вторник, 18 сентября 2018 г.

2018 September 18 Salt, Pepper, and Ice Video Credit &…


2018 September 18


Salt, Pepper, and Ice
Video Credit & Copyright: Maroun Habib (Moophz)


Explanation: There’s a “camera” comet now moving across the sky. Just a bit too dim to see with the unaided eye, Comet 21P / Giacobini-Zinner has developed a long tail that makes it a good sight for binoculars and sensitive cameras. The movement of the Comet 21P on the sky was captured last week in the featured time-lapse video compressing 90 minutes into about 2.5 seconds. What might seem odd is that the 21P’s tail is not following the comet’s movement. This is because comet tails always point away from the Sun, and the comet was not moving toward the Sun during the period photographed. Visible far in the background on the upper left is the Salt & Pepper star cluster, M37, while the bright red star V440 Auriga is visible just about the frame’s center. This 2-km ball of dust-shedding ice passed its nearest to the Sun and Earth only last week and is now fading as it crosses into southern skies. Comet 21P should remain visible, however, and photogenic to stabilized cameras, for another month or so.


∞ Source: apod.nasa.gov/apod/ap180918.html


10 Things: Why Cassini Mattered

One year ago, on Sept. 15, 2017, NASA’s Cassini spacecraft ended

its epic exploration of Saturn with a planned dive into the planet’s

atmosphere–sending back new science to the last second. The spacecraft is

gone, but the science continues. Here are 10 reasons why Cassini mattered…


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1.

Game Changers


Cassini and ESA (European Space Agency)’s Huygens probe expanded our understanding of the

kinds of worlds where life might exist.


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2. A (Little) Like Home


At Saturn’s largest moon,

Titan, Cassini and Huygens showed us one of the most Earth-like worlds we’ve

ever encountered, with weather, climate and geology that provide new ways to

understand our home planet.


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3. A Time Machine (In a Sense)


Cassini gave us a portal to see the physical processes that likely

shaped the development of our solar system, as well as planetary systems around

other stars.


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4. The Long Run


The length of Cassini’s mission enabled us to observe weather and

seasonal changes over nearly half of a Saturn year, improving our understanding

of similar processes at Earth, and potentially those at planets around other

stars.


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5. Big Science in Small Places


Cassini revealed Saturn’s moons to be unique worlds with their own

stories to tell.


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6. Ringscape


Cassini showed us the complexity of Saturn’s rings and the

dramatic processes operating within them.


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7. Pure Exploration


Some of Cassini’s best discoveries were serendipitous. What

Cassini found at Saturn prompted scientists to rethink their understanding of

the solar system.


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8. The Right Tools for the Job


Cassini represented a staggering achievement of human and

technical complexity, finding innovative ways to use the spacecraft and its

instruments, and paving the way for future missions to explore our solar

system.


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9. Jewel of the Solar System


Cassini revealed the beauty of Saturn, its rings and moons,

inspiring our sense of wonder and enriching our sense of place in the cosmos.


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10. Much Still to Teach Us


The data returned by Cassini during its 13 years at Saturn will

continue to be studied for decades, and many new discoveries are undoubtedly

waiting to be revealed. To keep pace with what’s to come, we’ve created a new

home for the mission–and its spectacular images–at https://solarsystem.nasa.gov/cassini.



Make

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Space Station Science Highlights: Week of September 10, 2018


ISS – Expedition 56 Mission patch.


Sept. 17, 2018


As the Expedition 56 crew continued to await the delayed arrival of Japan’s HTV-7 resupply, scientific operations continued aboard the International Space Station including research on life science and Earth observation.



International Space Station (ISS)

The Japan Aerospace Exploration Agency (JAXA) has postponed the scheduled launch of the HTV-7 resupply vehicle from the Tanegashima Space Center in southern Japan. A new launch date has not yet been determined.


Learn more about the science happening on station below:


Crew members observe Hurricane Florence as it moves toward land


The space station’s unique vantage point makes it an ideal platform for observing and reporting on developing storms. The Tropical Cyclone investigation demonstrates the feasibility of studying these powerful storms from space, which would contribute to alerting populations and governments around the world when a dangerous storm is approaching.



Image above: Astronaut Alexander Gerst of the European Space Agency photographed Hurricane Florence as it headed toward the East Coast of the United States. As the orbital lab flew 250 miles above the storm, the crew captured photo and video of Florence.


Final week of rodent research operations occurs, samples stowed for analysis


Spaceflight has an impact on many human systems. Rodent Research-7 investigates how the microgravity environment of space affects the community of microorganisms in the gastrointestinal tract, or microbiota.


The study also evaluates relationships between system changes, such as sleep-wake cycle disruption, and imbalance of microbial populations. This will aid in identification of contributing factors and support development of countermeasures to protect astronaut health during long-term missions, as well as to improve the treatment of gastrointestinal, immune, metabolic and sleep disorders on Earth.


The investigation’s final operations occurred last week as the crew performed bone densitometer scans and collected and stowed samples in the Minus Eighty Degree Celsius Laboratory Freezer for ISS (MELFI).


New carrier installed in plant biology investigation


Understanding how plants grow and thrive in harsh environments, both on Earth and in space, can contribute to advancements in agriculture. The Advanced Plant Habitat Facility (Plant Habitat) is a fully-automated facility used to conduct plant bioscience research by providing a large, enclosed, environmentally-controlled chamber aboard the space station.



Animation above: The Plant Habitat-1 investigation compares differences in genetics, metabolism, photosynthesis, and gravity sensing between plants grown in space and on Earth. This investigation provides key insights on major changes occurring in plants exposed to microgravity.


Last week, a new science carrier was installed into the Plant Habitat facility. Watering is planned for Tuesday of this week.



Space to Ground: Above the Storm: 09/14/2018

Other work was done on these investigations: Microbial Tracking-2, Glacier, Time Perception, BCAT-CS, ISS HAM, Atomization, Radi-N2, Airway Monitoring, Food Acceptability, Cold Atom Lab, and Team Task Switching.


Related links:


Expedition 56: https://www.nasa.gov/mission_pages/station/expeditions/expedition56/index.html


Tropical Cyclone: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1712


Rodent Research-7: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7425


MELFI: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=56


Plant Habitat: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=2036


Plant Habitat-1: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2032


Microbial Tracking-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1663


Glacier: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=342


Time Perception: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7504


BCAT-CS: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7668


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


Atomization: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=282


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


Airway Monitoring: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1067


Food Acceptability: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562


Cold Atom Lab: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7396


Team Task Switching: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7538


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


Images, Animation, Video, Text, Credits: NASA/Michael Johnson/Yuri Guinart-Ramirez, Lead Increment Scientist Expeditions 55 & 56.


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NASA’s TESS Shares First Science Image in Hunt to Find New Worlds


NASA – TESS Mission logo.


Sept. 17, 2018



Image above: The Transiting Exoplanet Survey Satellite (TESS) took this snapshot of the Large Magellanic Cloud (right) and the bright star R Doradus (left) with just a single detector of one of its cameras on Tuesday, Aug. 7. The frame is part of a swath of the southern sky TESS captured in its “first light” science image as part of its initial round of data collection. Image Credits: NASA/MIT/TESS.


NASA’s newest planet hunter, the Transiting Exoplanet Survey Satellite (TESS), is now providing valuable data to help scientists discover and study exciting new exoplanets, or planets beyond our solar system. Part of the data from TESS’ initial science orbit includes a detailed picture of the southern sky taken with all four of the spacecraft’s wide-field cameras. This “first light” science image captures a wealth of stars and other objects, including systems previously known to have exoplanets.


“In a sea of stars brimming with new worlds, TESS is casting a wide net and will haul in a bounty of promising planets for further study,” said Paul Hertz, astrophysics division director at NASA Headquarters in Washington. “This first light science image shows the capabilities of TESS’ cameras, and shows that the mission will realize its incredible potential in our search for another Earth.”



Image above: Download high-resolution versions of this and other TESS “first light” images from the Scientific Visualization Studio at NASA’s Goddard Space Flight Center. Image Credits: NASA/MIT/TESS.


TESS acquired the image using all four cameras during a 30-minute period on Tuesday, Aug. 7. The black lines in the image are gaps between the camera detectors. The images include parts of a dozen constellations, from Capricornus to Pictor, and both the Large and Small Magellanic Clouds, the galaxies nearest to our own. The small bright dot above the Small Magellanic Cloud is a globular cluster — a spherical collection of hundreds of thousands of stars — called NGC 104, also known as 47 Tucanae because of its location in the southern constellation Toucana, the Toucan. Two stars, Beta Gruis and R Doradus, are so bright they saturate an entire column of pixels on the detectors of TESS’s second and fourth cameras, creating long spikes of light.


“This swath of the sky’s southern hemisphere includes more than a dozen stars we know have transiting planets based on previous studies from ground observatories,” said George Ricker, TESS principal investigator at the Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research in Cambridge.




Images above: The Transiting Exoplanet Survey Satellite (TESS) captured this strip of stars and galaxies in the southern sky during one 30-minute period on Tuesday, Aug. 7. Created by combining the view from all four of its cameras, this is TESS’ “first light,” from the first observing sector that will be used for identifying planets around other stars. Notable features in this swath of the southern sky include the Large and Small Magellanic Clouds and a globular cluster called NGC 104, also known as 47 Tucanae. The brightest stars in the image, Beta Gruis and R Doradus, saturated an entire column of camera detector pixels on the satellite’s second and fourth cameras. Images Credits: NASA/MIT/TESS.


TESS’s cameras, designed and built by MIT’s Lincoln Laboratory in Lexington, Massachusetts, and the MIT Kavli Institute, monitor large swaths of the sky to look for transits. Transits occur when a planet passes in front of its star as viewed from the satellite’s perspective, causing a regular dip in the star’s brightness.


TESS will spend two years monitoring 26 such sectors for 27 days each, covering 85 percent of the sky. During its first year of operations, the satellite will study the 13 sectors making up the southern sky. Then TESS will turn to the 13 sectors of the northern sky to carry out a second year-long survey.


MIT coordinates with Northrop Grumman in Falls Church, Virginia, to schedule science observations. TESS transmits images every 13.7 days, each time it swings closest to Earth. NASA’s Deep Space Network receives and forwards the data to the TESS Payload Operations Center at MIT for initial evaluation and analysis. Full data processing and analysis takes place within the Science Processing and Operations Center pipeline at NASA’s Ames Research Center in Silicon Valley, California, which provides calibrated images and refined light curves that scientists can analyze to find promising exoplanet transit candidates.


TESS builds on the legacy of NASA’s Kepler spacecraft, which also uses transits to find exoplanets. TESS’s target stars are 30 to 300 light-years away and about 30 to 100 times brighter than Kepler’s targets, which are 300 to 3,000 light-years away. The brightness of TESS’ targets make them ideal candidates for follow-up study with spectroscopy, the study of how matter and light interact.



How NASA’s Newest Planet Hunter Scans the Sky

Video above: This animation shows how the Transiting Exoplanet Survey Satellite (TESS) will study 85 percent of the sky in 26 sectors. The spacecraft will observe the 13 sectors that make up the southern sky in the first year and the 13 sectors of the northern sky in the second year. Video Credits: NASA’s Goddard Space Flight Center.


The James Webb Space Telescope and other space and ground observatories will use spectroscopy to learn more about the planets TESS finds, including their atmospheric compositions, masses and densities.


TESS has also started observations requested through the TESS Guest Investigator Program, which allows the broader scientific community to conduct research using the satellite.


“We were very pleased with the number of guest investigator proposals we received, and we competitively selected programs for a wide range of science investigations, from studying distant active galaxies to asteroids in our own solar system,” said Padi Boyd, TESS project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “And of course, lots of exciting exoplanet and star proposals as well. The science community are chomping at the bit to see the amazing data that TESS will produce and the exciting science discoveries for exoplanets and beyond.”


TESS launched from NASA’s Kennedy Space Center in Cape Canaveral, Florida, on April 18 aboard a SpaceX Falcon 9 rocket and used a flyby of the Moon on May 17 to head toward its science orbit. TESS started collecting scientific data on July 25 after a period of extensive checks of its instruments.


TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Dr. George Ricker of MIT’s Kavli Institute for Astrophysics and Space Research serves as principal investigator for the mission. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT’s Lincoln Laboratory in Lexington, Massachusetts; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.


Related links:


TESS Guest Investigator Program: https://heasarc.gsfc.nasa.gov/docs/tess/proposing-investigations.html


TESS (Transiting Exoplanet Survey Satellite): http://www.nasa.gov/tess


NASA’s Deep Space Network: https://www.nasa.gov/directorates/heo/scan/services/networks/dsn


NASA’s Kepler spacecraft: https://www.nasa.gov/mission_pages/kepler/main/index.html


James Webb Space Telescope (JWST): https://www.nasa.gov/mission_pages/webb/main/index.html


Images (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Jeanette Kazmierczak.


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Was this huge river delta on Mars the place where its oceans finally disappeared?

For some time, scientists have known that Mars was once a much warmer and wetter environment than it is today. However, between 4.2 and 3.7 billion years ago, its atmosphere was slowly stripped away, which turned the surface into the cold and desiccated place we know today. Even after multiple missions have confirmed the presence of ancient lake beds and rivers, there are still unanswered questions about how much water Mars once had.











Was this huge river delta on Mars the place where its oceans finally disappeared?
Mars Orbiter image of rock once carved by water [Credit: NASA]

One of the most important unanswered questions is whether or not large seas or an ocean ever existed in the northern lowlands. According to a new study by an international team of scientists, the Hypanis Valles ancient river system is actually the remains of a river delta. The presence of this geological feature is an indication that this river system once emptied into an ancient Martian sea in Mars’ northern hemisphere.


For the sake of their study, titled “The Hypanis Valles delta: The last highstand of a sea on early Mars?” which recently appeared in the journal Earth and Planetary Science Letters, the international team consulted data from the Mars Reconnaissance Orbiter (MRO) and the 2001 Mars Odyssey probe to investigate the morphology, sedimentary architecture, and depositional environment of the Hypanis Valles region.


This delta is what separates the southern highlands from the northern lowlands, where an ancient ocean is once believed to have existed – a theory which has remained unproven. Based on data from the MRO’s High Resolution Imaging Science Experiment (HiRISE) instrument and the 2001 Odyssey’s THermal EMission Imaging System (THEMIS), the team found compelling evidence that a large body of water once covered the northern third of Mars.


As Joel Davis – a postdoctoral researcher in the Planetary Surface Group at the Natural History Museum and a co-author of the paper – explained in a recent NHM press release:


“A Martian ocean means that Mars probably had a very Earth-like water cycle, with rivers, lakes, and now oceans, all of which probably interacted as part of a planet-wide system. We think this Earth-like hydrological cycle was active about 3.7 billion years ago, and started to shut down sometime after that. Our study is not definitive proof for an ocean, but these geological features are very hard to explain without one.”











Was this huge river delta on Mars the place where its oceans finally disappeared?
An image from the study showing the Hypanis Valles sediment fan [Credit: Peter Fawdon et al./
Earth and Planetary Science Letters, 2018]

Determining whether or not Mars had standing bodies of water in the past has been no easy challenge, mainly because Mars lacks the kinds of apparent indications of lakes and oceans on its surface (like fine-grained sand deposits or clear shorelines). As a result, scientists have had to look for other means of identifying where water flowed and sand was deposited, which is where sedimentary fans come into play.


In this case, the fan identified was a river delta, which form when a river slows down in the presence of a slower-moving or still body of water. This causes any small sediments that are being carried by the river to settle on the ground and form geological features (e.g. small islands at the mouth of the river) over time. In the past, river deltas have been found on Mars, but only in craters where water flowed into a lake.


Case in point, the Curiosity rover, which has been studying the Gale Crater since it landed there in 2012, has discovered abundant evidence that the crater was once a lake. This evidence included clay minerals at the base of Mount Sharp, as well as sedimentary deposits and channels discovered in the crater wall and Mount Sharp that could only be explained by water flowing into the crater.


Thanks to their study, scientists can now say with certainty that the Hypanis sedimentary fan is evidence of a standing body of water large enough to be an ocean. Their study also indicates how the ocean retreated as the climate gradually become colder and dryer. Basically, as ocean levels dropped by nearly 500 meters, the Hypanis delta began growing outwards as a result.











Was this huge river delta on Mars the place where its oceans finally disappeared?
Artist rendition of how the “lake” at Gale Crater on Mars may have looked millions of years ago
[Credit: Kevin Gil]

Finally, they determined that roughly 3.6 billion years ago, the water system dried up and disappeared, which is consistent with when Mars lost most of its ancient atmosphere. Since that time, no water has been able to exist on the surface in any form other than ice – with the exception of an underground lake that was recently discovered.


As Dr. Peter Fawdon, a post doctoral research associate from the Open University and the lead author of the study, explained:


“The research has significantly contributed to our understanding of the climate on early Mars, which we now know went from having a water cycle similar to that of Earth to being a cold, desert-like landscape in a relatively short period. We would like to gain a better understanding of how many of these fluvial deltas exist on Mars so that we can determine the position and size of its ancient seas.”


This study has not only provided definitive evidence of their being an ocean on Mars, it is also significant in that the shoreline of this ancient ocean is close to where the ExoMars 2020 and Mars 2020 rovers will be landing in the coming years. The fact that an ocean once existed there increases the odds that these rovers will find evidence of past Martian life – which is their primary goal.











Was this huge river delta on Mars the place where its oceans finally disappeared?
Scientists were able to gauge the rate of water loss on Mars by measuring the ratio of water
and HDO from today and 4.3 billion years ago [Credit: Kevin Gill]

Over the course of the last century, our collective understanding of Mars has changed dramatically. Once thought to be a planet crisscrossed by canals and inhabited by little green men, the first robotic missions to the Red Planet revealed a frozen landscape that was hostile to life. However, in recent decades, evidence has emerged that shows that Mars may have supported life in the past.


And though there may or may not be life there today, Mars remains a dynamic and fascinating place that can teach us much about the history and evolution of our solar system. However, if there are still microbes to be found on the Red Planet, the ExoMars 2020 and the Mars 2020 rovers are likely to be the ones that find it.


Author: Matt Williams | Source: Universe Today [September 14, 2018]



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Archaeologists voice alarm over Artemis Agrotera temple in Athens

Greek archaeologists expressed their concern on Monday over the abandonment by the state of the site of the mid-5th century BC Temple of Artemis Agrotera, which they described as “one of the most historically important archaeological sites in the center of Athens.”











Archaeologists voice alarm over Artemis Agrotera temple in Athens
The Temple of Artemis Agrotera excavation site in 2014 [Credit: artemisargotera.org]

The Ionic-style temple, dedicated to the Greek virgin goddess of the hunt was constructed of Pentelic marble.
It stands on Ardittou street, in the neighbourhood of Mets, surrounded by modern buildings.











Archaeologists voice alarm over Artemis Agrotera temple in Athens
The Temple of Artemis Agrotera excavation site as it is today [Credit: artemisargotera.org]

In a press release titled “A monument in danger,” the Association of Greek Archaeologists says that despite numerous decisions published by the Central Archaeological Council since 1964 for the immediate expropriation of the land it stands on and the surrounding properties and the protection and promotion of the site, no action has ever been taken.
“The political responsibilities of successive political leaderships, are obvious,” the association says.











Archaeologists voice alarm over Artemis Agrotera temple in Athens
The temple was converted into a Christian basilica in the 5th century and much later in the 17th century with the addition
of a dome into the church dedicated to the Virgin Mary known as “Panagia stin Petra”. The detailed drawings
of elevations, ground plans and members of the temple and its pediment (now in the museum of Berlin
and Venice) executed by architects J. Stewart & N. Revett on their visit to Athens give testimony
of the monument as it stood in 1753 [Credit: WikiCommons]

“This unacceptable and disgraceful situation … that was created under pressure from private interests is not only endangering the archaeological site itself, but also violates the law,” it added.
Archaeologists said the site forms an archaeological unity with the neighbouring Temple of Olympian Zeus and authorities must therefore initiate expropriation procedures, complete the excavations and necessary studies and return it to the public as an open archaeological site.











Archaeologists voice alarm over Artemis Agrotera temple in Athens
Reconstruction of the Temple of Artemis Agrotera [Credit: Viajando la Vida/Flickr]

The temple was converted into an Early Christian church in the mid-5th century AD. the first excavations on the site were conducted in 1897 by the Archaeological Society of Athens.


Source: Kathimerini [September 14, 2018]



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Hubble Uncovers Never-Before-Seen Features Around a Neutron Star


NASA – Hubble Space Telescope patch.


Sept. 17, 2018


An unusual infrared light emission from a nearby neutron star detected by NASA’s Hubble Space Telescope could indicate new features never before seen. One possibility is that there is a dusty disk surrounding the neutron star; another is that there is an energetic wind coming off the object and slamming into gas in interstellar space the neutron star is plowing through.


Although neutron stars are generally studied in radio and high-energy emissions, such as X-rays, this study demonstrates that new and interesting information about neutron stars can also be gained by studying them in infrared light, say researchers.


The observation, by a team of researchers at Pennsylvania State University, University Park, Pennsylvania; Sabanci University, Istanbul, Turkey; and the University of Arizona, Tucson, Arizona, could help astronomers better understand the evolution of neutron stars — the incredibly dense remnants after a massive star explodes as a supernova. Neutron stars are also called pulsars because their very fast rotation (typically fractions of a second, in this case 11 seconds) causes time-variable emission from light-emitting regions.



Animation above: This animation depicts a neutron star (RX J0806.4-4123) with a disk of warm dust that produces an infrared signature as detected by NASA’s Hubble Space Telescope. The disk wasn’t directly photographed, but one way to explain the data is by hypothesizing a disk structure that could be 18 billion miles across. The disk would be made up of material falling back onto the neutron star after the supernova explosion that created the stellar remnant. Animation Credits: NASA, ESA, and N. Tr’Ehnl (Pennsylvania State University).


A paper describing the research and two possible explanations for the unusual finding appears Sept. 17, 2018, in the Astrophysical Journal.


“This particular neutron star belongs to a group of seven nearby X-ray pulsars — nicknamed ‘the Magnificent Seven’ — that are hotter than they ought to be considering their ages and available energy reservoir provided by the loss of rotation energy,” said Bettina Posselt, associate research professor of astronomy and astrophysics at Pennsylvania State and the lead author of the paper. “We observed an extended area of infrared emissions around this neutron star — named RX J0806.4-4123 — the total size of which translates into about 200 astronomical units (approximately 18 billion miles) at the assumed distance of the pulsar.”


This is the first neutron star in which an extended signal has been seen only in infrared light. The researchers suggest two possibilities that could explain the extended infrared signal seen by Hubble. The first is that there is a disk of material — possibly mostly dust — surrounding the pulsar.


“One theory is that there could be what is known as a ‘fallback disk’ of material that coalesced around the neutron star after the supernova,” said Posselt. “Such a disk would be composed of matter from the progenitor massive star. Its subsequent interaction with the neutron star could have heated the pulsar and slowed its rotation. If confirmed as a supernova fallback disk, this result could change our general understanding of neutron star evolution.”


The second possible explanation for the extended infrared emission from this neutron star is a “pulsar wind nebula.”



Image above: This is an illustration of a pulsar wind nebula produced by the interaction of the outflow particles from the neutron star with gaseous material in the interstellar medium that the neutron star is plowing through. Such an infrared-only pulsar wind nebula is unusual because it implies a rather low energy of the particles accelerated by the pulsar’s intense magnetic field. This hypothesized model would explain the unusual infrared signature of the neutron star as detected by NASA’s Hubble Space Telescope. Image Credits: NASA, ESA, and N. Tr’Ehnl (Pennsylvania State University).


“A pulsar wind nebula would require that the neutron star exhibits a pulsar wind,” said Posselt. “A pulsar wind can be produced when particles are accelerated in the electrical field that is produced by the fast rotation of a neutron star with a strong magnetic field. As the neutron star travels through the interstellar medium at greater than the speed of sound, a shock can form where the interstellar medium and the pulsar wind interact. The shocked particles would then emit synchrotron radiation, causing the extended infrared signal that we see. Typically, pulsar wind nebulae are seen in X-rays and an infrared-only pulsar wind nebula would be very unusual and exciting.”


Using NASA’s upcoming James Webb Space Telescope, astronomers will be able to further explore this newly opened discovery space in the infrared to better understand neutron star evolution.


In addition to Posselt, the research team included George Pavlov and Kevin Luhman at Pennsylvania State; Ünal Ertan and Sirin Çaliskan at Sabanci University; and Christina Williams at the University of Arizona. The research was supported by NASA, The Scientific and Technological Research Council of Turkey, the U.S. National Science Foundation, Pennsylvania State, the Penn State Eberly College of Science, and the Pennsylvania Space Grant Consortium.



Hubble Space Telescope (HST). Animation Credits: NASA/ESA

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.


Related links:


The science paper by B. Posselt et al.: http://imgsrc.hubblesite.org/hvi/uploads/science_paper/file_attachment/350/Posselt_2018_ApJ_865_1.pdf


NASA’s Hubble Portal: http://www.nasa.gov/hubble


Pennsylvania State University’s Release: http://science.psu.edu/news-and-events/2018-news/Posselt9-2018


Image (mentioned), Animations (mentioned), Text, Credits: NASA/Karl Hille/Space Telescope Science Institute/Ray Villard/Penn State Eberly College of Science, Office of Communications, University Park/Dr. Samuel J. Sholtis.


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Exercise and DNA Studies as Crew Checks Spacesuits


ISS – Expedition 56 Mission patch.


September 17, 2018


The Expedition 56 crew members started the work week exploring a variety of life science and ensuring the upkeep of advanced space research gear. U.S. spacesuits were also being looked at today ahead of a series of planned spacewalks.


All space station crew members exercise daily to maintain their health while living in space. Today, Flight Engineer Ricky Arnold strapped himself into an exercise bike and wore sensors to measure aerobic capacity, or how much physical exertion an astronaut can sustain in space. This helps doctors understand the fitness requirements necessary to successfully conduct spacewalks or respond to emergencies in the weightless environment of space.



Image above: Expedition 56 Commander Drew Feustel of NASA works inside the seven-windowed Cupola as the International Space Station was about to fly over the coast of Chile in South America. Image Credit: NASA.


Arnold then switched roles from subject to scientist as he extracted DNA from microbe samples swabbed from inside the International Space Station. The DNA undergoes further sample preparation and is sequenced using the Biomolecule Sequencer and Genes in Space hardware onboard the station. The research is helping scientists understand how life adapts to microgravity providing insights to improve crew health.


Commander Drew Feustel and Flight Engineer Serena Auñón-Chancellor, both from NASA, worked on a variety of science gear Monday. Auñón-Chancellor restocked the Human Research Facility-2 with medical supplies and Feustel reconfigured a rack in the Kibo laboratory module for the new Life Sciences Glovebox.



Image above: Flying over South Indian Ocean, near South Indonesia, seen by EarthCam on ISS, speed: 27’614 Km/h, altitude: 404,65 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam’s from ISS on September 17, 2018 at 23:16 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.


The duo then joined astronaut Alexander Gerst of ESA (European Space Agency) for spacesuit checks during the afternoon. The three astronauts verified the functionality of the suit jetpacks, ensured the correct sizing of the suits and cleaned the Quest airlock where U.S. spacewalks are staged. These suits will be used on a series of future spacewalks to upgrade batteries on the space station’s truss structure.


Related links:


Expedition 56: https://www.nasa.gov/mission_pages/station/expeditions/expedition56/index.html


Aerobic capacity: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=644


DNA microbe samples: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687


Biomolecule Sequencer: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1917


Human Research Facility-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=58


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


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


Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.


Best regards, Orbiter.chArchive link


500-year-old burials revealed in french city of Rouen during construction work

Human skeletons have been discovered in the heart of the northern french city of Rouen (Seine-Maritime), near the ruins of Saint-Sauveur Church, during work carried out to restore the town square, or Place du Vieux-Marché.











500-year-old burials revealed in french city of Rouen during construction work
Credit: ©SL/76actu

This is the third archaeological excavation currently underway after those of the Saint-Éloi Church – by the National Institute of Preventive Archaeological Research (Inrap) – and of the Saint-Gervais square.
This unexpected discovery arouses great interest among the archaeologists involved. At least two skeletons in very good condition are visible. The shape of a third is easily perceptible. Around it, several bones are also visible, still intermixed with stones and earth.











500-year-old burials revealed in french city of Rouen during construction work
Credit: ©SL/76actu

According to the archaeologists from Inrap, the skeletons found are those of former parishioners buried in the Saint-Sauveur cemetery between the 15th and 18th centuries.
“The remains of the bodies were found in a small area that had not been excavated during the construction of the underground car park and church in the early 1970s”, says Mark Guillon, an Inrap researcher. “At the time, we had found many skeletons, but we didn’t know if there were any other burials left.”











500-year-old burials revealed in french city of Rouen during construction work
Credit: ©SL/76actu

“Once the Revolution was over, between 1784 and 1792, the city slowly encroached on the Saint-Sauveur cemetery and the graves were covered with the paving stones,” continues Guillon.
The remains of about twenty women, men and children, have been exhumed to date. “We are only digging 30 centimetres from the surface, but we estimate that there are 2,000 graves under our feet, a couple of metres deep,” adds Guillon.


The current excavations are expected to last another a month.


Source: Actu [September 14, 2018]



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Bronze Age petroglyphs discovered in Siberia

More than 100 new rock paintings, some featuring mythical monsters, have been discovered at the Shalabolino rock art site on the Tuba river, southern Siberia, Alexander Zaika, chief of the Russian Geographical Society’s expedition, told TASS on Tuesday.











Bronze Age petroglyphs discovered in Siberia
One of the newly discovered petroglyphs [Credit: Sibnovosti]

The expedition has examined the entire three-kilometre massif around the site to discover about 300 flat surfaces with pieces of ochre rock paintings made with the use of knockout, engraving and wiping techniques. The newest finds include more than 30 such surfaces with over 100 Stone Age petroglyphs.
“Along animals, humans in boats, on skis and mounted on horses, scenes of hunting, war and rituals, the petroglyphs depict mythical predators, a kind of composite characters featuring traits of wolves, bears, panthers and wild boars. Such drawings are dated to a period around the second millennium B.C.,” Zaika said, adding that the newly-discovered rock drawings are preliminarily attributed to the Okunev culture, a Bronze Age culture in southern Siberia.











Bronze Age petroglyphs discovered in Siberia
Ancient rock drawings in Siberia [Credit: © Vladimir Baikalsky/TASS]

Among the paintings are anthropomorphic face masks with horns and fangs and other animal traits. He said that these masks could reflect the day-and-night, good-and-evil mythology of that period.


The Shalabolino rock art site, located 35 kilometers west of the town of Kuargino, takes its name from the nearby village of Sahalabolino. Drawings dating from the New Stone Age to the Early Middle Ages cover the right side of a steep rock on the bank of the Tuba river.


Source: TASS [September 14, 2018]



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Unique relief with gladiators found in Nicopolis ad Istrum, Bulgaria

A unique relief, depicting a gladiatorial battle, was discovered by the archaeologist Dr. Ivan Tsarov during excavations in the Roman city of Nicopolis ad Istrum in what is today central north Bulgaria.











Unique relief with gladiators found in Nicopolis ad Istrum, Bulgaria
The newly discovered gladiator fight relief from the Roman city of Nicopolis ad Istrum in North Bulgaria likely
dates back to the reign of the Severan Dynasty (193 – 235 AD) [Credit: Yantra Dnes Daily]

The relief is from the 2nd and 3rd century and was discovered under the pavement of the small square in the southwest corner of the forum complex.


The researchers hypothesize that it was either part of a frieze that decorated a trading table for measuring the weight of olive oil and grains, or that it was part of a sacrificial altar used for rituals before gladiator fights.


“It is interesting that this relief reveals the dynamics of the fight between two types of gladiators, the classical type (secutor) armed with a short sword, helmet, and shield, vs. the retiarius armed with a trident, a dagger, a net, and an arm and shoulder guard,” Tsaros says, as quoted by local daily Yantra Dnes.


The gladiator fights in Nicopolis ad Istrum are believed to have taken place in its amphitheatre whose location has not yet been established.


The only evidence that the residents of Nicopolis ad Istrum were entertained by gladiators have been three inscriptions mentioning gladiator fights. The most interesting of those was discovered back in 1985 in the Roman city’s gymnasium (gymnasion), a training facility for athletes competing in public games.


The study of the archaeological reserve began last week with excavations in the last unspoiled southwest part of the forum. In the 3rd century this was the site of a small town square that was later destroyed during a severe earthquake.


In the 5th-6th century the city administration was exported to the Tsarevets hill, while some of the locals remained in Nicopolis. They remove the collapsed columns, burying them in huge pits, and then levelled the area.


Source: Archaeology in Bulgaria [September 14, 2018]



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Thousands of objects discovered in Scandinavia’s first Viking city

If you want to know anything about the Viking Age, Ribe, in west Denmark, is the place to go.











Thousands of objects discovered in Scandinavia's first Viking city
The bead-makers of 8th century Ribe used pieces of glass gathered from old Roman mosaics as their raw material.
They didn’t have access to newly manufactured glass. This is one of the many details that tells
 us about the city’s network [Credit: Museum of Southwest Jutland]

Archaeologists from Aarhus University and Southwest Jutland Museums (Denmark) have been excavating the Viking city as part of the Northern Emporium Project in minute detail, reports ScienceNordic.


We have dug down to three metres, where we find traces of the first cities of the Nordic region.


Thousands of items discovered beneath the streets of Ribe


Deep beneath street level are thousands of Viking finds. We have discovered everything from beads, amulets, coins, and lost combs, to dog excrement and gnawed bones.


We have also been surprised on several occasions, such as when we discovered a piece of a lyre (a harp-like stringed instrument), complete with tuning pegs. This discovery alone gives the Viking trading city of Ribe a whole new soundtrack.


Another extraordinary find is the discovery of runic inscriptions.


“High-definition” archaeology reveals new information


Interesting as this is, we have been looking for something completely different. What makes Ribe special is that this is where a city emerged. The people who lived here weren’t primarily farmers for household purposes but were craftsmen, seafarers, tradesmen, innkeepers, and maybe even lyrists.











Thousands of objects discovered in Scandinavia's first Viking city
3D scans are used to document and analyse the many layers of flooring (yellow) and layers of soil (blue)
from the Viking age houses. In the cut out area loom weights and other larger object
can be seen in situ on the floors [Credit: Sarah Croix]

We have known about the existence of the early period of Ribe for many years but excavating the deep layers to study this early period is expensive and time-consuming. Earlier excavations have therefore focused on smaller areas. However, two years ago the Carlsberg Foundation joined the excavation with the funding that made it possible to start a new and bigger excavation.


Meanwhile new methods of archaeology, including 3-D laser surveying, DNA research, and soil chemistry, allow us to tease out new information from the site.


These ‘high-definition’ methods were developed by the Centre of Excellence for Urban Network Evolutions (UrbNet) funded by the Danish National Research Foundation.


How is a city established?


The early period of Ribe is a riddle: How was the city established in a part of the world where no one had ever lived in a city before? That is the question our excavation tried to answer.


Clues from earlier excavations were difficult to interpret, and scientists discussed whether Ribe was simply a seasonal market town for generations before people started to settle there more permanently.











Thousands of objects discovered in Scandinavia's first Viking city
This stone fireplace has been the centre of a house in the 800s. In the ground wall above the fireplace, floor layers
are seen from other houses, which later in the Viking Age had occupied the same space after the house
with the fireplace had been demolished [Credit: Southwest Jutland Museums]

One of the most important discoveries was that solid houses existed in Ribe only a few years after the earliest activities in the area, no later than the 720’s CE. This suggests a more or less resident population—that is a population of trade and craftsmanship in the area, an urban community of sorts.


The development of Ribe layer by layer


In the Ancient Middle East and Ancient Mediterranean the cities were placed near each other each with their own temples, palaces, markets and city walls. Each city was at the centre of the surrounding area. Yet early period Ribe and the next closest city were hundreds of kilometres apart.


On the other hand it’s evident that people visited the city from far away. It was a city that lived by its networks.


Networks of trade and information are crucial to city life throughout history. But it is a lot harder to observe networks in archaeological excavations than it is to dig up city walls and monuments. In this regard Ribe has an ace up its sleeve: the oldest layers of the city are untouched and this makes it possible to uncover the city’s history decade by decade. In doing so, we can see how the city’s networks developed.


Ribe contributed to the creation of the Viking Age


Ribe was an ideal departure point for sailing ships and it’s development depended on them., Around 700 CE, when Ribe was beginning to develop, maritime traffic at the North Sea was in its infancy. But by 800 CE, when the Viking Age is traditionally said to have begun, the sailing ship had its breakthrough in the North.











Thousands of objects discovered in Scandinavia's first Viking city
The remains of walls and floors from several buildings from the first half of the 700s
[Credit: Southwest Jutland Museums]

Commercial cities like Ribe with their extensive networks, were crucial in the sailing revolution, as the ships were used to trade the cities’ goods with the rest of Scandinavia. And in that regard, Ribe helped create the Viking Age as we know it.


In Ribe we see this change in the remains of workshops. These finds are the real scoop of the excavation. Time after time we get a close-up look at the earliest city-dwellers in the North and the crafts that made them special.


Networks of the craftsmen and the first globalisation


The craftsmen of Ribe depended on the city’s network both for access to raw materials and to sell their wares. We have found evidence of many trades: ironsmiths, amber workers, leather workers, comb makers, and jewellers, who worked with pewter, lead, copper alloys, silver and gold.


Initially, comb makers, who made intricately decorated combs and other tools from antlers, used local supplies such as antlers from stags. This changes around the beginning of the Viking Age, when they start using antlers from reindeer, which must have been imported from Norway.


The network of the bead makers changes just as drastically. In the oldest layers we find evidence of several smaller workshops, each only in use for days or maybe weeks. The raw material – colored fragments of glass – must have originated far from Ribe and it’s clear that each craftsman brought a slightly different range of colours.


The bead production continues for a couple of generations with the style of the bead changing according to the fashions of the day. However, the production stops around the emergence of the Viking Age. Instead, mass produced beads from the Middle East start arriving in bulk. The bead makers of Ribe are the first craftsmen in Denmark to be ousted by globalisation.


Scandinavia’s first city developed before global trade appeared


Ribe developed an impressive network in the Viking Age, but it was not yet global. This is indicated by several findings.











Thousands of objects discovered in Scandinavia's first Viking city
Wood and other organic materials are preserved in deep underneath the Viking city of Ribe. For example,
this piece of lyre with six tuning pegs, was found in a layer from the first half of the 8th century CE
[Credit: Museum of Southwest Jutland]

Analysis of the glass used by the bead makers shows that the glass originated in Palestine and Egypt. However, it was already several centuries old when it arrived in Ribe and so it must have been taken from old Roman mosaics, probably in Roman cities such as Cologne or Trier.


We also found a roman carnelian gemstone decorated with the picture of Venus, which had been forcibly removed from the gold ring it must have decorated.


Apparently, the gemstone was of no interest in Ribe. But the gold was. The raw material of the first goldsmiths in Ribe was very likely comprised of objects like these looted from Roman graves.


Other findings point in the same direction. A fragment of the ornately decorated Roman ceramic, terra sigillata, must have been picked up at a Roman ruin or grave and brought to Ribe as an amulet or souvenir. Even though these things originate far away they may have been brought from relatively nearby.


Findings show that the first city of the North appeared before trade with the Mediterranean and Middle East was established. It was another network that kick started the development of Ribe. The results of our excavation will no doubt tell us more about these origins in the coming years.


An epic expedition to the Viking Age


Wrapping up a big excavation like this is not the end. We have come home with bags full of samples, data, and discoveries that we have not yet had time to unpack and study properly. Many of the most important results are probably yet to come.


Now, we need to hit the laboratory, where we’ll spend hours and hours analysing samples to trace the activity in the city’s earliest houses. Terabytes of survey notes need processing and analyzing. And the network of the craftsmen needs to be mapped after analysing the materials and isotope studies.


The Northern Emporium-expedition to Viking age Ribe has gathered materials that will be used by scientists for many decades to come to answer age-old questions and hopefuly some new ones.











Thousands of objects discovered in Scandinavia's first Viking city
This gemstone is one of several Roman antiques that were hundreds of years old when they were lost in Ribe. It was
probably looted from a grave and removed from the gold ring it must have seated in. The stone is decorated
with a figure of Venus riding a dolphin [Credit: Southwest Jutland Museums]

Findings still need analysis


All in all, the project “Northern Emporium” has excavated about 100 square meters of cultural layers in the heart of the oldest Ribe.


It will set a new standard for archaeological research of cities through the development of field methods that include geochemical element analysis, micromorphology, and dynamic, electronic methods for documenting the excavation.


The project is sponsored by the Carlsberg Foundation. It is completed in close collaboration with the Centre of Excellence for Urban Network Evolutions (UrbNet) funded by the Danish National Research Foundation and the Museum of Southwest Jutland, which is responsible for the archaeology of Ribe.


The project will be continuing the analysis and publish the thousands of finds and observations in the coming years.


Author: Søren M. Sindbæk | Source: ScienceNordic [September 14, 2018]


This article was originally published on ScienceNordic. Read the original article.



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