суббота, 3 августа 2019 г.

Azurite | #Geology #GeologyPage #Mineral Locality: Kamariza…


Azurite | #Geology #GeologyPage #Mineral


Locality: Kamariza Mines, Agios Konstantinos, Lavrion District Mines, Attiki Prefecture, Greece, Europe


Dimensions: 11.0 × 5.4 × 5.0 cm


Photo Copyright © Crystal Classics


Geology Page

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Dyke cutting Canary Islands, Spain | #Geology #GeologyPage #Dyke…


Dyke cutting Canary Islands, Spain | #Geology #GeologyPage #Dyke #Spain


The dyke morphology is diverse, ranging from massive to intensely fractured or crushed, from highly vesicular to low vesicularity and from straight to bendy. Orientations of individual dykes are usually constant at the outcrop scale, but local changes in strike, in dip or both have sometimes been observed.


More Info & More Photos: http://www.geologypage.com/2019/03/dyke-cutting-canary-islands-spain.html


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Fun in the Sun Fun in the sun always comes with warnings –…


Fun in the Sun


Fun in the sun always comes with warnings – always apply a good sunscreen, with a cocktail of protective chemicals that block some of the sun’s UV light. Over-exposure might otherwise damage skin cells, and perhaps their DNA too, leading to cancers like melanoma. One detail that’s perhaps forgotten is how often to “cream up” – as its protective effect only lasts for a few hours. Spectators at a recent cricket test match in Australia were asked to trial a new skin-saving sticker, which changes colour to remind the wearer to re-apply. Worn of the hand here, ‘SPOTMYUV’ stickers change from colourless to purple as chemicals inside react to the sunlight. One side of these stickers are lathered with a sun cream, showing how its protection eventually wears off. These discreet devices could be just the thing to reduce the cases of melanomas, and sunburn, worldwide.


Written by John Ankers



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Space Station Science Highlights: Week of July 29, 2019


ISS — Expedition 60 Mission patch.


Aug. 2, 2019


The recent arrival of the 18th SpaceX Commercial Resupply Services (CRS-18) mission brought with it a number of new scientific investigations. Astronauts aboard the International Space Station kicked off some of these new experiments this week while continuing existing investigations. This research included studies of motion control in space, printing of biological tissue and robot swarms. The orbiting laboratory provides a platform for commercial research that supports Artemis, NASA’s program to return humans to the Moon as a stepping stone to Mars.



Image above: The Dragon capsule on the 18th SpaceX Commercial Resupply services mission docks with the International Space Station. Image Credit: NASA.


Here are details on some of the science conducted on the space station during the week of July 29:


New experiments hot off the Dragon


Last week saw the start of new experiments that arrived aboard the Dragon capsule on Saturday, July 27. Crew members installed the BioFabrication Facility, which provides a platform to attempt printing biological tissues in microgravity. This investigation could serve as a first step toward achieving the ability to fabricate entire human organs in space. The astronauts also began and documented the BioRock experiment, which is testing space-based biomining, the process of using microbes to extract minerals from rocks.


Get a GRIP



Animation above: NASA Astronaut Andrew Morgan perfects a seated session of the GRIP experiment, which analyzes motion control in space. Animation Credit: NASA.


The crew collected data to study how being in the microgravity environment affects the nervous system and movement control as part of the European Space Agency’s GRIP experiment. Researchers are testing the ability of astronauts to manipulate items and control their arm motions in space by following a system of beeps and lights that indicate how they should move their arms and hands. Researchers will analyze this data and see how motion control in space differs from on the ground. These results could help scientists understand how gravity affects movement on Earth and may benefit patients with neurological diseases.


Prepping for student-controlled robots on the space station


With advances in propulsion, swarms of small spacecraft are expected to become feasible in the near future, creating a new range of capabilities for Earth and space observation missions. The SPHERES robots are putting some of these technologies to the test. Last week, the crew prepared to run code from participants of the SPHERES Zero Robotics (ZR) 2019 Middle School Summer Program. The SPHERES team tests algorithms developed by students and selects the best designs for the competition to operate the robots on board the space station.


Building stronger bones



Animation above: NASA astronaut Nick Hague handles the Cell Science-02 experiment. Animation Credit: NASA.


The Cell Science-02 investigation examines how microgravity affects healing, tissue regeneration and agents that induce healing. Astronauts used the Life Sciences Glovebox to conduct research into bone regeneration, retrieving bone cell samples to observe healing and tissue regeneration properties. The investigation has potential applications for treating those dealing with impaired healing of serious wounds and bone loss due to osteoporosis on Earth. It also could assist in developing better countermeasures against loss of bone density by astronauts in space.


Other investigations on which the crew performed work:


— ACME Flame Design, which studies the production and control of soot to optimize oxygen-enriched combustion and the design of robust, soot-free flames, is part of a series of independent ACME experiments using the orbiting laboratory’s Combustion Integrated Rack (CIR):
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1651


https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317


— The ISS Experience creates short virtual reality videos from footage taken during the yearlong investigation covering different aspects of crew life, execution of science and the international partnerships involved on the space station:
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7877


— The Actiwatch is a wristwatch-like monitor containing an accelerometer to measure motion and color-sensitive photodetectors for monitoring ambient lighting to help analyze the crew’s circadian rhythms, sleep-wake patterns and activity:
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=838


— Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions. “Menu fatigue” from repeatedly consuming a limited choice of foods may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases:
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562


— Rodent Research-17 (RR-17) uses young and old mice to evaluate the physiological, cellular and molecular effects of microgravity and spaceflight:
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7992


— Space Moss determines how microgravity affects the growth, development and other features of moss. Tiny plants without roots, mosses need only a small area for growth, an advantage for their potential use in space and future bases on the Moon or Mars:
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7892



Space to Ground: Fast Track: 08/02/2019

Related links:


Expedition 60: https://www.nasa.gov/mission_pages/station/expeditions/expedition60/index.html


Artemis: https://www.nasa.gov/feature/what-is-artemis/


BioFabrication Facility: https://www.youtube.com/watch?v=s9csx38k8Zo


BioRock experiment: https://www.nasa.gov/mission_pages/station/research/news/biorock-iss-research-microbes-space


GRIP experiment: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1188


SPHERES: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7753


SPHERES Zero Robotics (ZR): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=679


Cell Science-02: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1676


Life Sciences Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7676


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


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


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


Image (mentioned), Animations (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/Vic Cooley, Lead Increment Scientist Expedition 60.


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Study suggests frozen earthlike planets could support life

Icy planets once thought too cold to support life might have livable land areas above freezing, challenging the typical assumption of what kinds of planets might be habitable, a new study suggests.











Study suggests frozen earthlike planets could support life
An artist’s rendition of what a snowball planet might look like. Ice covers the oceans
to the equators [Credit: NASA]

Scientists have long thought snowball planets—Earthlike planets with oceans frozen to the equator—were hostile to life because of the extreme cold. But new research in AGU’s Journal of Geophysical Research: Planets finds some snowball planets might have areas of land near their equators that reach livable temperatures.


«You have these planets that traditionally you might consider not habitable and this suggests that maybe they can be,» said Adiv Paradise, an astronomer and physicist at the University of Toronto and lead author of the new study.


The habitable zone is a range of distances from a star where a planet could theoretically have liquid water and temperatures warm enough to support life. Planets in the habitable zone can be warm and temperate like Earth, or entirely frozen, like snowball planets.


Geologists suspect Earth has gone through anywhere from one to three snowball phases in the past and that marine microorganisms likely survived through at least one of those periods.


«We know that Earth was habitable through its own snowball episodes, because life emerged before our snowball episodes and life remained long past it,» Paradise said. «But all of our life was in our oceans at that time. There’s nothing about the land.»


In the new study, Paradise and his colleagues wanted to know if areas of land on snowball planets could reach life-sustaining temperatures. They used a computer program to simulate different climate variables on theoretical snowball planets, adjusting conditions like the amount of sunlight and configuration of the continents.


One variable they were interested in was carbon dioxide. Carbon dioxide traps heat and keeps a planet in a temperate climate range; without it, planets cool and oceans freeze.











Study suggests frozen earthlike planets could support life
This graph shows the relationship between carbon dioxide produced by volcanic activity and carbon dioxide
 removed from rainfall and erosion for temperate and snowball climates. Planets become stuck in a
snowball state when volcanic activity and weathering rates balance each other out
[Credit: AGU]

Planets become snowballs when their atmospheric carbon dioxide levels drop too low from a combination of rainfall and erosion. Water absorbs carbon dioxide and turns it into carbonic acid, which reacts with rocks on the ground during erosion. This interaction breaks carbonic acid down more. It binds with minerals, which are then carried to the oceans and eventually stored into the seafloor.


Scientists previously thought carbon dioxide removal from a planet’s atmosphere stopped during snowball phases because all of its surface water was frozen. But surprisingly, the new study found some snowball planets continue to lose carbon dioxide even after they’ve frozen. This means the planets would have to have some non-frozen ground and occasional rainfall for water to continue to remove carbon dioxide from the atmosphere.


Some of the warmer snowball planets the study’s authors simulated had land areas warm enough to hold liquid water and life even when their oceans were frozen to their equators. They found land areas in the center of the continents away from the frozen oceans could reach temperatures above 10 degrees Celsius (50 degrees Fahrenheit). This is much warmer than the lowest temperature at which life can reproduce, which scientists estimate to be minus 20 degrees Celsius (minus 4 degrees Fahrenheit).


The results also suggest Earthlike planets can become stuck in a snowball state under certain conditions. Scientists used to think planets exited snowball phases through a gradual buildup of carbon dioxide released by volcanoes. But weathering could draw out enough carbon dioxide out of the atmosphere to balance volcanic output, creating a negative feedback loop where the planet never thaws, according to the researchers.


The findings suggest the boundary between what is a habitable planet and what is not may not be as definite as geologists once thought, according to the researchers.


«What we find is actually that line is a bit fuzzy,» Paradise said.


Author: Abigail Eisenstadt | Source: American Geophysical Union [July 30, 2019]



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Flowing Antarctic ice mapped 10 times more accurately

Constructed from a quarter century’s worth of satellite data, a new map of Antarctic ice velocity by glaciologists from the University of California, Irvine and NASA’s Jet Propulsion Laboratory is the most precise ever created.











Flowing Antarctic ice mapped 10 times more accurately
The new map’s «more detailed representation will help improve our understanding of ice behavior under climate stress
over a larger part of the continent, farther south, and will enable improved projections of sea level rise through
numerical models,» says Jeremie Mouginot, UCI associate researcher in Earth system science
and the study’s lead author [Credit: Jeremie Mouginot/UCI]

Published in a paper in the American Geophysical Union journal Geophysical Research Letters, the map is 10 times more accurate than previous renditions, covering more than 80 percent of the continent.


«By utilizing the full potential of interferometric phase signals from satellite synthetic-aperture radars, we have achieved a quantum leap in the description of ice flow in Antarctica,» said lead author Jeremie Mouginot, UCI associate researcher in Earth system science. «This more detailed representation will help improve our understanding of ice behavior under climate stress over a larger part of the continent, farther south, and will enable improved projections of sea level rise through numerical models.»


To chart the movement of ice sheets across the surface of the enormous land mass, the researchers combined input from six satellite missions: the Canadian Space Agency’s Radarsat-1 and Radarsat-2; the European Space Agency’s Earth remote sensing satellites 1 and 2 and Envisat ASAR; and the Japan Aerospace Exploration Agency’s ALOS PALSAR-1.


While the data were spread across 25 years, the pace of signal gathering accelerated in the last decade as more resources were deployed in the Earth’s orbit. As ice sheet science coordinator in the World Meteorological Organization’s Polar Space Task Group, co-author Bernd Scheuchl, UCI associate project scientist in Earth system science, was responsible for acquiring the relevant data from the various international space agencies.


Previous mapping efforts relied heavily on «feature» and «speckle tracking» methods, which detect the subtle motion of parcels of ice on the ground over time; this approach has been proven effective in estimating ice flow speed. To measure significantly slower ice sheet movement in the vast interior regions, the UCI team augmented these techniques with synthetic-aperture radar phase interferometry, which detects the subtle motion of natural reflectors of radar signals in snow/ice independent of the size of the parcel of ice illuminated by the radar.


«The interferometric phase of SAR data measures the ice deformation signal with a precision of up to two orders of magnitude better than speckle tracking,» Mouginot said. «A drawback is that it requires a lot more data, namely multiple passes at different angles over the same point on the ground—a problem that was solved by a consortium of international space agencies pointing Earth-monitoring spacecrafts to this part of the world.»


The team was able to compose a map that resolves ice movement to a level of 20 centimeters (a little over half a foot) per year in speed and 5 degrees in annual flow direction for more than 70 percent of Antarctica. It’s the first time that high-precision mapping of the interior areas has been accomplished.


«This product will help climate scientists achieve a number of goals, such as a better determination of the boundaries between glaciers and a thorough evaluation of regional atmospheric climate models over the entire continent,» said co-author Eric Rignot, chair and Donald Bren Professor of Earth System Science at UCI and a JPL senior research scientist.


«It will also help in locating the most promising sites for ice core drilling to extract climate records and in examining the mass balance of Antarctica beyond its periphery.»


He said he’s looking forward to the joint NASA and Indian Space Research Organization satellite, launching in late 2021, which will be the first interferometric-mode SAR mission designed to look solely toward the South Pole. The spacecraft will provide a coast-to-coast view of Antarctica every 12 days.


«We’ll be able to collect enough quality phase data over the Antarctic to generate updates to the map we just created in one or two months instead of one or two decades,» Rignot said. «With this level of precision in the interior regions, we’ll be able to reconstruct high-resolution spatial details in the bed topography beneath the ice through inversion techniques over far broader areas than in previous attempts—essential to improving ice sheet models and projections of sea level rise from Antarctica.»


Source: University of California, Irvine [July 30, 2019]



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Introduced species dilute the effects of evolution on diversity

Understanding how biodiversity is shaped by multiple forces is crucial to protect rare species and unique ecosystems. Now an international research team led by the University of Gottingen, German Centre for Integrative Biodiversity Research (iDiv) and the Helmholtz Centre for Environmental Research (UFZ), together with the University of Hawai’i at Manoa, has found that biodiversity is higher on older islands than on younger ones. Furthermore, they found that introduced species are diluting the effects of island age on patterns of local biodiversity. The findings were published in Proceedings of the National Academy of Sciences.











Introduced species dilute the effects of evolution on diversity
Ko’olau Mountain range on Oahu — the third largest of the Hawaiian Islands. Researchers investigated
the effects on biodiversity of introduced species and island age [Credit: William Weaver]

Oceanic islands, such as the Hawaiian archipelago, have long been a natural laboratory for scientists to analyse evolutionary and ecological processes. In such archipelagos, islands formed by undersea volca-noes often differ in age by several millions of years, allowing scientists to look at the long-term impacts of geology and evolution on biodiversity.
In this study, researchers used data from more than 500 forest plots across the archipelago to explore how historical and recent ecological processes influence the number of species that coexist — whether at the scale of an island or a much smaller area such as a typical backyard. Their analysis showed that even within small plots, older islands had a greater number of both rare species as well as native species when compared with islands formed more recently.











Introduced species dilute the effects of evolution on diversity
The Ko’olau summit on the island of O’ahu in Hawai’i where researchers found that biodiversity is higher in forests
on older islands than on younger ones, but that this effect may be diluted by introduced species
[Credit: William Weaver]

The researchers were able to compare data from older islands such as Kau’I (which is around 5 million years old) with islands like the Big Island of Hawai’i (which is only around 500,000 years old and still growing). «To be honest, I was a bit sur-prised by the results. I expected that ecological mechanisms would outweigh the macroevolutionary forces at the scales of these small plots, and that there’d be no differences in local-scale diversity among the is-lands,» says Jonathan Chase (iDiv and Martin Luther University Halle-Wittenberg), senior author of this study. «So, to me, this is the coolest kind of discovery—one that challenges your assumptions».


They also showed that widespread introduced species weakened the effect of island age on biodiversity, by making Hawaiian forests more similar to one another. Dylan Craven from the University of Gottingen and lead author of the study, says, «We’re seeing evidence that human activity — such as planting introduced species in our gardens and parks — is starting to erase millions of years of history, of plants and animals interacting with one another and their environment.»


Source: University of Gottingen [July 30, 2019]



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2019 August 3 Mimas in Saturnlight Image Credit: Cassini…


2019 August 3


Mimas in Saturnlight
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA


Explanation: Peering from the shadows, the Saturn-facing hemisphere of Mimas lies in near darkness alongside a dramatic sunlit crescent. The mosaic was captured near the Cassini spacecraft’s final close approach on January 30, 2017. Cassini’s camera was pointed in a nearly sunward direction only 45,000 kilometers from Mimas. The result is one of the highest resolution views of the icy, crater-pocked, 400 kilometer diameter moon. An enhanced version better reveals the Saturn-facing hemisphere of the synchronously rotating moon lit by sunlight reflected from Saturn itself. To see it, slide your cursor over the image (or follow this link). Other Cassini images of Mimas include the small moon’s large and ominous Herschel Crater.


∞ Source: apod.nasa.gov/apod/ap190803.html


Rising ocean temperatures killing Guam coral reefs

University of Guam researchers said increased temperatures killed 34% of Guam’s coral reefs between 2013 and 2017, The Pacific Daily News reported Monday. About 60% of the reefs along Guam’s eastern coast are gone, scientists said.











Rising ocean temperatures killing Guam coral reefs
Bleached coral in Guam [Credit: AP]

«Never in our history of looking at reefs have we seen something this severe,» said Laurie Raymundo, UOG marine lab director and marine biology professor.


The problem is too urgent to ignore because corals are vital to fish habitats, provide coastal protection and contribute to Guam’s tourism industry, Raymundo said.


A multi-agency Guam Coral Reef Response team monitors the island’s reefs and tries to revive coral communities in line with a 2017 recovery plan. Guam is now in watch status for another mass bleaching event, which precedes large-scale reef death.


«Once we see temperatures starting to rise, this is when we activate our plan,» said Whitney Hoot, Guam Bureau of Statistics and Plans coral reef resilience coordinator.


Negative effects could be reduced by making changes in local stressors such as Guam’s pollution, sewage system and plastic waste, researchers said. But elevated global carbon dioxide output is to blame for heightened water temperatures.


«It’s what we’re pumping into the atmosphere that is creating warmer temperatures,» Raymundo said, adding that places with «enormous populations» are contributing the majority of carbon entering the environment. «And it’s not small islands like Guam, nonetheless, we are affected by it.»


Guam is a territory of the United States in the western Pacific Ocean, about 5,800 miles (9,300 kilometers) west of San Francisco.


The study was published in the scientific journal Coral Reefs.


Source: The Associated Press [July 30, 2019]



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Siberia forest fires spark potential ‘disaster’ for Arctic

Gigantic forest fires have regularly raged through the vast expanses of Russia’s Siberia, but the magnitude of this year’s blazes has reached an exceptional level with fears of a long-term impact on the environment.











Siberia forest fires spark potential 'disaster' for Arctic
Battling wildfires in the Vilyuisky district [Credit: Svetlana Pavlova/TASS]

As fires sweep across millions of hectares enveloping entire cities in black smoke and noxious fumes, environmentalists warn of a disaster threatening to accelerate the melting of the Arctic.


More than 3.2 million hectares (7.9 million acres) were in the grip of fires on Monday, mainly in the vast regions of Yakutia in the north and Krasnoyarsk and Irkutsk in Siberia, authorities said.


The fires, triggered by dry thunderstorms in temperatures above 30 degrees Celsius (86 degrees Fahrenheit), were spread by strong winds, Russia’s federal forestry agency said.


The acrid smoke has affected not only small settlements but also major cities in Western Siberia and the Altai region as well as the Urals such as Chelyabinsk and Yekaterinburg, and disrupted air travel.


«The smoke is horrible. I am choking and dizzy,» pensioner Raisa Brovkina, who was hospitalised in Russia’s third-largest city Novosibirsk, told state television.


On Sunday, the smoke reached neighbouring Kazakhstan.


A «concentration of pollutants exceeding the norm» was recorded in several cities, including the capital Nur-Sultan, said the Kazakh meteorological service.


‘Ecological disaster’


Aside from health fears for the local population, environmentalists warn the fires may accelerate global warming.


«The forest fires in the eastern part of the country have long stopped being a local problem,» the Russian branch of Greenpeace said in a statement. «It has transformed into an ecological disaster with consequences for the entire country.»


According to the environmental group, almost 12 million hectares were burnt this year, causing significant CO2 emissions and reducing the future capacity of forest to absorb the carbon dioxide.











Siberia forest fires spark potential 'disaster' for Arctic
Map of Russia, highlighting Yakutia, Krasnoyarsk and Irkutsk regions where more than 3.2 million hectares
of forest went up in flames on Monday [Credit: AFP]

«Then there is the added problem that soot falling on ice or snow melts darkens it, thus reducing the reflectiveness of the surface and trapping more heat,» the World Meteorological Organization told AFP in a statement.


Some scientists posted satellite images from NASA showing the clouds of smoke reaching Arctic areas.


Greenpeace Russia expert Grigory Kuksin said the soot and ashes accelerate the melting of the Arctic ice and permafrost—the permanently frozen layer that has begun melting—releasing gases that reinforce global warming.


Kuksin called the impact on the climate «very serious.»


«It is comparable to the emissions of major cities,» he said. «The more fires affect the climate, the more conditions are created for new dangerous fires.»


Greenpeace has launched a petition demanding Russian authorities do more to fight the fires.


No resources to fight fires


But the situation is complicated by the fact that Russia does not have enough money to contain the wildfires, environmentalists add.


The majority of the fires rage in remote or inaccessible areas and authorities make the decision to extinguish them only if the estimated damage exceeds the cost of the operation, experts say.


Otherwise, the role of Russian authorities is limited to monitoring the wildfires, they say.


Kuksin of Greenpeace said Russian officials do not prioritise financial resources to put out fires in remote areas, taking issue with such an approach.


«The maximum amount possible should be put out from the start,» he said.


«We need to plan and allocate resources, but we continue to save money claiming it is ‘economically impractical’.»


Author: Maria Panina | Source: AFP [July 30, 2019]



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Origin of life: The importance of interfaces

Tiny gas-filled bubbles in the porous rock found around hot springs are thought to have played an important role in the origin of life. Temperature differences at the interface between liquid phases could therefore have initiated prebiotic chemical evolution.











Origin of life: The importance of interfaces
Credit: PerfectFitSolutions/Pixabay

A plethora of physicochemical processes must have created the conditions that enabled living systems to emerge on the early Earth. In other words, the era of biological evolution must have been preceded by a — presumably protracted — phase of ‘prebiotic’ chemical evolution, during which the first informational molecules capable of replicating themselves were assembled and selected. This scenario immediately raises another question: Under what environmental conditions could prebiotic evolution have taken place? One possible setting has long been discussed and explored — tiny pores in volcanic rocks. An international team of researchers led by Dieter Braun (Professor of Systems Biophysics at Ludwig-Maximilians-Universitaet (LMU) in Munich) has now taken a closer look at the water-air interfaces in these pores. They form spontaneously at gas-filled bubbles and show an interesting combination of effects.
They found that they could have played an important part in facilitating the physicochemical interactions that contributed to the origin of life. Specifically, Braun and his colleagues asked whether such interfaces could have stimulated the kinds of chemical reactions that triggered the initial stages of prebiotic chemical evolution. Their findings appear in the leading journal Nature Chemistry.


The study strongly supports the notion that tiny gas-filled bubbles that were trapped in, and reacted with, the surfaces of pores in volcanic rocks could indeed have accelerated the formation of the chemical networks that ultimately gave rise to the first cells. Thus, the authors were able to experimentally verify and characterize the facilitating effects of air-water interfaces on the relevant chemical reactions. If there is a difference in temperature along the surface of such a bubble, water will tend to evaporate on the warmer side and condense on the cooler side, just as a raindrop that lands on a window runs down the flat surface of the glass and eventually evaporates.


«In principle, this process can be repeated ad infinitum, since the water continuously cycles between the gaseous and the liquid phase,» says Braun, who has characterized the mechanism and the underlying physical processes in detail, together with his doctoral student Matthias Morasch and other members of his research group. The upshot of this cyclical phenomenon is that molecules accumulate to very high concentrations on the warmer side of the bubble.


«We began by making a series of measurements of reaction rates under various conditions, in order to characterize the nature of the underlying mechanism,» says Morasch. The phenomenon turned out to be surprisingly effect and robust. Even small molecules could be concentrated to high levels. «We then tested a whole range of physical and chemical processes, which must have played a central role in the origin of life — and all of them were markedly accelerated or made possible at all under the conditions prevailing at the air-water interface.» The study benefitted from interactions between Braun’s group of biophysicists and the specialists in disciplines such as chemistry and geology who work together with him in the Collaborative Research Centre (SFB/TRR) on the Origin of Life (which is funded by the DFG), and from cooperations with members of international teams.


For example, the LMU researchers show that physicochemical processes which promote the formation of polymers are either stimulated — or made possible in the first place — by the availability of an interface between the aqueous environment and the gas phase, which markedly enhances rates of chemical reactions and catalytic mechanisms. In fact, in such experiments, molecules could be accumulated to high concentrations within lipid membranes when the researchers added the appropriate chemical constituents. «The vesicles produced in this way are not perfect. But the finding nevertheless suggests how the first rudimentary protocells and their outer membranes might have been formed,» says Morasch.


Whether or not this sort of process can take place in such vesicles «does not depend on the nature of the gas within the bubble. What is important is that, owing to differences in temperature, the water can evaporate in one location and condense in another,» Braun explains. In earlier work, his group has already described a different mechanism by which temperature differences in water bodies can serve to concentrate molecules. «Our explanatory model enables both effects to be combined, which would enhance the concentrating effect and thus increase the efficiency of prebiotic processes,» he adds.


Source: Ludwig-Maximilians-Universitat Munchen [July 30, 2019]



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Researchers build artificial cells that sense and respond to their environment

Imperial College London scientists have created artificial cells that mimic biological cells by responding to a chemical change in their surroundings.











Calcium enters the artificial cells through a pore, which activates enzymes that cause the vesicles to release
 fluorescent particles through a protein channel [Credit: Zehua Hu/Imperial College London]

The artificial cells could be used to sense changes in the body and respond by releasing drug molecules, or to sense and remove harmful metals in the environment.


Responding to chemical changes is a crucial function of biological cells. For example, cells can respond to chemicals by creating certain proteins, boosting energy production, or self-destructing. Chemicals are also used by cells to communicate with each other and coordinate a response or send a signal, such as a pain impulse.


However, in natural cells these chemical responses can be very complex, involving multiple steps. This makes them difficult to engineer, for example if researchers wanted to make natural cells produce something useful, like a drug molecule.


Instead, the Imperial researchers are creating artificial cells that mimic these chemical responses in a much simpler way, allowing them to be more easily engineered.


Now, the team have created the first artificial cells that can sense and respond to an external chemical signal through activation of an artificial signalling pathway. They created cells that sense calcium ions and respond by fluorescing (glowing). Their results are published in Proceedings of the National Academy of Sciences.


First author James Hindley, from the Department of Chemistry at Imperial, said: «These systems could be developed for use across biotechnology. For example, we could envisage creating artificial cells that can sense cancer markers and synthesise a drug within the body, or artificial cells that can sense dangerous heavy metals in the environment and release selective sponges to clean them up.»


Activated by calcium, an enzyme alters the membrane of a vesicle, causing it to release fluorescent particles 


through the protein channel [Credit: Imperial College London]


The team created an artificial cell that has smaller cells (‘vesicles’) inside. The edge of the cell is formed of a membrane that contains pores, which allow calcium ions to enter. Inside the cell, the calcium ions activate enzymes that cause the vesicles to release particles that fluoresce.


James added: «Biology has evolved to be robust by using complex metabolic and regulatory networks. This can make editing cells difficult, as many existing chemical response pathways are extremely complicated to copy or engineer.


«Instead, we created a truncated version of a pathway found in nature, using artificial cells and elements from different natural systems to make a shorter, more efficient pathway that produces the same results.»


The researchers’ system is simpler because it doesn’t need to account for many of the things cells need to get around in natural systems — such as by-products that are toxic to the cell.


Within the system, the membrane pores and the enzymes activated by calcium are from existing biological systems — the enzyme is taken from bee venom for example — but they would not be found in the same environment in nature.


The researchers say this is the strength of using artificial cells to create chemical responses — they can more easily mix elements found apart in nature than they can add an external element into an existing biological system.


Advances from chemistry and nanotechnology can also be integrated, creating systems and pathways difficult to engineer in biology.


Co-author Professor Oscar Ces, from the Department of Chemistry at Imperial, said: «The plug-and-play aspect of our system means researchers can take elements from across nature to create new chemical pathways designed with specific aims in mind.


«Our template system is also easy to set up and can be used to quickly test any new combination of elements researchers come up with.»


Author: Hayley Dunning | Source: Imperial College London [July 30, 2019]



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Decoding the complex life of a simple parasite

Dicyemids, microscopic parasites comprised of 30 cells, are in-between creatures. With their basic three-part body plan, they are more complex than single-celled protozoans but considerably less complex than multicellular metazoans — the animals of the kingdom Animalia. Yet the simple makeup of these so-called mesozoans does not translate to a simple life. For example, dicyemids eliminate genes to conserve energy and change how they sexually reproduce.











Decoding the complex life of a simple parasite
Researchers at Okinawa Institute of Science and Technology Graduate University (OIST) and Osaka University report
the genome sequence of the parasite, dicyemid, in a study published in Genome Biology and Evolution.
The parasite is comprised of only 30 cells and is found in the renal sacs of octopuses
and other cephalopods [Credit: OIST]

Growing up in the renal sac of an octopus doesn’t sound all that luxurious, but for a dicyemid, it’s an all-inclusive home. In the sac they can feed on urine and reproduce asexually and sexually. When population becomes too dense in the sac, dicyemids become sexual. The larvae produced sexually vary from the larvae produced by asexual reproduction — sexual larvae leave the host in search of a new octopus to call home, and once a new host is found, the cycle continues. However, scientists are still not sure why this simple organism has such a complex lifestyle.


Researchers at Okinawa Institute of Science and Technology Graduate University (OIST) and Osaka University have decoded the genome sequence of dicyemids, providing key insight into the parasites’ not-so-simple lifestyle. The study, published in Genome Biology and Evolution, will help shed light on some of these mysteries.


Prof. Nori Satoh of the OIST Marine Genomics Unit and former PhD student Dr. Tsai-Ming Lu collaborated with renowned dicyemid researcher, Dr. Hidetaka Furuya of Osaka University to sequence the parasite.


The research began in Osaka, where the scientists went to the local fish market and purchased live octopuses. The sourced cephalopods were then brought to the lab, where the scientists collected their urine using a pipette.


They then extracted dicyemids from the urine, carefully removing octopus cells to make sure the samples were pure.


«We rinsed the cells with saltwater and separated them out,» Lu said. «This was repeated several times to remove as many cells of the octopus as we could. Finally, we picked up dicyemid individuals one by one under the microscope to obtain the samples for sequencing.»


Even with this cleaning step, however, obtaining a pure sample of dicyemids was a challenge.


«It is really difficult to exclude all octopus cells from dicyemid samples; however, to obtain a pure sample from the octopus is much easier, so we extracted the genomic DNA,» Lu said.


This obstacle added two years of work to the study, but the researchers ultimately got a clear result: They sequenced the genomes of both organisms and — because the octopus genome has already been sequenced, they were able to extract it out to obtain the sequence of the parasite.


The team found that the dicyemid genome is highly reduced compared to other parasites. For example, these parasites have just four so-called Hox genes, which are responsible for building an organism’s body-plan. These genes are groups of related genes. The groups are usually organized, but that isn’t the case for dicyemids. Scientists found disorganized clusters of genes possibly due to how dicyemids can eliminate genes for energy conservation. They remove genes in their metabolic, immune, and nervous systems.


«Hox genes are important elements in building complicated animal bodies,» Furuya said. «If genomes of many parasites are sequenced, that accumulated genome information can possibly reveal parasites specific gene organization.»


Every animal on Earth has parasites, and while some are simple, others are not. The complete genome sequence of dicyemids not only answers some big questions in dicyemid biology but also offers insights into the evolution of parasites.


Source: Okinawa Institute of Science and Technology Graduate University [July 30, 2019]



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Ancient plankton help researchers predict near-future climate

The Mauna Loa Observatory in Hawai’i recently recorded the highest concentration of carbon dioxide, or CO2, levels in human history. In fact, the last time CO2 levels surpassed 400 parts per million was during the Pliocene, a geological epoch between two and five million years ago, when oceans surged 50 feet higher and small icecaps barely clung to the poles.











Ancient plankton help researchers predict near-future climate
A wood engraving by Eduard Riou depicts a landscape view of the Pliocene.
The image was etched in the late 1800s, when CO2 levels hovered
around 295 ppm [Credit: Welcome Library]

«The Pliocene wasn’t a world that humans and our ancestors were a part of,» said University of Arizona associate professor of geosciences Jessica Tierney. «We just started to evolve at the end of it.»


Now that we’ve reached 415 parts per million CO2, Tierney thinks the Pliocene can be used to understand the climate shifts of the very near future. Past studies attempted this, but a nagging discrepancy between climate models and fossil data from that part of Earth’s history muddled any potential insights.


A new study, published in Geophysical Research Letters, used a different, more reliable type of fossil data than past studies. Tierney is the lead on the study, which resolved the discrepancy between fossil data and climate model simulations and showed that, yes, the Pliocene is a good analog for future climate predictions.


The Pliocene Problem


Before the industrial revolution, CO2 levels hovered around 280 ppm. For perspective, it took over two million years for CO2 levels to naturally decline from 400 ppm to pre-industrial levels. In just over 150 years, humanity has caused those levels to rebound.


Past proxy measurements of Pliocene sea surface temperatures led scientists to conclude that a warmer Earth caused the tropical Pacific Ocean to be stuck in an equatorial weather pattern called El Nino.


Normally, as the trade winds sweep across the warm surface waters of the Pacific Ocean from east to west, warm water piles up in the eastern Pacific, cooling the western side of the ocean by about 7 to 9 degrees Fahrenheit. But during an El Nino, the temperature difference between the east and west drops to just under 2 degrees, influencing weather patterns around the world, including Southern Arizona. El Ninos typically occur about every three to seven years, Tierney said.


The problem is, climate models of the Pliocene, which included CO2 levels of 400 ppm, couldn’t seem to simulate a permanent El Nino without making funky, unrealistic changes to model conditions.


«This paper was designed to revisit that concept of the permanent El Nino and see if it really holds up against a reanalysis of the data,» she said. «We find it doesn’t hold up.»


Fat Thermometers


About 20 years ago, scientists found they could deduce past temperatures based on chemical analysis of a specific kind of fossilized shell of a type of plankton called foraminifera.


«We don’t have thermometers that can go to the Pliocene, so we have to use proxy data instead,» Tierney said.


Since then, scientists have learned that foraminifera measurements can be skewed by ocean chemistry, so Tierney and her team instead used a different proxy measurement — the fat produced by another plankton called coccolithophores. When the environment is warm, coccolithophores produce a slightly different kind of fat than when it’s cold, and paleoclimatologists like Tierney can read the changes in the fat, preserved in ocean sediments, to deduce sea-surface temperatures.


«This is a really commonly used and reliable way to look at past temperatures, so a lot of people have made these measurements in the Pliocene. We have data from all over the world,» she said. «Now we use this fat thermometer that we know doesn’t have complications, and we’re sure we can get a cleaner result.»


El Nin…Nope


Tierney and her team found that the temperature difference between the eastern and western sides of the Pacific did decrease, but it was not pronounced enough to qualify as a full-fledged permanent El Nino.


«We didn’t have a permanent El Nino, so that was a bit of an extreme interpretation of what happened,» she said. «But there is a reduction in the east-west difference — that’s still true.»


The eastern Pacific got warmer than the western, which caused the trade winds to slacken and changed precipitation patterns. Dry places like Peru and Arizona might have been wetter. These results from the Pliocene agree with what future climate models have predicted, as a result of CO2 levels reaching 400 ppm.


This is promising because now the proxy data matches the Pliocene climate models. «It all checks out,» Tierney said.


The Pliocene, however, was during a time in Earth’s history when the climate was slowly cooling. Today, the climate is getting hotter very quickly. Can we really expect a similar climate?


«The reason today sea levels and ice sheets don’t quite match the climate of the Pliocene is because it takes time for ice sheets to melt,» Tierney said. «However, the changes in the atmosphere that happen in response to CO2 — like the changes in the trade winds and rainfall patterns — can definitely occur within the span of a human life.»


Author: Mikayla Mace | Source: University of Arizona [July 31, 2019]



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NASA Scientist to Discuss “Cosmic Explosions and Cosmic Accelerators” at Library of...

Recently, astronomers have been able to coordinate observations of multiple “messengers” from the same event, such as merging neutron stars (background) that produced both gamma rays detected by NASA’s Fermi Gamma-ray Space Telescope (right) and gravitational waves detected by the Laser Interferometer Gravitational-Wave Observatory on Aug. 17, 2017. NASA Goddard’s Dr. Regina Caputo will discuss the burgeoning field of multimessenger astronomy. Credits: NASA/Frank Reddy



The public is invited to a free lecture called ‘Cosmic Explosions and Cosmic Accelerators: Gamma-rays and Multi-messenger Astronomy,’ with Dr. Regina Caputo, NASA research scientist. The talk will occur in the Pickford Theater, third floor, Madison Building, 101 Independence Avenue SE, Library of Congress, Washington, D.C., on Thursday, August 8 from 11:30 a.m. to 12:30 p.m. EDT.


Dr. Caputo works at NASA’s Goddard Space Flight Center in Greenbelt, Md. on the NASA Fermi Gamma Ray Space Telescope team with data from the Fermi Large Area Telescope instrument to study. She is interested in dark matter searches, searches for new physics and all the astrophysics one must understand before discovering something new. She is also working on future gamma-ray instruments.


Astronomical processes, such as supernovae or gamma ray bursts, give off a variety of messenger signals. Astronomers observing these signals can get different information from different signals, and recently, by coordinating their observations of multiple messengers from the same event, they have begun to revolutionize our understanding of the extreme universe. Dr. Regina Caputo will discuss these jointly observed messengers and the contribution of the Fermi Gamma-ray Space Telescope at the forefront of this new era of astronomy.


She is a speaker in the 2019 NASA Goddard Lectures Series at the Library of Congress. Earlier talks in the NASA series included the topics of space weather, improved global water security and sustainability, how Mars has changed over time, NASA’s Hubble Space Telescope and the upcoming James Webb Space Telescope.


The Library of Congress maintains one of the largest and most diverse collections of scientific and technical information in the world. The Library of Congress is the nation’s oldest federal cultural institution and the largest library in the world and holds nearly 151.8 million items in various languages, disciplines and formats. The Library serves both Congress and the nation online and on-site in its reading rooms on Capitol Hill.

For inquiries about this or upcoming talks at the Library of Congress, the public can contact the library’s Science, Technology and Business Division at 202-707-5664. ADA accommodations should be requested five business days in advance at 202-707-6382 (voice/tty) or ada@loc.gov.


The lecture will be later broadcast on the library’s webcast page and YouTube channel “Topics in Science” playlist.

For directions, visit: http://www.loc.gov/visit/maps-and-floor-plans/ or www.loc.gov


For information about Dr. Caputo, visit: https://science.gsfc.nasa.gov/sed/bio/regina.caputo


For NASA’s Fermi website, visit: www.nasa.gov/fermi



Contact:


Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-4044
Robert.j.gutro@nasa.gov


Stephanie Marcus
Library of Congress, Washington
202-707-1192
smar@loc.gov


Editor: Karl Hille





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Satellite with Swiss equipment ready to fly


ESA — EDRS Mission logo.


August 2, 2019


EDRS-C will go into orbit Tuesday from the European Space Center in Kourou, French Guiana. Ruag Space provides several elements of the craft.



ARIANESPACE — Ariane 5 Flight VA249 Mission poster

The Ariane 5 rocket will take off next Tuesday to launch a satellite to make data transmission faster and better. Ruag Space provides onboard computer, thermal insulation and solar reflectors that dissipate heat.


The European Space Agency (ESA) Data Relay Satellite System (EDRS) aims to enable faster and better data transmission between satellites and ground stations. It is the most advanced laser communication network to date and helps Earth observation satellites transmit large amounts of data to Europe almost in real time.



Data Relay Satellite System (EDRS)

EDRS-C is the first satellite of this program. It will be launched from the European Space Center at Kourou, French Guiana. The launcher launcher’s payload cap is provided by Ruag Space, the company said Friday in a statement.



EDRS-C Space Data Highway

This structure offers various protections. It protects against the inclement weather on the firing point, the acoustic effects after ignition of the engines, the resistance of the air and the heat of friction in flight. It is abandoned at an altitude of about 110 kilometers.


Solar reflectors


The EDRS-C satellite also benefits from protection against heat and cold in the space developed by Ruag. The insulation consists of several layers of a metallized polyimide sheet. Each layer is thinner than a human hair.



EDRS-C

Ruag Space’s optical solar reflectors provide the satellite with additional thermal protection. These mirrors help the satellite dissipate the excessive heat it generates in space. Insulation and reflectors were produced in Austria. Ruag also supplies the EDRS-C onboard computer. It controls and monitors the payload of the satellite and many other subsystems.


Ruag Space is the space division of the Swiss technology group Ruag. It employs more than 1,300 people in 13 locations in Switzerland, Sweden, Germany, Finland, USA and Austria.


Related links:
 
European Space Agency (ESA): http://www.esa.int/ESA


EDRS: http://www.esa.int/Our_Activities/Telecommunications_Integrated_Applications/EDRS


Arianespace: http://www.arianespace.com/mission/ariane-flight-va249/


Ruag Space: https://www.ruag.com/en/products-services/space


Images, Video, Text, Credits: ATS/Arianespace/ESA/Airbus/Ruag Space/Orbiter.ch Aerospace/Roland Berga.


Best regards, Orbiter.chArchive link


3-D Bioprinting, Grip Studies on Station May Benefit Earth and Space Systems


ISS — Expedition 60 Mission patch.


August 2, 2019


The Expedition 60 crewmembers are busy conducting new and advanced science experiments today aboard the International Space Station. A U.S. space freighter will begin its secondary mission after it departs the station on Tuesday.


3-D bioprinting in space may become a viable platform in the future for fabricating human organs. NASA astronaut Christina Koch activated the new BioFabrication Facility in the morning testing its ability to print cells.



Image above: Expedition 60 Flight Engineer Christina Koch of NASA works with the BioFabrication Facility that will soon be tested for its ability to print organ-like tissues. Image Credit: NASA.


Flight Engineer Nick Hague is researching the thermophysical properties of ultra-heated materials in microgravity and installed samples into the Electrostatic Levitation Furnace. He then fueled up the Bioculture System to support the Cell Science-02 bone healing and tissue regeneration study.


Hague and Koch are also training for next week’s robotic release of the Cygnus space freighter after 109 days in space. Cygnus will depart the station Tuesday and eject a set of CubeSats for space research after it reaches a safe distance from the station. The commercial cargo craft will orbit Earth for a few months of systems tests and nanosatellite deployments before its fiery, but safe atmospheric destruction above the Pacific Ocean.



International Space Station (ISS). Animation Credit: NASA

Flight Engineers Andrew Morgan and Luca Parmitano continued to explore how microgravity affects their ability to grip and manipulate objects. The GRIP study, from the European Space Agency, may inform the design of future spacecraft control devices and interfaces.


Commander Alexey Ovchinin and Flight Engineer Alexander Skvortsov continue configuring the new Progress 73 resupply ship and offloading its new cargo. The duo also took turns servicing Russian science hardware and life support systems.


Related links:


Expedition 60: https://www.nasa.gov/mission_pages/station/expeditions/expedition60/index.html


BioFabrication Facility: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7599


Electrostatic Levitation Furnace: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1536


Bioculture System: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1049


Cell Science-02: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1676


Cygnus space freighter: https://blogs.nasa.gov/spacestation/2019/04/19/cygnus-cargo-craft-attached-to-station-until-july/


GRIP: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1188


Progress 73 resupply ship: https://go.nasa.gov/2GDbLZA


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


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


Image (mentioned), Animation (mentioned), Text, Credits: NASA/Norah Moran.


Best regards, Orbiter.chArchive link


CERN and ESA forge closer ties through cooperation protocol


CERN — European Organization for Nuclear Research logo.


August 2, 2019



LHC and Space. (Image: CERN)

A new collaboration agreement between CERN and ESA, signed on 11 July, will address the challenge of operating in harsh radiation environments, which are found in both particle-physics facilities and outer space. The agreement concerns radiation environments, technologies and facilities with potential applications in both space systems and particle-physics experiments or accelerators.


This first implementing protocol of CERN-ESA bilateral cooperation covers a broad range of activities, from general aspects such as coordination, financing and personnel exchange, to a list of irradiation facilities for joint R&D activities. It also states the willingness of both organisations to support PhD students working on radiation subjects of common interest.



Image above: Franco Ongaro, Director of Technology, Engineering and Quality and Head of ESTEC, European Space Agency (left) with Eckhard Elsen, CERN Director for Research and Computing (Image: Julien Ordan/CERN).


The agreement identifies seven specific high-priority projects: high-energy electron tests; high-penetration heavy-ion tests; assessment of EEE commercial components and modules (COTS); in-orbit technology demonstration; “radiation-hard” and “radiation-tolerant” components and modules; radiation detectors, monitors and dosimeters; and simulation tools for radiation effects.


In some cases, important preliminary results have already been achieved: high-energy electron tests for the JUICE mission were performed in the CLEAR/VESPER facility to simulate the environment of Jupiter. Complex components were also tested with xenon and lead ions in the SPS North Area at CERN for an in-depth analysis of galactic cosmic-ray effects. These activities will continue and the newly identified ones will be implemented under the coordination of the CERN-ESA Committee on Radiation Issues.


Note:


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.


The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.


Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.


European Space Agency (ESA): http://www.esa.int/ESA


For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/


Images (mentioned), Text, Credit: European Organization for Nuclear Research (CERN).


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Say hello to globular cluster 47 Tucanae 👋This glittery spray of…


Say hello to globular cluster 47 Tucanae 👋


This glittery spray of ancient stars is about 16,700 light-years away from Earth toward the constellation Tucana. Globular clusters like this one are isolated star cities, home to hundreds of thousands of stars that are held together by their mutual gravity. And like the fast pace of cities, there’s plenty of action in these stellar metropolises. The stars are in constant motion, orbiting around the cluster’s center.


Past observations have shown that the heavyweight stars tend to crowd into the “downtown” core area, while lightweight stars reside in the less populated suburbs. But as heavyweight stars age, they rapidly lose mass, cool down and shut off their nuclear furnaces. After the purge, only the stars’ bright, superhot cores – called white dwarfs – remain. This weight loss program causes the now lighter-weight white dwarfs to be nudged out of the downtown area through gravitational interactions with heftier stars.


Until these Hubble observations, astronomers had never seen the dynamic conveyor belt in action. The Hubble results reveal young white dwarfs amid their leisurely 40-million-year exodus from the bustling center of the cluster.


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


Egypt unveils Graeco-Roman era building in North Sinai

An Egyptian archaeological mission unearthed on Wednesday a Graeco-Roman huge building made of red brick and limestone in the province of North Sinai, the country’s Antiquities Ministry said in a statement.











Egypt unveils Graeco-Roman era building in North Sinai
Credit: Egypt. Ministry of Antiquities

«The building was most probably used as a headquarters for the Senate Council of Pelusium, one of the North Sinai’s old cities,» said Mostafa Waziri, secretary-general of the Supreme Council of Antiquities.











Egypt unveils Graeco-Roman era building in North Sinai
Credit: Egypt. Ministry of Antiquities

The initial studies conducted on the architectural planning and the construction of the building indicated that it was used to hold meetings for the citizens’ representatives during the rule of the Ptolemies and Romans for taking important decisions about the public affairs of the city and its citizens, Waziri said.











Egypt unveils Graeco-Roman era building in North Sinai
Credit: Egypt. Ministry of Antiquities

Ayman Ashmawy, head of the Egyptian Antiquities Department at the Ministry of Antiquities, said the 2,500-square-metre building shaped from outside as a rectangular, with circular terraces and a main gate located in the eastern side.











Egypt unveils Graeco-Roman era building in North Sinai
Credit: Egypt. Ministry of Antiquities

He pointed out that the interior design of the building consists of the remains of three 60 cm-thick circular benches which were built of red brick and covered with marble. The mission also uncovered the main streets of Pelusium city, Ashmawy added.











Egypt unveils Graeco-Roman era building in North Sinai
Credit: Egypt. Ministry of Antiquities

He explained that during the fifth and sixth century AD, the building was used as a quarry where the stones, bricks and columns were extracted from their original places for use in the construction of other buildings in the city.


Source: Xinhua News Agency [July 31, 2019]



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