Activities/Observing_the_Earth/Living_Planet_Symposium


DTU Space: http://www.space.dtu.dk/english


University of Leeds – School of Earth and Environment: https://environment.leeds.ac.uk/see


Swarm: http://www.esa.int/Our_Activities/Observing_the_Earth/Swarm


Images, Video, Text, Credits: ESA/ATG Medialab/DTU Space/geoGraphics.


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