пятница, 5 июля 2019 г.

Space Station Science Highlights: Week of July 1, 2019


ISS — Expedition 60 Mission patch.


July 5, 2019



International Space Station (ISS). Animation Credit: NASA

Crew members aboard the International Space Station conducted scientific investigations last week that tracked radiation, studied heat transfer in space and supported future explorations. The current crew includes Expedition 60 Commander Alexey Ovchinin of Roscosmos and NASA astronauts Nick Hague and Christina Koch. NASA astronaut Andrew Morgan, Alexander Skvortsov of the Russian space agency Roscosmos, and Luca Parmitano of the European Space Agency (ESA) are scheduled to join them on July 20 – the 50th anniversary of the Apollo 11 Moon landing. Research on the space station supports Artemis, NASA’s program to return humans to the Moon and establish a sustained presence there.


Here are details on some of the science conducted on the orbiting lab during the week of July 1:


A direct line to the space station



Image above: During an ISS HAM radio session, NASA astronaut Nick Hague answers questions from students on the ground. Image Credit: NASA.


Crew members conducted an ISS Ham session last week. Using amateur or ham radio, groups of students talk directly to the crew aboard the space station when it passes overhead. The students learn about the space station, radio waves, and other science and engineering topics and prepare questions before their scheduled calls. Hundreds more listen in from classrooms or auditoriums. This real-time contact with the orbiting lab sparks interest in science, technology, engineering and mathematics and inspires the next generation of explorers.


Tracking neutron radiation


The RADI N2 investigation seeks to better characterize the neutron radiation environment aboard the space station using bubble detectors attached to fixed locations and carried by crew members. The data could help define the risk that this type of radiation poses to crew members and support development of advanced protective measures for future spaceflight. The crew continued to deploy detectors on the space station last week.


A better way to keep cool



Image above: NASA astronaut Christina Koch demonstrates behavior of fluids in the microgravity environment aboard the International Space Station. Image Credit: NASA.


Last week, the crew conducted a session for the Two Phase Flow investigation, which examines the heat transfer characteristics of flow boiling in microgravity. Boiling removes heat by turning liquid into vapor at the heated surface. Returning that vapor to a liquid by way of a condenser creates a cooling system. In microgravity, though, liquid and bubble behaviors differ drastically from that on Earth. The investigation creates a database on the heat transfer efficiency of liquids in space that can inform design of thermal management systems for future spacecraft. It also can support development of improved cooling systems for hybrid cars and other electronics systems that generate high heat in small spaces on Earth.


Meeting the demand for small satellites



Image above: The sun glints off the Celebes Sea of Southeast Asia in this image captured as the space station flew 225 miles above Indonesia. Image Credit: NASA.


Crew members installed the NanoRacks External Cygnus CubeSat Deployer (extCygnus NRCSD), a stackable, modular case for launching small satellites. Each deployer accommodates up to eight launch cases, helping to meet the growing demand for this type of satellite for a variety of customers. The extCygnus NRCSD releases CubeSats from the Cygnus resupply vehicle after it completes its resupply mission and leaves the space station.


Other investigations on which the crew performed work:


— The Veg-04A investigation focuses on how light quality and fertilizer affect growth of Mizuna mustard, a leafy green crop, as part of an effort to develop the capability to produce fresh food in space. It also looks at microbial food safety, nutritional value, taste acceptability by the crew, and the overall behavioral health benefits of having plants and fresh food in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7896


— Team Task Switching looks at whether crew members have difficulty switching from one task to another and the effects of such switches to reduce negative consequences and improve individual and team motivation and effectiveness: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7538


— 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


— Standard Measures captures a consistent and simple set of measures from crew members throughout the ISS Program to characterize adaptive responses to and risks of living in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7711



Space to Ground: On the Bubble: 07/05/2019

Related links:


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


ISS Ham: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337


RADI N2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=874


Two Phase Flow: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1034


NanoRacks External Cygnus CubeSat Deployer (extCygnus NRCSD): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=2015


ISS National Lab: https://www.issnationallab.org/


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


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


Best regards, Orbiter.chArchive link


800-year-old tomb found in northern China

A brick and stone tomb dating back over 800 years has recently been discovered in Yuanqu County, northern China’s Shanxi Province.











800-year-old tomb found in northern China
Credit: Boatou Daily News/Wang Feihang

The tomb was found near a nonferrous metal company office building during a tap water facility renovation project. Researchers, after evaluation, decided it was constructed during the Song and Jin dynasties (960-1234), according to the culture and tourism bureau of Yuanqu.
Some burial items including pots and porcelain bowls were unearthed in the tomb, about three meters underground.











800-year-old tomb found in northern China
Credit: Boatou Daily News/Wang Feihang











800-year-old tomb found in northern China

Credit: Boatou Daily News/Wang Feihang



«The tomb is well-preserved without marks of flooding, collapse or robbery,» deputy director of the county’s culture and tourism bureau Hou Xiaochao said. «It should be a couple’s joint tomb built some 800 years ago.»


Hou said the discovery is of great value to the study of the burial customs, lifestyle, architecture, clothes and craftsmanship at that time.


Source: Xinhua News Agency [June 27, 2019]



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6,000-year-old cave paintings discovered in Czech Republic

Archaeologists have discovered the oldest paintings on Czech territory. They seem to have been made using charcoal more than 6,000 years ago in a Moravian cave. A common place for scribbling messages, they were undetected until now, hidden among many other drawings made in latter periods.











6,000-year-old cave paintings discovered in Czech Republic
Credit: Petr Zajíček

The Catherine Cave lies just a few kilometres from the Moravian capital of Brno. It has been a popular place to visit for thousands of years, and its walls are littered by many scribbled pictures and messages, from various ages.


It is for this reason that its most ancient message may have been overlooked, says speleologist Petr Zajíček, who made the discovery with his colleague Martin Golec, an archaeologist from the Palacký University in Olomouc.


It all started when Dr. Golec got inkling that the Catherine Cave may be hiding something very old, says Mr. Zajíček.


“Dr. Golec had a feeling there could be something there. He is also a member of a group researching the nearby Býčí Skála cave, where one pre-historic painting was already found. He thought that since this cave was also settled in the pre-historic era, there was a chance one could find something here. So I let him in, we studied the walls and found them. They are actually quite visible, but no one attributed much importance to them before.”


More abstract scribbles than paintings, the drawings were likely made with pieces of charcoal from the cave dwellers’ fireplace, the research team believes.


Remains and artefacts have proven that the Catherine Cave was inhabited by humans during the Neolithic Era some 6,200 years ago. The carbon dating test results support the hypothesis that the drawings come from this period.











6,000-year-old cave paintings discovered in Czech Republic
Credit: Petr Zajíček

Mr. Zajíček and the research team believe that the drawings were made as the humans were exploring the depths of the cave.


“We presume that the people who were using the massive portal and the cave behind it as a settlement where they lived explored the further passages and that the reflecting light from their torches onto the rocks may have evoked images in their mind, such as those of a woman’s womb, or various types of animals.


“Dr. Golec believes that as a consequence they then marked these places. It is hard for us to deduce what these could mean, but it seems it may also have had a ritual motive.”


The area of Moravia seems to have been a popular area for settlement among hunter-gatherers during the Stone Age, as discoveries from other caves have shown. Remains of even older human settlements, the earliest to be found in Central Europe, have been discovered in the Mladečské caves, near Olomouc. However, no paintings have yet been found there, says Mr. Zajíček.


Although the oldest paintings yet discovered in Czech lands, the Catherine Cave drawings are still far younger than the oldest cave paintings ever found, which lie in the Lascaux cave in France and are believed to have been made 17,000 years ago.


Still, the discovery is a major one in the regional context, and preparations are underway for making the drawings available to view by visitors of the cave complex.


“We are thinking about how to present them to visitors of the cave, who pass on the sightseeing route. At the very least, we want to make high quality photograph copies accompanied by tables in Czech and English, available for people to look at on the route.”


Author: Tom McEnchroe | Source: Radio Praha [June 28, 2019]



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Roman gemstones, shoe and gaming board uncovered at Vindolanda fort

Two rare Roman gemstones that had fallen down a toilet and a 2,000 year-old gaming board have been unearthed at a Northumberland fort.











Roman gemstones, shoe and gaming board uncovered at Vindolanda fort
It is thought these carved intaglios carnelian and red jasper gemstones are
of the Gods Minerva and Apollo [Credit: The Vindolanda Trust]

The treasures found at Vindolanda in Hexham, near Hadrian’s Wall, were dug up by a team of 400 volunteers and have been sent for analysis.


As well as the 1,800-year-old gems, a soldier’s size 11 shoe was also found.


A trust spokesman said the gems were precious but the glue used to fix them in rings was not strong enough.


Dr Andrew Birley, chief executive officer at the Vindolanda Trust, said: «The rather beautiful gem stones often depicted a god or goddess who were special to the owner.











Roman gemstones, shoe and gaming board uncovered at Vindolanda fort
Shoes were made from cow hide and goat skin and had hobnail studs making them sturdy to cope
with the northern terrain, a trust spokesman said [Credit: The Vindolanda Trust]

«Although carefully made by skilled artisans and prized by their owners, the glue that secured them in rings had a nasty habit of failing.


«These stones were recovered from the Third Century bath house toilet drain — their owners either did not initially notice that their gemstones had fallen out of the rings and into the loo or they could not face climbing down into the toilet to try to recover them.»


Dr Birley said another great find was a cracked, gaming board that was used in the bath house at Vindolanda, one of 14 forts along Hadrian’s Wall.


«The Romans played a very tactical game which looked a little like draughts and was called little soldiers or Ludus latrunculorum,» he said.











Roman gemstones, shoe and gaming board uncovered at Vindolanda fort
Roman gaming board discovered at Vindolanda earlier this year
[Credit: The Vindolanda Trust]

«Gaming boards and counters are particularly prevalent on Roman military sites and shows that it was not all work in Roman times.


«Like today, gaming was an important part of life for many people 2,000 years ago.»


The finds are being analysed and will eventually go on display at the fort’s museum.


Source: BBC News Website [June 29, 2019]



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2019 July 5 La Silla Eclipse Sequence Image Credit &…


2019 July 5


La Silla Eclipse Sequence
Image Credit & Copyright: Petr Horálek


Explanation: The road to the high mountaintop La Silla Observatory in the Chilean Atacama Desert also led in to the path of July 2nd’s total solar eclipse. Recorded at regular intervals before and after the total eclipse phase, the frames in this composite sequence include the moment the Moon’s dark shadow fell across some of planet Earth’s advanced large telescopes. The dreamlike view looks west toward the setting Sun and the approaching Moon shadow. In fact La Silla was a little north of the shadow track’s center line, so the region’s stunning, clear skies are slightly brighter to the north (right) in the scene.


∞ Source: apod.nasa.gov/apod/ap190705.html


X-rays Spot Spinning Black Holes Across Cosmic Sea




Q2237+0305


Credit: NASA/CXC/Univ. of Oklahoma/X. Dai et al.








Like whirlpools in the ocean, spinning black holes in space create a swirling torrent around them. However, black holes do not create eddies of wind or water. Rather, they generate disks of gas and dust heated to hundreds of millions of degrees that glow in X-ray light.


Using data from NASA’s Chandra X-ray Observatory and chance alignments across billions of light years, astronomers have deployed a new technique to measure the spin of five supermassive black holes. The matter in one of these cosmic vortices is swirling around its black hole at greater than about 70% of the speed of light. 


The astronomers took advantage of a natural phenomenon called a gravitational lens. With just the right alignment, the bending of space-time by a massive object, such as a large galaxy, can magnify and produce multiple images of a distant object, as predicted by Einstein.


In this latest research, astronomers used Chandra and gravitational lensing to study five quasars, each consisting of a supermassive black hole rapidly consuming matter from a surrounding accretion disk. Gravitational lensing of the light from each of these quasars by an intervening galaxy has created multiple images of each quasar, as shown by these Chandra images of four of the targets. The sharp imaging ability of Chandra is needed to separate the multiple, lensed images of each quasar.


The key advance made by researchers in this study was that they took advantage of «microlensing,» where individual stars in the intervening, lensing galaxy provided additional magnification of the light from the quasar. A higher magnification means a smaller region is producing the X-ray emission.


The researchers then used the property that a spinning black hole is dragging space around with it and allows matter to orbit closer to the black hole than is possible for a non-spinning black hole. Therefore, a smaller emitting region corresponding to a tight orbit generally implies a more rapidly spinning black hole. The authors concluded from their microlensing analysis that the X-rays come from such a small region that the black holes must be spinning rapidly. 


The results showed that one of the black holes, in the lensed quasar called the «Einstein Cross,» (labeled Q2237 in the image above) is spinning at, or almost at, the maximum rate possible. This corresponds to the event horizon, the black hole’s point of no return, spinning at the speed of light, which is about 670 million miles per hour. Four other black holes in the sample are spinning, on average, at about half this maximum rate. 


For the Einstein Cross the X-ray emission is from a part of the disk that is less than about 2.5 times the size of the event horizon, and for the other 4 quasars the X-rays come from a region four to five times the size of the event horizon.


How can these black holes spin so quickly? The researchers think that these supermassive black holes likely grew by accumulating most of their material over billions of years from an accretion disk spinning with a similar orientation and direction of spin, rather than from random directions. Like a merry-go-round that keeps getting pushed in the same direction, the black holes kept picking up speed. 


The X-rays detected by Chandra are produced when the accretion disk surrounding the black hole creates a multimillion-degree cloud, or corona above the disk near the black hole. X-rays from this corona reflect off the inner edge of the accretion disk, and the strong gravitational forces near the black hole distort the reflected X-ray spectrum, that is, the amount of X-rays seen at different energies. The large distortions seen in the X-ray spectra of the quasars studied here imply that the inner edge of the disk must be close to the black holes, giving further evidence that they must be spinning rapidly.


The quasars are located at distances ranging from 9.8 billion to 10.9 billion light years from Earth, and the black holes have masses between 160 and 500 million times that of the sun. These observations were the longest ever made with Chandra of gravitationally lensed quasars, with total exposure times ranging between 1.7 and 5.4 days.


A paper describing these results is published in the July 2nd issue of The Astrophysical Journal, and is available online. The authors are Xinyu Dai, Shaun Steele and Eduardo Guerras from the University of Oklahoma in Norman, Oklahoma, Christopher Morgan from the United States Naval Academy in Annapolis, Maryland, and Bin Chen from Florida State University in Tallahassee, Florida.


NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.





Source: NASA’s Chandra X-ray Observatory



Fast Facts for Q2237+0305:

Scale: Image is 18 arcsec across. (About 500,000 light years)
Category: Quasars & Active Galaxies
Coordinates (J2000): RA 22h 40m 30.34s | Dec 03° 21´ 28.8″
Constellation: Pegasus
Observation Dates: 20 pointings from Dec 31, 2009 to Jun 6, 2014
Observation Time: 130 hours
Obs. IDs: 11534-11539, 13191, 13195, 12831-12832, 13960-13961, 14513-14518, 16316-16317
Instrument: ACIS
References: Dai, X. et al. 2019, AJ, 879, 35arXiv:1901.06007
Color Code: X-ray intensity: purple
Distance Estimate: About 9.8 billion light years (z=1.69)



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‘Arwald: the last Pagan Jutish King’ artwork by artist, Hannah George, Isle...

‘Arwald: the last Pagan Jutish King’ artwork by artist, Hannah George, Isle of Wight.



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KWISP detector searches for dark energy from the Sun


CERN — European Organization for Nuclear Research logo.


4 July, 2019


First results are in for the KWISP detector’s hunt for hypothetical dark-energy particles from the Sun



Image above: The KWISP detector is looking for hypothetical “chameleon” particles that could be causing the universe to expand at an accelerating rate. (Image: NASA, ESA, H.Teplitz and M.Rafelski (IPAC/Caltech), 
A. Koekemoer (STScI), R. Windhorst (ASU), Z. Levay (STScI).


Astronomers observe that the universe is expanding at an accelerating rate, but what causes this acceleration is unknown. A form of energy known as dark energy is the most popular explanation, and is keeping scientists the world over occupied searching for it. Now, a team of researchers working with the KWISP detector at CERN has presented the first results of their search for hypothetical “chameleon” particles from the Sun that could make up dark energy.


Like their reptilian namesakes, chameleon particles would change depending on their surroundings. In regions of high density, such as on Earth, their mass would be large, and as a result their force would act over short distances. By contrast, in regions of low density, such as in empty space, their mass would be extremely small and their force would be long-ranged. This changing behaviour makes chameleon particles good candidate particles for dark energy, but it also makes them difficult to search for on Earth.


Enter KWISP, a unique detector recently installed at the CAST experiment to sense the force exerted on a thin membrane by a stream of chameleon particles from the Sun. On hitting the membrane, such a hypothetical stream would move it from its normal rest position by less than a proton’s radius – about a quadrillionth of a metre. This tiny displacement would be revealed by light from a laser beam that travels through a special optical configuration that includes the membrane.


The new results from KWISP were obtained with data taken at CAST in July 2017 for about 90 minutes, during which the experiment tracked the Sun. The data were part of a 10-day data-taking campaign to test KWISP. To increase the chances of finding solar chameleons, the team added two elements to the KWISP detector before taking the data: a mirror system to focus the incoming stream of solar chameleons, and a so-called mechanical chopper, placed between the mirror system and the detector, to modulate the force exerted by the stream in a way that maximises the detector’s sensitivity to the particles.


The researchers observed no signal of solar chameleons, but the data allowed them to derive an upper limit on the force exerted on the membrane by the particles of 44 ± 18 piconewtons – about the weight of a single human cell.


Together with theoretical calculations of the number of solar chameleons expected to reach the detector, this upper limit allowed bounds to be placed on the strength of the interactions of solar chameleons with matter and light. These bounds are complementary to those obtained from other experiments, such as the GridPix detector at CAST, which looks for X-ray photons from solar chameleons.


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.


Related links:


KWISP first results: https://arxiv.org/abs/1906.01084


CAST experiment: https://home.cern/science/experiments/cast


GridPix detector at CAST: https://arxiv.org/abs/1808.00066


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


Image (mentioned), Text, Credits: CERN/Ana Lopes.


Best regards, Orbiter.chArchive link


ancientpeopleancientplaces: ‘Cunagussos: Iron Age Wanderer’…











ancientpeopleancientplaces:



‘Cunagussos: Iron Age Wanderer’ Poetry Sequence


Written by The Silicon Tribesman. All rights reserved, 2019.



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