пятница, 10 мая 2019 г.

A new filter to better map the dark universe

The earliest known light in our universe, known as the cosmic microwave background, was emitted about 380,000 years after the Big Bang. The patterning of this relic light holds many important clues to the development and distribution of large-scale structures such as galaxies and galaxy clusters.











A new filter to better map the dark universe
Just as a wine glass distorts an image showing temperature fluctuations in the cosmic microwave background in this photo
 illustration, large objects like galaxy clusters and galaxies can similarly distort this light to produce lensing effects
[Credit: Emmanuel Schaan and Simone Ferraro/Berkeley Lab]

Distortions in the cosmic microwave background (CMB), caused by a phenomenon known as lensing, can further illuminate the structure of the universe and can even tell us things about the mysterious, unseen universe — including dark energy, which makes up about 68 percent of the universe and accounts for its accelerating expansion, and dark matter, which accounts for about 27 percent of the universe.


Set a stemmed wine glass on a surface, and you can see how lensing effects can simultaneously magnify, squeeze, and stretch the view of the surface beneath it. In lensing of the CMB, gravity effects from large objects like galaxies and galaxy clusters bend the CMB light in different ways. These lensing effects can be subtle (known as weak lensing) for distant and small galaxies, and computer programs can identify them because they disrupt the regular CMB patterning.


There are some known issues with the accuracy of lensing measurements, though, and particularly with temperature-based measurements of the CMB and associated lensing effects.


While lensing can be a powerful tool for studying the invisible universe, and could even potentially help us sort out the properties of ghostly subatomic particles like neutrinos, the universe is an inherently messy place.


And like bugs on a car’s windshield during a long drive, the gas and dust swirling in other galaxies, among other factors, can obscure our view and lead to faulty readings of the CMB lensing.


There are some filtering tools that help researchers to limit or mask some of these effects, but these known obstructions continue to be a major problem in the many studies that rely on temperature-based measurements.


The effects of this interference with temperature-based CMB studies can lead to erroneous lensing measurements, said Emmanuel Schaan, a postdoctoral researcher and Owen Chamberlain Postdoctoral Fellow in the Physics Division at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).


«You can be wrong and not know it,» Schaan said. «The existing methods don’t work perfectly — they are really limiting.»


To address this problem, Schaan teamed up with Simone Ferraro, a Divisional Fellow in Berkeley Lab’s Physics Division, to develop a way to improve the clarity and accuracy of CMB lensing measurements by separately accounting for different types of lensing effects.


«Lensing can magnify or demagnify things. It also distorts them along a certain axis so they are stretched in one direction,» Schaan said.











A new filter to better map the dark universe
A set of cosmic microwave background images with no lensing effects (top row) and with exaggerated cosmic microwave
background lensing effects (bottom row) [Credit: Wayne Hu and Takemi Okamoto/University of Chicago]

The researchers found that a certain lensing signature called shearing, which causes this stretching in one direction, seems largely immune to the foreground «noise» effects that otherwise interfere with the CMB lensing data. The lensing effect known as magnification, meanwhile, is prone to errors introduced by foreground noise. Their study, published  in the journal Physical Review Letters, notes a «dramatic reduction» in this error margin when focusing solely on shearing effects.


The sources of the lensing, which are large objects that stand between us and the CMB light, are typically galaxy groups and clusters that have a roughly spherical profile in temperature maps, Ferraro noted, and the latest study found that the emission of various forms of light from these «foreground» objects only appears to mimic the magnification effects in lensing but not the shear effects.


«So we said, ‘Let’s rely only on the shear and we’ll be immune to foreground effects,'» Ferraro said. «When you have many of these galaxies that are mostly spherical, and you average them, they only contaminate the magnification part of the measurement. For shear, all of the errors are basically gone.»


He added, «It reduces the noise, allowing us to get better maps. And we’re more certain that these maps are correct,» even when the measurements involve very distant galaxies as foreground lensing objects.


The new method could benefit a range of sky-surveying experiments, the study notes, including the POLARBEAR-2 and Simons Array experiments, which have Berkeley Lab and UC Berkeley participants; the Advanced Atacama Cosmology Telescope (AdvACT) project; and the South Pole Telescope — 3G camera (SPT-3G). It could also aid the Simons Observatory and the proposed next-generation, multilocation CMB experiment known as CMB-S4 — Berkeley Lab scientists are involved in the planning for both of these efforts.


The method could also enhance the science yield from future galaxy surveys like the Berkeley Lab-led Dark Energy Spectroscopic Instrument (DESI) project under construction near Tucson, Arizona, and the Large Synoptic Survey Telescope (LSST) project under construction in Chile, through joint analyses of data from these sky surveys and the CMB lensing data.


Increasingly large datasets from astrophysics experiments have led to more coordination in comparing data across experiments to provide more meaningful results. «These days, the synergies between CMB and galaxy surveys are a big deal,» Ferraro said.


In this study, researchers relied on simulated full-sky CMB data. They used resources at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC) to test their method on each of the four different foreground sources of noise, which include infrared, radiofrequency, thermal, and electron-interaction effects that can contaminate CMB lensing measurements.


The study notes that cosmic infrared background noise, and noise from the interaction of CMB light particles (photons) with high-energy electrons have been the most problematic sources to address using standard filtering tools in CMB measurements. Some existing and future CMB experiments seek to lessen these effects by taking precise measurements of the polarization, or orientation, of the CMB light signature rather than its temperature.


«We couldn’t have done this project without a computing cluster like NERSC,» Schaan said. NERSC has also proved useful in serving up other universe simulations to help prepare for upcoming experiments like DESI.


The method developed by Schaan and Ferraro is already being implemented in the analysis of current experiments’ data. One possible application is to develop more detailed visualizations of dark matter filaments and nodes that appear to connect matter in the universe via a complex and changing cosmic web.


The researchers reported a positive reception to their newly introduced method.


«This was an outstanding problem that many people had thought about,» Ferraro said. «We’re happy to find elegant solutions.»


Author: Glenn Roberts Jr. | Source: DOE/Lawrence Berkeley National Laboratory [May 08, 2019]




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Star formation burst in the Milky Way 2-3 billion years ago

A team led by researchers of the Institute of Cosmos Sciences of the University of Barcelona (ICCUB, UB-IEEC) and the Besançon Astronomical Observatory have found, analysing data from the Gaia satellite, that a severe star formation burst occurred in the Milky Way about to and three thousand million years ago. In this process, more than 50 % of the stars that created the galactic disc may have been born. There results come from the combination of the distances, colors and magnitude of the stars that were measured by Gaia with models that predict their distribution in our Galaxy. The study has been published in the journal Astronomy & Astrophysics.











Star formation burst in the Milky Way 2-3 billion years ago
The region of the stellar formation Rho Ophiuchi observed by ESA Gaia satellite. The shining dots are stellar clusters
with the massive and youngest stars of the region. The dark filaments track the gas and dust distribution, where
 the new stars are born. This is not a conventional photographic image but the result of the integration
of all the received radiation by the satellite during the 22 months of continuous measurements
through different filters on the spacecraft [Credit: ESA/Gaia/DPAC]

Just like a flame fades when there is no gas in the cylinder, the rhythm of the stellar formation in the Milky Way, fuelled by the gas that was deposited, should decrease slowly and in a continuous way until using up the existing gas. The results of the study show that, although this was the process that took place over the first 4,000 million years of the disc formation, a severe star formation burst, or «stellar baby boom» -as stated in the article published in the Nature Research Highlights-, inverted this trend. The merging with a satellite galaxy of the Milky Way, which is rich in gas, could have administrated new fuel and reactivate the process of stellar formation, in a similar way to when a gas cylinder is changed. This mechanism would explain the distribution of distances, ages and masses that are estimated from the data taken from the European Space Agency Gaia satellite.
«The time scale of this star formation burst together with the great amount of stellar mass involved in the process, thousands of millions of solar mass, suggests the disc of our Galaxy did not have a steady and paused evolution, it may have suffered an external perturbation that began about five billion years ago», said Roger Mor, ICCUB researcher and first signer of the article.


«We have been able to find this out due having -for the first time- precise distances for more than three million stars in the solar environment», says Roger Mor. «Thanks to these data -he continues- we could discover the mechanisms that controlled the evolution more than 8-10 billion years ago in the disc of our Galaxy, which is not more than the bright band we see in the sky on a dark night and with no light pollution». Like in many research fields these days, these findings have been possible thanks to the availability of the combination of a great amount of unprecedented precision data, and the availability of a great amount of hours in computing in the computer facilities funded by the FP7 GENIUS European project (Gaia European Project for Improved data User Services) -in the Center for Scientific and Academic Services of Catalonia (CSUC).


Cosmologic models predict our galaxy would have been growing due the merging with other galaxies, a fact that has been stated by other studies using Gaia data. One of these merges could be the cause of the severe star formation burst that was detected in this study.


«Actually, the peak of star formation is so clear, unlike what we predicted before having data from Gaia, that we thought necessary to treat its interpretation together with experts on cosmological evolution of external galaxies», notes Francesca Figuerars, lecturer at the Department of Quantum Physics and Astrophysics of the UB, ICCUB member and signer of the article.


According to the expert on simulations of galaxies similar to the Milky Way, Santi Roca-Fàbrega -from the Complutense University of Mardid and also signer of the article, «the obtained results match with what the current cosmological models predict, and what is more -he continues- our Galaxy seen from Gaia’s eyes is an excellent cosmological laboratory where we can test and confront models at a bigger scale in the universe».


Gaia mission until 2020


This study has been conducted with the second release of the Gaia mission, which was published a year ago, on April 25, 2018. Xavier Luri, director of ICCUB and also signer of the article states: «The role of scientists and engineers of the UB has been essential so that the scientific community enjoys the excellent quality of data from the Gaia release».


More than 400 scientists and engineers from around Europe are part of the consortium in charge of preparing and validating these data. «Their collective work brought the international scientific community a release that is making us rethink many of the existent scenarios on the origins and evolution of our galaxy», notes Luri.


In one year, more than 1,200 peer review articles published in journals show the before and after Gaia in almost all fields of astrophysics, from the recent detection of new stellar clusters, new asteroids, to the affirmation of the star extragalactic origin in our Galaxy, going through the calculus of the Milky Way mass and the findings that show compact stars end up slowly solidified.


«The satellite continues to operate optimally and this July the five nominal years of scientific operation will be completed», notes Carme Jordi, UB researcher and member of the Gaia Science Team, the scientific advisor body of the European Space Agency (ESA) for this mission. ESA has approved of the extension of the mission until late 2020 -one more year than expected- and engineering teams estimate that there is enough fuel to continue working until 2024. «There is no doubt this mission has passed a technological unprecedented challenge in space missions of all time», concludes Carme Jordi.


Source: University of Barcelona [May 08, 2019]



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Radioactive carbon from nuclear bomb tests found in deep ocean trenches

Radioactive carbon released into the atmosphere from 20th-century nuclear bomb tests has reached the deepest parts of the ocean, new research finds.











Radioactive carbon from nuclear bomb tests found in deep ocean trenches
The 37 kiloton ‘Priscilla’ nuclear test, detonated at the Nevada Test Site in 1957
[Credit: US Department of Energy]

A new study in AGU’s journal Geophysical Research Letters finds the first evidence of radioactive carbon from nuclear bomb tests in muscle tissues of crustaceans that inhabit Earth’s ocean trenches, including the Mariana Trench, home to the deepest spot in the ocean.


Organisms at the ocean surface have incorporated this «bomb carbon» into the molecules that make up their bodies since the late 1950s. The new study finds crustaceans in deep ocean trenches are feeding on organic matter from these organisms when it falls to the ocean floor. The results show human pollution can quickly enter the food web and make its way to the deep ocean, according to the study’s authors.


«Although the oceanic circulation takes hundreds of years to bring water containing bomb [carbon] to the deepest trench, the food chain achieves this much faster,» said Ning Wang, a geochemist at the Chinese Academy of Sciences in Guangzhou, China, and lead author of the new study.


«There’s a very strong interaction between the surface and the bottom, in terms of biologic systems, and human activities can affect the biosystems even down to 11,000 meters, so we need to be careful about our future behaviors,» said Weidong Sun, a geochemist at the Chinese Academy of Sciences in Qingdao, China, and co-author of the new study. «It’s not expected, but it’s understandable, because it’s controlled by the food chain.»


The results also help scientists better understand how creatures have adapted to living in the nutrient-poor environment of the deep ocean, according to the authors. The crustaceans they studied live for an unexpectedly long time by having extremely slow metabolisms, which the authors suspect may be an adaptation to living in this impoverished and harsh environment.


Creating radioactive particles


Carbon-14 is radioactive carbon that is created naturally when cosmic rays interact with nitrogen in the atmosphere. Carbon-14 is much less abundant than non-radioactive carbon, but scientists can detect it in nearly all living organisms and use it to determine the ages of archeological and geological samples.


Thermonuclear weapons tests conducted during the 1950s and 1960s doubled the amount of carbon-14 in the atmosphere when neutrons released from the bombs reacted with nitrogen in the air. Levels of this «bomb carbon» peaked in the mid-1960s and then dropped when atmospheric nuclear tests stopped. By the 1990s, carbon-14 levels in the atmosphere had dropped to about 20 percent above their pre-test levels.


This bomb carbon quickly fell out of the atmosphere and mixed into the ocean surface. Marine organisms that have lived in the decades since this time have used bomb carbon to build molecules within their cells, and scientists have seen elevated levels of carbon-14 in marine organisms since shortly after the bomb tests began.


Life at the bottom of the sea


The deepest parts of the ocean are the hadal trenches, those areas where the ocean floor is more than 6 kilometers (4 miles) below the surface. These areas form when one tectonic plate subducts beneath another. Creatures that inhabit these trenches have had to adapt to the intense pressures, extreme cold, and lack of light and nutrients.











Radioactive carbon from nuclear bomb tests found in deep ocean trenches
Hirondellea gigas, a type of amphipod that lives in the Mariana Trench
[Credit: Daiju Azuma]

In the new study, researchers wanted to use bomb carbon as a tracer for organic material in hadal trenches to better understand the organisms that live there. Wang and her colleagues analyzed amphipods collected in 2017 from the Mariana, Mussau, and New Britain Trenches in the tropical West Pacific Ocean, as far down as 11 kilometers (7 miles) below the surface. Amphipods are a type of small crustacean that live in the ocean and get food from scavenging dead organisms or consuming marine detritus.
Surprisingly, the researchers found carbon-14 levels in the amphipods’ muscle tissues were much greater than levels of carbon-14 in organic matter found in deep ocean water. They then analyzed the amphipods’ gut contents and found those levels matched estimated carbon-14 levels from samples of organic material taken from the surface of the Pacific Ocean. This suggests the amphipods are selectively feeding on detritus from the ocean surface that falls to the ocean floor.


Adapting to the deep ocean environment


The new findings allow researchers to better understand the longevity of organisms that inhabit hadal trenches and how they have adapted to this unique environment.


Interestingly, the researchers found the amphipods living in these trenches grow larger and live longer than their counterparts in shallower waters. Amphipods that live in shallow water typically live for less than two years and grow to an average length of 20 millimeters (0.8 inches). But the researchers found amphipods in the deep trenches that were more than 10 years old and had grown to 91 millimeters (3.6 inches) long.


The study authors suspect the amphipods’ large size and long life are likely the byproducts of their evolution to living in the environment of low temperatures, high pressure and a limited food supply. They suspect the animals have slow metabolisms and low cell turnover, which allows them to store energy for long periods of time. The long life time also suggests pollutants can bioaccumulate in these unusual organisms.


«Besides the fact that material mostly comes from the surface, the age-related bioaccumulation also increases these pollutant concentrations, bringing more threat to these most remote ecosystems,» Wang said.


The new study shows deep ocean trenches are not isolated from human activities, Rose Cory, an associate professor of earth and environmental sciences at the University of Michigan who was not involved in the new research, said in an email. The research shows that by using «bomb» carbon, scientists can detect the fingerprint of human activity in the most remote, deepest depths of the ocean, she added.


The authors also use «bomb» carbon to show that the main source of food for these organisms is carbon produced in the surface ocean, rather than more local sources of carbon deposited from nearby sediments, Cory said. The new study also suggests that the amphipods in the deep trenches have adapted to the harsh conditions in deep trenches, she added.


«What is really novel here is not just that carbon from the surface ocean can reach the deep ocean on relatively short timescales, but that the ‘young’ carbon produced in the surface ocean is fueling, or sustaining, life in the deepest trenches,» Cory said.


Source: American Geophysical Union [May 08, 2019]



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2019 May 10 Halley Dust and Milky Way Image Credit &…


2019 May 10


Halley Dust and Milky Way
Image Credit & Copyright: Gang Li


Explanation: Grains of cosmic dust streaked through the mostly moonless night skies of May 7. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids. Though it was made about a day after the shower’s predicted maximum, this composite image still captures 20 meteors in exposures taken over a 2 hour period, registered on a background exposure of the sky. The meteor trails point back to the shower radiant near eponymous faint star Eta Aquarii close to the horizon, seen from 100 kilometers south of Sydney Australia. Known for speed, Eta Aquarid meteors move fast, entering the atmosphere at about 66 kilometers per second. Brilliant Jupiter shines near the central bulge of the Milky Way high above the horizon. The Southern Cross is just tucked in to the upper right corner of the frame.


∞ Source: apod.nasa.gov/apod/ap190510.html


Meteor Activity Outlook for May 11-18, 2019

Meteor over Taos, NM – April, 2 2019 by Mike Lewinski licensed under CC BY 2.0
Sony ILCE-6300, ƒ/3.5, 16.0 mm, 25s, ISO3200

During this period the moon reaches its first quarter phase on Saturday May 11th. At this time the half-illuminated moon is present in the evening sky and does not set until 3-4am as seen from mid-northern latitudes. As the week progresses the window of dark skies between moonset and dawn will shrink until it disappears by Wednesday May 15th. The estimated total hourly meteor rates for evening observers this week is near 2 for those viewing from the northern hemisphere and 3 for those located south of the equator. For morning observers the estimated total hourly rates should be near 11 as seen from mid-northern latitudes (45N) and 20 as seen from tropical southern locations (25S). The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Evening rates are reduced by moonlight during this period. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brightest meteors will be visible from such locations.


The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning May 11/12. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.





Radiant Positions at 10:00pm LDST


Radiant Positions at 10:00pm Local Daylight Saving Time






Radiant Positions at 01:00 LDST


Radiant Positions at 1:00am Local Daylight Saving Time






Radiant Positions at 04:00 LDST


Radiant Positions at 4:00am Local Daylight Saving Time





These sources of meteoric activity are expected to be active this week.


.


The tau Herculids (TAH) are an irregular shower not active every year. They are best known for being associated with comet Schwassmann-Wachmann 3 and the strong display seen in 1930. Due to recent activity from the comet, this shower could produce more activity in the upcoming decade. The Earth could start encountering particles from Schwassmann-Wachmann 3 around May 14. On that date the radiant would lie near 14:24 (216) +35. This area of the sky is located in western Bootes, 4 degrees southwest of the 3rd magnitude star known as Seginus (gamma Bootis). This is not that close to the star tau Herculis, for which this shower is named. Apparently the discoverers of this display placed the radiant further east toward Corona Borealis and Hercules. This area of the sky is best placed near midnight local daylight saving time (LDST), when it lies high overhead for observers located in mid-northern latitudes. With an entry velocity of 15 km/sec., the average tau Herculid meteor would be of very slow velocity.


The center of the large Anthelion (ANT) radiant is currently located at 16:12 (243) -22. This position lies in northwestern Scorpius, 2 degrees southeast of the 3rd magnitude star known as Acrab (beta Scorpii). Due to the large size of this radiant, Anthelion activity may also appear from eastern Libra, southern Ophiuchus as well as northwestern Scorpius. This radiant is best placed near 0200 local Daylight Saving Time (LDST), when it lies on the meridian and is located highest in the sky. Rates at this time should be near 2 per hour as seen from mid-northern latitudes (45 N) and 3 per hour as seen from the southern tropics (S 25) . With an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow velocity.


The eta Lyrids (ELY) are active from May 6-13 with maximum activity occurring on the 11th. The radiant is currently located at 19:24 (291) +44. This area of the sky is located in northeastern Lyra, 4 degrees northeast of the 4th magnitude star known as eta Lyrae. This radiant is best placed during the last hour before dawn when it lies highest above the horizon in a dark sky. Current rates are expected to be 1 as seen from the northern hemisphere and less than 1 as seen from south of the equator. These meteors are not well seen from locations south of the equator as the radiant does not rise very high into the northern sky. With an entry velocity of 44 km/sec., the average meteor from this source would be of medium velocity.


The Theta2 Sagittariids (TTS) are a new discovery of the IMO video network using cameras located in Australia. These meteors are active from May 10-15, which maximum activity occurring on the 14th. At maximum the radiant lies near the position of 20:04 (301) -33. This area of the sky lies in a rather blank area of southeastern Sagittarius, 2 degrees north of the 4th magnitude star known as theta 2 Sagittarii. The radiant is best placed just before the break of dawn when the radiant lies highest in the sky. While Theta 2 Sagittariid meteors can be seen in both hemispheres, the south is favored as the radiant lies higher in their sky. Hourly rates are expected to be less than 1 no matter your location. At 67km/sec. the Theta 2 Sagittariids would produce meteors of swift velocity.


The eta Aquariids (ETA) are particles from Halley’s Comet, produced in Earth-crossing orbits many centuries ago. The radiant is currently located at 22:51 (343) +01. This area of the sky is located in eastern Aquarius, 3 degrees east of the 4th magnitude star known as eta Aquarii. The radiant does not rise until 2-3am local LDST so these meteors cannot be seen during the evening hours. The best time to view this activity is during the hour before the start of morning twilight, when the radiant lies highest in a dark sky. With the radiant low in the east it would be best to face halfway up in the sky in that same direction. Rates should be near 3 per hour as seen from mid-northern latitudes and 7 per hour as seen from the southern tropics. With an entry velocity of 66 kilometers per second, a majority of these meteors will appear to move swiftly with a high percentage of the bright meteors leaving persistent trains. Surprisingly, this shower produces very few fireballs.


As seen from the mid-northern hemisphere (45N) one would expect to see approximately 5 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 1 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 9 per hour as seen from rural observing sites and 2 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Evening rates are reduced due to bright moonlight.


The list below offers the information from above in tabular form. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.


 




































































SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS
RA (RA in Deg.) DEC Km/Sec Local Daylight Saving Time North-South
tau Herculids (TAH) Jun 03 14:24 (216) +35 15 01:00 <1 – <1 III
Anthelions (ANT) 16:12 (243) -22 30 02:00 2 – 3 II
eta Lyrids (ELY) May 11 19:24 (291) +44 44 05:00 1 – <1 II
Theta2 Sagittariids May 15 20:04 (301) -33 67 06:00 <1 – <1 II
eta Aquariids (ETA) May 07 22:51 (343) +01 66 09:00 3 – 7 I

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Tourmaline on Albite | #Geology #GeologyPage #Mineral Locality:…


Tourmaline on Albite | #Geology #GeologyPage #Mineral


Locality: Pederneira Mine, São José da Safira, Doce valley, Minas Gerais, Brazil


Size: 3.8 x 3.3 x 2.1 cm


Photo Copyright © Saphira Minerals


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Halite & Selenite | #Geology #GeologyPage…


Halite & Selenite | #Geology #GeologyPage #Mineral


Locality: Thuringian Forest, Thuringia, Germany


Size: 5.9 × 3.9 × 2.4 cm


Photo Copyright © Viamineralia /e-rocks. com


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It was always going to be this way

The native peoples of the East Baltic — Estonians, Latvians and Lithuanians — are genetically alike and their paternal gene pools are dominated by the same two Y-chromosome haplogroups: R1a and N3a.
Linguistically, however, Estonians are a world apart from Latvians and Lithuanians. That’s because the Estonian language belongs to the Uralic language family, which has an obvious North Eurasian character. On the other hand, Latvian and Lithuanian are both classified as Indo-European languages, along with the vast majority of other European languages.
The Uralic and Indo-European language families may or may not descend from the same ancestral tongue, but even if they do, their relationship is very distant.
So how is it that Estonians came to speak a Uralic language? As far back as I can remember, the basic explanation accepted by most people was that Uralic speech arrived in what is now Estonia and neighboring Finland during the Bronze Age with migrants, or perhaps invaders, rich in N3a from somewhere around the Ural Mountains. Conversely, Latvians and Lithuanians were generally assumed to have retained the Indo-European speech of their R1a-rich forefathers from the Pontic-Caspian steppe, who colonized the East Baltic and surrounds during the Late Neolithic.
Ancient DNA has now uncannily corroborated these theories (for instance, see Mittnik et al. 2018 and, published today, Saag et al. 2019). All it took was a handful of samples from a few relevant sites. I think that’s awesome; I love it when sensible, long-standing hypotheses are validated by cutting edge science.
I’ll have a lot more to say about the spread of Uralic languages and Uralian genes to the East Baltic when I get my hands on the genotype data from the new Saag et al. paper. I also have a post coming soon about the Nordic Bronze Age. Stay tuned.



See also…
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…
Corded Ware people =/= Proto-Uralics (Tambets et al. 2018)
Inferring the linguistic affinity of long dead and non-literate peoples: a multidisciplinary approach
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3 … 2 … 1… ALOHA!Sometimes in space, you have to set your clocks…


3 … 2 … 1… ALOHA!


Sometimes in space, you have to set your clocks to island time and gather for a good Hawaiian shirt day. In this 2001 #TBT, Expedition Two and STS-100 crew members gather for a group photo with a pre-set digital still camera.


Clockwise from the 12 o’clock point in the circle are Kent V. Rominger, Yuri V. Lonchakov, Yury V. Usachev, Umberto Guidoni, James S. Voss, Jeffrey S. Ashby, Scott E. Parazynski, John L. Phillips and Chris A. Hadfield, with Susan J. Helms at center. Usachev, Helms and Voss are members of three Expedition Two crew, with the other seven serving as the STS-100 crew on the Space Shuttle Endeavour. Usachev and Lonchakov represent Rosaviakosmos; Guidoni is associated with the European Space Agency (ESA); and Hadfield is from the Canadian Space Agency (CSA).


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Scholars investigate whole quarter of ancient Petra

A team of scholars involved in the North-Eastern Petra Project (NEPP) investigated for the first time a whole quarter of the ancient city and not merely a single building.











Scholars investigate whole quarter of ancient Petra
The city-centre of Petra as seen from Umm al-Biyara [Credit: A. Barmasse/NEPP]

The idea was to identify remaining structures and their interrelations, said Marco Dehner, a German scholar who completed his studies in archaeology and ancient history at Berlin’s Humboldt University.
“A first hypothesis deals with the idea that this area, indeed, could have been served as a sort of palatial complex or Basileia,” said Dehner, adding that the results show that this area, between the Wadi Musa in the south, Wadi Mataha to the west and north and the Al Khubta massive to the east, is a unique accumulation of buildings and structures of very high standard in Petra, which are somehow separated from the rest of the city centre.











Scholars investigate whole quarter of ancient Petra
View from Jabal Al Madhbah [Credit: Marco Dehner/NEPP]

According to Dehner, the most important artefacts documented during the investigations were architectural elements of high quality from the identified structures.
“Those findings seem to confirm a first building phase in the end of the 1st century BC and the beginning of the 1st century AD. The project was mainly undertaken as a survey, no more special finds could be recorded so far,” he added.











Scholars investigate whole quarter of ancient Petra
Temple of the Winged Lions pathway facing south, Great Temple in the distance
[Credit: TWL CRM]

“In addition to the monumental temples and buildings in the city centre as well as some private buildings on ez-Zantur, the largest number of architectural blocks such as capitals, column drums, column bases, fragments of pediments, architraves [chief beams] and cornices [horizontal decorative moulding] could be documented on the surface in the NEPP area.”
Even without excavation, clear statements about the monumental appearance of some of the buildings can be made, the historian said, noting that the study on single architectural elements he is conducting is the first comprehensive one of elements of “free-standing architecture, as it is coming from surveys and excavations in Petra”.











Scholars investigate whole quarter of ancient Petra
Recently conserved walls in the SW Quadrant. Facing east
[Credit: TWL CRM]

The results of the NEPP are also a perfect starting point for a better understanding of construction processes of free-standing buildings in Petra and to compare them with results from other areas, he said.
“As can also be observed in other areas of Petra, the local sandstone was mainly used for the production of structural elements such as ashlars or column drums, but also for individual building elements with a decorative character. This material was usually added only by limestone, which could also be quarried in relative proximity to the construction site in the area of today’s Wadi Musa,” Dehner said.











Scholars investigate whole quarter of ancient Petra
The Lapidarium — Architectural Gallery at the Temple of the Winged Lions
[Credit: TWL CRM]

He also explained that the individual sandstone blocks used during the construction did not exceed a size of about 100x50x40cm, and were usually of smaller size (90x40x40cm or 60x30x30cm) he claimed, which points to a certain level of standardisation. “The masonry technique is comparable to that of the other buildings in Petra, namely the Temple of the Winged Lions, the Qasral-Bint, the Great Temple and ez-Zantur IV.”


“The size of the used blocks meant that individual elements, such as pediments, architraves or cornices terminating in a sima [upturned edge of a roof], had to be composed of several blocks of sandstone, as the original material often did not allow an element of a certain size to be made from a single block. As a result, the Nabataeans seem to have optimised their construction processes very economically and standardised the manufacturing processes in their sequence.”


Author: Saeb Rawashdeh | Source: The Jordan Times [May 06, 2019]



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More on First hominins on the Tibetan Plateau were Denisovans

The Tibetan Plateau, as Earth’s «Third Pole,» was reported to be first occupied by modern humans probably armed with blade technology as early as 40 ka BP. However, no earlier hominin groups had been found or reported on the Tibetan Plateau until a recent study was published by Chinese researchers.











More on First hominins on the Tibetan Plateau were Denisovans
A virtual reconstruction of the mandible [Credit: Jean-Jacques Hubrin]

A joint research team led by CHEN Fahu from the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences and ZHANG Dongju from the Lanzhou University reported their studies on a human mandible found in Xiahe, on the Northeastern Tibetan Plateau. The findings were published in Nature.
The researchers found that the mandible came from an individual who belonged to a population closely related to the Denisovans first found in Siberia. This population occupied the Tibetan Plateau in the Middle Pleistocene and adapted to this low-oxygen environment long before the arrival of modern Homo sapiens in the region.


So far, Denisovans are only known from a small collection of fossil fragments from Denisova Cave in Siberia. Traces of Denisovan DNA are found in present-day Asian, Australian and Melanesian populations, suggesting that these ancient hominins may have once been widespread.











More on First hominins on the Tibetan Plateau were Denisovans
The Xiahe mandible, only represented by its right half, was found in 1980 in Baishiya Karst Cave
[Credit: © Dongju Zhang, Lanzhou University]

This study confirms for the first time that Denisovans not only lived in East Asia but also on the high-altitude Tibetan Plateau. It also indicates that the previously found possible introgression of Denisovan DNA (EPAS1) into modern Tibetans and Sherpas, who mainly live on the high-altitude Tibetan Plateau and surrounding regions today, is probably derived or inherited locally on Tibetan Plateau from Xiahe hominin represented by this Xiahe mandible.
The reported Xiahe mandible was found on the Tibetan Plateau in the Baishiya Karst Cave in Xiahe, China. Researchers managed to extract collagen from one of the molars, which they then analysed using ancient protein analysis. Ancient protein data showed that the Xiahe mandible belonged to a hominin population closely related to the Denisovans from Denisova Cave.


The robust primitive shape of the mandible and the very large molars still attached to it suggest that this mandible once belonged to a Middle Pleistocene hominin sharing anatomical features with Neandertals and specimens from the Denisova Cave.











More on First hominins on the Tibetan Plateau were Denisovans
Zhang Dongju (upper right in the ditch) led the excavation team
at the Baishi Cliff cave in 2018 [Credit: Zhang Dongju]

Attached to the mandible was a heavy carbonate crust. By applying U-series dating to the crust, the researchers found that the Xiahe mandible is at least 160,000 years old, representing a minimum age of human presence on the Tibetan Plateau.


The similarities between the Xiahe mandible and other Chinese specimens confirm the presence of Denisovans among the current Asian fossil record. The current study paves the way towards a better understanding of the evolutionary history of Middle Pleistocene hominins in East Asia.


Source: Chinese Academy of Sciences [May 07, 2019]



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Bronze Age burial unearthed in Orkney

A team from ORCA Archaeology has discovered a 3,500 year old burial cist last week while undertaking exploratory archaeological excavations on behalf of SSEN Transmission in Orkney.











Bronze Age burial unearthed in Orkney
Bronze Age Cist Discovered at the Proposed SSEN Finstown
Sub Station Site, Orkney [Credit: Orca]

The cist was found intact at the proposed Finstown substation site, just below the ground surface, and consists of a stone-lined box capped with a large flat stone, and would probably have contained the remains of an individual who lived during the Bronze Age.
The burial was discovered by ORCA Archaeology as part of SSEN Transmission’s commitment to undertake environmental survey works ahead of construction, should the substation be approved. Local soil conditions aren’t great for the preservation of bone, and at first sight the cist appears empty, but careful excavation may reveal some traces.


Standing around the cist in perhaps the same position as mourners did 3,500 years ago, the ORCA Archaeology team discussed with SSEN Transmission the importance of the find and the next steps involved in excavation and recording, and the implications of the discovery for our understanding of how people lived and worked in the landscape.



Pete Higgins, Senior Project Manager ORCA Archaeology said, “Previous survey work told us there was significant archaeology present at the site and we are pleased that within the first few days we have our first major find. It is fascinating to think that we are the first people in 3,500 years to look into this structure. We are working with SSEN Transmission to record the archaeology of the site, and this is a great start.”
SSEN Transmission has submitted a planning application for the onshore substation near Finstown. The substation is a critical component of the proposed network reinforcement which is required to support renewable electricity generators across Orkney looking to connect to the main GB transmission system for the first time.


Its progress, as well as that of the reinforcement programme, remains subject to all planning and regulatory approvals. SSEN Transmission’s Environmental Project Manager, Simon Hall continues, “As a responsible network operator, we take our environmental standards very seriously and strive to do everything we can to ensure that our proposed works minimise disruption and impact to our host communities, whilst meeting our License obligations. For this particular project, that includes working with local archaeological experts ORCA as part of our pre-construction assessments to fully understand the archaeological features and history at the Finstown site. We are delighted that it has resulted in the discovery of such an exciting feature that otherwise may never have been found. We look forward to continuing to work closely with ORCA as the excavation progresses.”


Source: ORCA [May 07, 2019]



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Cannibalism was profitable for Homo antecessor

Scientists at the Centro Nacional de Investigacion sobre la Evolucion Humana (CENIEH), have just published a study in the Journal of Human Evolution in which they analyze the cannibalistic behaviour of the populations at Atapuerca one million years ago, whose results make it clear that anthropophagy was a profitable strategy for Homo antecessor.











Cannibalism was profitable for Homo antecessor
Credit: J.Rodriguez

A very large number of studies have demonstrated that animals adapt their feeding strategies to optimize the cost-benefit balance, and starting with this principle, these CENIEH researchers have studied the cannibalistic behaviour of Homo antecessor, reexamining the data furnished by other earlier work.


Not only have they estimated the amount of food which could have been obtained from each of the animals consumed by Homo antecessor (the benefit) and the effort which obtaining and processing one of these animals would have entailed (the cost), but they have also calculated the cost and the benefit of consuming other humans when compared with data for other prey.


“Our analyses show that Homo antecessor, like any predator, selected its prey following the principle of optimizing the cost-benefit balance, and they also show that, considering only this balance, humans were a ‘high-ranked’ prey type. This means that, when compared with other prey, a lot of food could be obtained from humans at low cost”, explains Rodriguez.


One of the most surprising results of this study has been that humans were consumed in a much greater proportion than would be expected from their abundance relative to other animals. This might be explained by a high encounter rate between humans.


Indeed, as Mateos explains, “for Homo antecessor it was easier to encounter a human than another animal. One of the possible explanations for this high encounter rate between humans could be that the cannibalized cadavers were those of members of the group who had died from different causes”.


Source: CENIEH [May 07, 2019]



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Wheat, wine and wool: What old account statements reveal

Imagine archaeologists working 2,000 years from now to decipher the account statements of a large commercial enterprise that ended up in the bin in 2018 and have been forgotten since. The majority of these notes are in a deplorable condition: eaten by mice, glued together, torn and fragmentary, and written in a strange script that cannot be found in any other place.











Wheat, wine and wool: What old account statements reveal
To explore the Egyptian temple economy through a particular genre of sources: This is the aim of the DimeData
research project. The project is led by Professor Martin Andreas Stadler, holder of the Chair of Egyptology;
Dr. Maren Schentuleit, research assistant to the Chair, will be responsible for the concrete work
[Credit: Gunnar Bartsch/Universitat Wurzburg]

What makes the work even more difficult is that the individual scraps of paper are not neatly collected in one place, but are distributed across many museums and libraries in Europe. Which is why, for example, no one has yet noticed that the upper half of a rather unfortunate note is in Vienna, while the lower half is in Berlin.


€450,000 from France and Germany


We must confess: The comparison with today’s account statements isn’t quite correct. Nevertheless, it provides a good picture of the work that Egyptologists from the Julius-Maximilians-University of Wurzburg (JMU) and their colleagues from Bordeaux will be doing in the coming years. DimeData: This is the name of the research project that the French Agence nationale de la recherche (ANR) and the German Research Foundation (DFG) have now approved. The two institutions will provide around €450,000 over the next three years, a good half of which will go to the JMU. The project leader there is Professor Martin Andreas Stadler, holder of the Chair of Egyptology, and Lecturer Dr. Maren Schentuleit, research assistant to the Chair, will be responsible for the concrete work.


The aim of the project is to investigate the Egyptian temple economy from sources that are «rich in content, difficult, fragile at first glance, but then uniquely rich in detail», as Stadler says. At the same time, they will being publication of an online platform with the edition of around 40 representative texts. Under the keyword «Digital Humanities», ancient historians and Egyptologists will be provided with new sources that will put the knowledge about the economic life of Egyptian temples in the Roman Empire on a new footing. In fact, the researchers involved assume that the results of their investigations will force researchers to revise their understanding of the situation during this period.


Lists of accounts concerning economic management


«In this project we are concentrating on lists of accounts from the economic management of the temple of Dime, which originated around the time from 30 BCE to the second century CE», explains Stadler. At that time Rome had taken power in Egypt. While older research blamed the Romans for the decline of the temples in Egypt, today it is believed that Rome even provided economic stimulation in Egypt. This controversy is one of the motivations of the research project that has now been launched.


Southwest of Cairo, in the middle of the desert, near the oasis Fayum, lie the remains of the temple Dime. The temple was dedicated to Soknopaios, who was often depicted with a crocodile’s body and a falcon’s head. Around the middle of the third century BCE the place was abandoned and never populated again, which proved to be a stroke of luck. In the dry desert, ancient documents on papyrus remained well preserved until they were accidentally rediscovered at the end of the 19th century. Unfortunately, the text fragments were then sold without treatment by archaeologists and mixed with other finds; today they are scattered in museums and collections in Vienna and Berlin, London and Paris, as well as many other places.


Papyrus rolls several metres long


These papyri can be up to two and a half metres long. Narrowly described in long columns, the editions of the temple treasury are recorded over many years in such papyri. «There, for example, people are listed who were paid by the temple», explains Maren Schentuleit. These are priests or scribes on the one hand, but also state officials and inspectors on the other. From such sources, a good picture of the contacts between Egyptian temples and Roman administration can be gained.


Wheat, bread, olive oil, olives — salted or marinated in water: The temple’s expenses for everyday goods are also meticulously noted on the papyri and provide information about consumer habits in Egypt around 2,000 years ago. Ideally, they enable researchers to draw conclusions about price trends over centuries, and thus also about economic change during this period. Wool, beer, wine- the latter even in different qualities: The menu of antiquity hardly seems to differ from a modern one.


A writing that is difficult to decipher


Philology is not simply a matter of «read and translate», however, especially with the papyri from Dime, because those fragments are written in demotic writing. «This was a handwriting used especially for everyday use. It originally derived from hieroglyphic writing, and emerges around 650 BCE», says Stadler. The deciphering of this writing is a challenge even for experts, especially because the writers in Dime had also developed their own writing style. As if that weren’t enough difficulties, there is also the fact that many of the ancient documents are full of holes, torn, and fragmentary, with parts of one and the same fragment kept in different collections without anyone knowing.


«Anyone who specialises in demotic texts must enjoy deciphering, and be patient, persistent, and be able to tolerate frustration (at every turn),» says Maren Schentuleit. Translating an entire column in one day already counts as a great success, remarks the Egyptologist. Of course, after years of working with this script, she has a rich set of skills at her disposal to help her decipher it. In demotic writing, for example, there is always a descriptive element at the end of the word that indicates whether it is a plant, a mineral or a type of material — helping to narrow down the search for solutions.


The joy of repetition


When trying to decipher completely unknown words, Schentuleit looks for a connection with words in the older Egyptian or later Coptic language, hoping that similarities will help her. Or, she remembers having already seen the same combination of signs in another text and can draw conclusions about the meaning in a new context. For this reason, too, the Egyptologist can come to appreciate researching accounting lists — a text genre that otherwise promises little reading pleasure. «They contain many repetitive elements and thus enable comparisons to be made across many text fragments».


The aim is, within three years, to edit 40 texts and produce an online database. «We are doing important preliminary work for younger scholars and laying the foundation for further research projects», explains Stadler. And, of course, the results will help to significantly improve our understanding of temples as economic centres in Egypt, their relationships with other temples, intellectual exchange within the country — and, ideally, the controversy over the influence of the Romans on these Egyptian institutions.


Source: Julius-Maximilians-Universitat Wurzburg [May 07, 2019]



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Roman gaming board discovered at Vindolanda

After a day’s duty on the frontier of Hadrian’s Wall , what better than a relaxing game of Ludus latrunculorum. The game of strategy and military tactics was popular across the Roman empire, and a stone board on which it may have been played has been uncovered at Vindolanda fort in Northumberland .











Roman gaming board discovered at Vindolanda
The gaming board is unearthed at Vindolanda
[Credit: Newcastle Chronicle]

This third century board was found by volunteer digger Phil Harding re-used in a floor, in a newly excavated building behind the Vindolanda bath house. It is thought that the board would have been in use in the bath house and then utilised elsewhere after it was broken.


“You can almost picture the losing Roman tipping the board up in frustration, causing it to break,” said a Vindolanda spokesperson.


A total of five good examples of gaming boards have been found at Vindolanda over the years, and all date from the third and fourth centuries.


Ludus latrunculorum was a game for two players across a rectangular board marked with a grid of squares. The players each have an equal number of pieces, with one player’s differing from the other in colour. Pieces move around the board and capture one another. A piece of one colour caught between two of the other is removed from play. The winner is the player who captures all of the opponent’s pieces. Gaming pieces, which were made from pottery glass or stone, have also been found at the fort in the past.











Roman gaming board discovered at Vindolanda
The hipposandals on display at the Roman Army Museum
[Credit: Newcastle Chronicle]

Meanwhile, one of the top finds from last year’s excavation season at Vindolanda has now gone on display at the fort’s sister site of the Roman Army Museum at Carvoran on Hadrian’s Wall. The group of four hipposandals, found in two sets of two, had been discarded in a ditch dating to AD 140-180. Various theories have been put forward regarding the purpose of hipposandals, including:


Temporary horseshoes: The most common theory is that these iron objects were a type of horseshoe. They were not nailed to horses’ hooves like modern horseshoes but were worn tied with cords. Hipposandals could be fitted by anyone who owned a horse, with little need for specialist farrier knowledge. They could be carried easily, and just as easily be replaced and would have been useful when on remote postings or expeditions. Some researchers believe that hipposandals are not horseshoes but could only have been used on slower pack animals such as oxen, mules and donkeys.


Hobbles (leg restraints): The hipposandals could have been fitted on two or four hooves. The front hooves would have been fitted with hipposandals equipped with front-facing loops, that would have then been tied together. This would have only allowed the horse to move a few inches at a time and would have stopped pasturing horses from straying.


Medicinal, offensive or traction horseshoes: Hipposandals could have been used as a medicinal shoe, which could carry a salve packed in or around the iron and therefore kept firmly on the hoof and frog (the soft part of a hoof located on the underneath of the foot). They could have also been used for offensive purposes, for example, riding into battle wearing these would have avoided painful caltrops devices scattered to make a horse lame, or for better traction on ice and mud.


The Vindolanda Trust is also appealing for public help in funding a new development at the fort, which will be used as a base for volunteer excavators and for the first stage of processing finds. The Robin Birley Archaeology Centre will be named after the late founding director of the Vindolanda Trust, who for more than 30 years ran the fort site and nearby Roman Army Museum.


The design of the centre links back to the former Nissen huts which were used for education purposes at the fort in the 1970s, as well as the vaulted roof structure of the Roman bath house which is adjacent to the site. The Vindolanda Trust has appointed Newcastle-based Napper Architects to design the new facility, which incorporates rainwater recycling. It is hoped to start construction in October.


The funding target for the new project is £100,000. To help, go to www.vindolanda.com/appeal/vindolanda-archaeology-centre


Author: Tony Henderson | Source: Vhronicle Live [May 07, 2019]



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Why This Martian Full Moon Looks Like Candy


NASA —  2001 Mars Odyssey Mission patch.


May 9, 2019



Image above: These three views of the Martian moon Phobos were taken by NASA’s 2001 Mars Odyssey orbiter using its infrared camera, THEMIS. Each color represents a different temperature range. Image Credits: NASA/JPL-Caltech/ASU/SSI.


For the first time, NASA’s Mars Odyssey orbiter has caught the Martian moon Phobos during a full moon phase. Each color in this new image represents a temperature range detected by Odyssey’s infrared camera, which has been studying the Martian moon since September of 2017. Looking like a rainbow-colored jawbreaker, these latest observations could help scientists understand what materials make up Phobos, the larger of Mars’ two moons.


Odyssey is NASA’s longest-lived Mars mission. Its heat-vision camera, the Thermal Emission Imaging System (THEMIS), can detect changes in surface temperature as Phobos circles Mars every seven hours. Different textures and minerals determine how much heat THEMIS detects.



Animation above: This movie shows three views of the Martian moon Phobos as viewed in visible light by NASA’s 2001 Mars Odyssey orbiter. The apparent motion is due to movement by Odyssey’s infrared camera, Thermal Emission Imaging System (THEMIS), rather than movement by the moon. Animation Credits: NASA/JPL-Caltech/ASU/SSI.


«This new image is a kind of temperature bullseye — warmest in the middle and gradually cooler moving out,» said Jeffrey Plaut, Odyssey project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, which leads the mission. «Each Phobos observation is done from a slightly different angle or time of day, providing a new kind of data.»


On April 24, 2019, THEMIS looked at Phobos dead-on, with the Sun behind the spacecraft. This full moon view is better for studying material composition, whereas half-moon views are better for looking at surface textures.


«With the half-moon views, we could see how rough or smooth the surface is and how it’s layered,» said Joshua Bandfield, a THEMIS co-investigator and senior research scientist at the Space Sciences Institute in Boulder, Colorado. «Now we’re gathering data on what minerals are in it, including metals.»


Iron and nickel are two such metals. Depending on how abundant the metals are, and how they’re mixed with other minerals, these data could help determine whether Phobos is a captured asteroid or a pile of Mars fragments, blasted into space by a giant impact long ago.


These recent observations won’t definitively explain Phobos’ origin, Bandfield added. But Odyssey is collecting vital data on a moon scientists still know little about — one that future missions might want to visit. Human exploration of Phobos has been discussed in the space community as a distant, future possibility, and a Japanese sample-return mission to the moon is scheduled for launch in the 2020s.



Image above: Artist’s concept of NASA’s Mars Odyssey spacecraft. Image Credit: NASA/JPL.


«By studying the surface features, we’re learning where the rockiest spots on Phobos are and where the fine, fluffy dust is,» Bandfield said. «Identifying landing hazards and understanding the space environment could help future missions to land on the surface.»


Odyssey has been orbiting Mars since 2001. It takes thousands of images of the Martian surface each month, many of which help scientists select landing sites for future missions. The spacecraft also serves an important role relaying data for Mars’ newest inhabitant, NASA’s InSight lander. But studying Phobos is a new chapter for the orbiter.


«I think it’s a great example of taking a spacecraft that’s been around a very long time and finding new things you can do with it,» Bandfield said. «It’s great that you can still use this tool to collect groundbreaking science.»


NASA’s Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA’s Science Mission Directorate in Washington. THEMIS was developed by Arizona State University in Tempe in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Philip Christensen at Arizona State University. The prime contractor for the Odyssey project, Lockheed Martin Space in Denver, developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of Caltech in Pasadena.


— Thermal Emission Imaging System (THEMIS): https://themis.asu.edu/


— Mars Odyssey: http://www.nasa.gov/mission_pages/odyssey/


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


Greetings, Orbiter.chArchive link


Tsunami signals to measure glacier calving in Greenland…


Tsunami signals to measure glacier calving in Greenland http://www.geologypage.com/2019/05/tsunami-signals-to-measure-glacier-calving-in-greenland.html


Radioactive carbon from nuclear bomb tests found in deep ocean…


Radioactive carbon from nuclear bomb tests found in deep ocean trenches http://www.geologypage.com/2019/05/radioactive-carbon-from-nuclear-bomb-tests-found-in-deep-ocean-trenches.html


Complex geology contributed to Deepwater Horizon disaster, new…


Complex geology contributed to Deepwater Horizon disaster, new study finds http://www.geologypage.com/2019/05/complex-geology-contributed-to-deepwater-horizon-disaster-new-study-finds.html


Zebra Schist : What is Zebra Schist? Where is it found?…


Zebra Schist : What is Zebra Schist? Where is it found? http://www.geologypage.com/2019/05/zebra-schist-what-is-zebra-schist-where-is-it-found.html


More cracks found in 1000-year-old Viking ship

Officials at Oslo’s famed Viking Ship Museum have found more cracks in the wooden Gokstad ship that’s been on public display since 1932. Anxious experts have added to its support apparatus, in the hopes of preventing the ancient vessel from collapsing.











More cracks found in 1000-year-old Viking ship
The Gokstad ship at The Viking Ship Museum
[Credit: Museum of Cultural History]

“When 1,000-year-old ship planks begin to weaken, the situation is extremely serious,” said Hakon Glorstad, director of the University of Oslo’s Museum of Cultural History that’s responsible for the Viking ships. “Wood that’s so old doesn’t have the same flexibility as modern wood and can totally collapse, quickly and without warnng.”


More cracks found in 1000-year-old Viking ship










More cracks found in 1000-year-old Viking ship
Crack in the hull of the Gokstad ship [Credit: Dan P. Neegaard]

Glorstad told newspaper Aftenposten on Monday that in its current location, “we can’t develop the overall support systems needed to secure the ship’s entire hull.” He said the current base is no longer adequate and the space around the ship too confined.











More cracks found in 1000-year-old Viking ship
Carefully placed supports with sensors mitigate and monitor the cracking
[Credit: Dan P. Neegaard]










More cracks found in 1000-year-old Viking ship
The University of Oslo’s David Hauer monitors Gokstad ship movement
[Credit: Dan P. Neegaard]

The museum has been sounding alarms for months, even years, about the condition of the vessels and has been promised new surroundings for its three Viking ships found in Vestfold between 1857 and 1904. The government has granted project funding but not funding for the actual construction of an expanded Viking ship museum at its current location at Bygdoy, meaning no new facility to better preserve the ships will be finished before 2025 at the earliest.


Source: newsinenglish.no [May 07, 2019]



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