суббота, 22 декабря 2018 г.

2018 December 22 A Cold December Night Image Credit &…

2018 December 22

A Cold December Night
Image Credit & Copyright: Petr Horálek

Explanation: They say Orion always comes up sideways, and he does seem to on this cold December night. The bright stars of the familiar northern winter constellation lie just above the snowy tree tops surrounding a cozy cottage near the town of Ustupky in the Czech Republic. But Gemini’s meteors also seem to rain on the wintry landscape. The meteor streaks are captured in exposures made near last Friday’s peak of the annual Geminid meteor shower. They stream away from the shower’s radiant above the trees, near the two bright stars of the zodiacal constellation of the Twins. Comet Wirtanen, a visitor to planet Earth’s skies, is visible too. Look for its telltale greenish coma near the stars of the seven sisters.

∞ Source: apod.nasa.gov/apod/ap181222.html

Archaeologist debunks the myth of ‘the nearly naked Bushmen’

It is said that “clothes maketh the man.” It is therefore a paradox that researchers have not shown more interest in the dress of the San hunter-gatherers, historically among the most studied groups of people in the world. Vibeke Maria Viestad, a senior lecturer at the Department of Archaeology, Conservation and History at the University of Oslo, believes this is so because of a prevailing myth about “the nearly naked bushman.”

Archaeologist debunks the myth of 'the nearly naked Bushmen'
Bushmen of South Africa, engraving, ca 1880 [Credit: Getty Images]

“The San people dressed differently from us, often with a bare upper body, and were therefore perceived as naked when first met by Europeans. This view was commonplace in travel descriptions and early research and also found its way into modern anthropology of the 1950s,” she says.

The early research on “the others—research often more racist than scientific—was often more concerned with the physiological differences between different peoples. Researchers measured the skull, rump and breast and were blind to the meaning of such cultural elements as clothes.

Extinct hunter gatherer culture

Viestad makes up for these scientific sins of omission in a new book where she endeavours to find an answer to what dress practices meant to the San people who lived as hunter gatherers in the area that is now the province of Northern Cape in South Africa.

The archaeologist has studied oral myths and folklore of the /Xam—the diagonal indicates a clicking sound – that were noted down in the 1870s. /Xam is one of the many different groups of San people, and this material provides a unique source for understanding an extinct language and a culture that is no longer practised.

The stories filled 138 notebooks when they were noted down and have since been digitalised. These are stories about everyday life and hunting, animals and plants, myths and folklores and—for someone who is interested in this specifically- a lot of information about dress and dress practices.

Because dressing the body was definitely part of /Xam culture.

“They used karosses, loincloths, different headgear, bags, leather shoes, tobacco pouches and jewellery; especially sought after was bead work from the shells of ostrich eggs. Dress was an essential part of both material and social culture,” says Viestad.

She uses a broad definition of the term “dress.” This covers both things worn on the body and things done to the body, such as tattoos, painting oneself, cutting patterns in the skin or applying scent. Like clothing, such “bodily modifications” were also an important part of the culture of the /Xam.

Generated social relationships between animals and people

Viestad’s research shows that clothes, jewellery, tattoos and the like had many of the same functions for the /Xam and other San peoples as it has for us. They marked identity and social belonging, were important for transition rituals, functioned as decorations and as a basis for widespread barter trade. Some were masters at making bags from turtle shells, others in the preparation of skin work.

Archaeologist debunks the myth of 'the nearly naked Bushmen'
Jewellery made of tail hair and glass beads [Credit: Iziko SA Museum of Cape Town/Nigel Pamplin]

“In addition to these easily recognisable functions, clothes also played a direct and essential role in creating and maintaining social relations,” says Viestad, who underlines that the /Xam people did not distinguish between people and other creatures in the same way we do.

“It gives meaning to say that they formed relationships with people, animals, water and other parts of nature,” she says.

Viestad describes a characteristic dichotomy in the /Xam people’s relations with animals: “On the one hand, it was the clothes that separated humans from animals. At the same time, they made their clothes from the animals and part of that animal identity remained in the clothes, so that a strong relationship arose between animal and human.

They also believed that if you did not show respect to animals and other creatures, you risked your clothes returning to their original nature. A garment of antelope leather could go back to being an antelope. They did not believe this in a literal sense, but more as an image of the world becoming chaotic if you did not maintain good relations with your surroundings.

Angry and soft rain

In the context of hunting rituals, medical rituals and rituals linked to rain and water, tattoos, cuts in the skin and the application of scent were the most important part of their dress.

“The purpose of such modifications of the body seems for the most part to have been protective, preventive or auspicious, but was also about these close relationships with nature, where other creatures were shown respect,” says Viestad.

She tells among other things that before the young /Xam girls could approach the water, they had to powder themselves with fragrant herbs, which they also had to sprinkle over the water.

“In this way, they created a bond between themselves and the water and showed respect. This was important so that they would get ‘soft rain,” making the earth fertile instead of ‘angry rain’ that just destroyed and washed the earth away.

Smeared themselves with sap from plants

Before the men could go hunting they would smear themselves with the sap of a particular root.

Archaeologist debunks the myth of 'the nearly naked Bushmen'
‘Animal bag’ from Gordonia in South Africa. Note how the legs of the ‘animal’ are tied together as a shoulder strap
[Credit: Iziko SA Museum of Cape Town/Nigel Pamplin]

“In this way, the hunter linked himself to the animal and showed it respect,” explains Viestad.

It is also believed that tattooing was a normal hunting ritual, where the men cut themselves and rubbed in charcoal made from the same root. When the cuts healed, the charcoal remained under the skin, something that could generate a stronger and more lasting relationship with the animals they were hunting.

Viestad explains that a similar custom is known from other groups of San people living in the Kalahari in the 1950’s and 60’s, but that they used charred meat from the last animal they had killed.

“Such customs might seem strange to us, but in their world these were part of important strategies for survival and for maintaining order in their existence,” says Viestad.

Created the moon from a leather shoe

She also highlights a myth that especially illustrates the close connection between animals, humans and other creatures in the world view of the /Xam people. The story goes that both the moon and the eland—the world’s largest antelope—were created from a leather shoe, such as the /Xam people used to make from eland leather.

“This story tells us that the shoe was once an eland and that the eland could become a shoe; that there was not a sharp distinction between the two,” explains Viestad.

When shamans or sorcerers used headgear made from springbok scalps in order for the springbok to follow them, we might presume that same type of logic.

“The springbok was the most important source for food and clothing and a person wearing a cap made from such springbok leather might under certain circumstances have had a perceived special relationship with this animal,” says the researcher.

Important for personal relationships

The /Xam people also strongly related to each other through their clothing. It was for example the men who made all the leather clothes and when they got married, they dressed the wives ‘into the marriage.”

Archaeologist debunks the myth of 'the nearly naked Bushmen'
Jewellery made from ostrich shells [Credit: Iziko SA Museum of Cape Town/Nigel Pamplin]

The men also made leather clothing for the children; in this way they gave something of themselves via the clothes.

“An inherited piece of jewellery would also be of sentimental value to me” explains the researcher, “but the /Xam people would probably have had a more direct approach to this: “The piece of jewellery I give to you contains a part of me.” And if the piece of jewellery was passed on to someone else, this person was also drawn into this relationship: into a chain of connections going right back to nature and to the material the piece of jewellery was made from.”

Two great collections

While working on the book, Viestad has also studied and compared two collections that document the clothes worn by different groups of San people in the early 1900s. The collections contained photographs, written documents, clothes, jewellery, bags and many other artefacts.

One of these was collected by Dorothea Bleek, who most probably had been asked to obtain artefacts for a museum exhibition while she was doing linguistic research among San people in the Northern Cape and later in the Kalahari. The at the time Medical Officer of South West Africa, Dr. Louis Fourie created an even more extensive collection containing more than 3,400 artefacts and 350 pictures.

“Bleek used a more traditional approach and emphasised that the clothes were associated with what role you held in the social structure, meaning gender, age, if one was married and so on. She was not especially interested in the differences between the different San people, while Fourie, who was more interested in the material culture as a starting point, could see great differences in the clothing between different groups,” explains Viestad.

Shows human diversity

With this book, Viestad helps to fill a gap in our knowledge of some of the otherwise most studied groups of peoples in the world in ethnographic and anthropological research.

Archaeologist debunks the myth of 'the nearly naked Bushmen'
Vibeke Maria Viestad’s book fills a gap in our knowledge of some of the most studied
peoples in anthropological history [Credit: Wits University Press]

For herself, she is mostly concerned that the book provides an example of an enormous human diversity.

“I feel it is important to explore other ways of thinking about the body, the world and social relationships. This might appear naive, but we need research that proves that there are and have been very different ways of understanding the world. Such knowledge can give us greater understanding of each other,” she says.

Archaeologist Vibeke Maria Viestad is also a participant in the research initiative Heritage Experience Initiative at the Faculty of Humanities, which will start in 2019.

Author: Øystein Rygg Haanæs | Source: University of Oslo [December 18, 2018]



Lucy Finds Its Place in the Solar System: Navigating NASA’s First Mission to the Trojan...

NASA – LUCY Mission patch.

Dec. 21, 2018

In science fiction, explorers can hop in futuristic spaceships and traverse half the galaxy in the blink of a plot hole. However, this sidelines the navigational acrobatics required in order to guarantee real-life mission success.

In 2021, the feat of navigation that is the Lucy mission will launch. To steer Lucy towards its targets doesn’t simply involve programming a map into a spacecraft and giving it gas money – it will fly by six asteroid targets, each in different orbits, over the course of 12 years.

Image above: This diagram illustrates Lucy’s orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary, giving the trajectory its pretzel-like shape. After launch in October 2021, Lucy has two close Earth flybys before encountering its Trojan targets. In the L4 cloud Lucy will fly by (3548) Eurybates (white), (15094) Polymele (pink), (11351) Leucus (red), and (21900) Orus (red) from 2027-2028. After diving past Earth again Lucy will visit the L5 cloud and encounter the (617) Patroclus-Menoetius binary (pink) in 2033. As a bonus, in 2025 on the way to the L4, Lucy flies by a small Main Belt asteroid, (52246) Donaldjohanson (white), named for the discoverer of the Lucy fossil. After flying by the Patroclus-Menoetius binary in 2033, Lucy will continue cycling between the two Trojan clouds every six years. Image Credits: Southwest Research Institute.

Lucy’s destination is among Jupiter’s Trojan asteroids, clusters of rocky bodies almost as old as the Sun itself, and visiting these asteroids may help unlock the secrets of the early solar system. Lucy will encounter a Main Belt asteroid in 2025, where it will conduct a practice run of its instruments before encountering the first four Trojan targets from 2027-2028. In 2033, Lucy will end its mission with a study of a binary system of two Trojans orbiting each other.

Getting the spacecraft where it needs to go is a massive challenge. The solar system is in constant motion, and gravitational forces will pull on Lucy at all times, especially from the targets it aims to visit. Previous missions have flown by and even orbited multiple targets, but none so many as will Lucy.

Scientists and engineers involved with trajectory design have the responsibility of figuring out that route, under Flight Dynamics Team Leader Kevin Berry of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. One such engineer is Jacob Englander, the optimization technical lead for the Lucy mission. “There are two ways to navigate a mission like Lucy,” he said. “You can either burn an enormous amount of propellant and zig-zag your way around trying to find more targets, or you can look for an opportunity where they just all happen to line up perfectly.” To visit these aligned targets, the majority of Lucy’s high-speed lane changes will come from gravity assists, with minimal use of fueled tweaks.

Though Lucy is programmed to throw itself out into a celestial alignment that will not occur for decades, it cannot be left to its own devices. Once the spacecraft begins to approach its asteroid targets, optical navigation is the next required step.

“OpNav,” as optical navigation technical lead Coralie Adam refers to it, is the usage of imagery from the on-board cameras to determine Lucy’s position relative to the target. This is a useful measurement used by the navigation team to tweak Lucy’s route and ensure it stays on the nominal flyby path. Adam works in Simi Valley, California, with KinetX, the company NASA selected to conduct Lucy’s deep space navigation.

Image above: Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit. Image Credit: NASA.

By using the communications link from the spacecraft to Earth, Adam said, the Lucy team gets information about the spacecraft’s location, direction and velocity. The spacecraft takes pictures and sends them down to Earth, where Adam and other optical navigators use software to determine where the picture was taken based on the location of stars and the target. The orbit determination team uses this data along with data from the communications link to solve for where the spacecraft is and where it is expected to be, relative to the Trojans. The team then designs a trajectory correction maneuver to get Lucy on track. “The first maneuver is tiny,” said navigation technical lead Dale Stanbridge, who is also of KinetX. “But the second one is at 898 meters per second. That’s a characteristic of Lucy: very large delta V maneuvers.” Delta V refers to the change in speed during the maneuver.

Communicating all of these navigation commands with Lucy is a process all on its own. “Lockheed Martin sends the commands to the spacecraft via the Deep Space Network,” Adam said. “What we do is we work with Lockheed and the Southwest Research Institute, where teams are sequencing the instruments and designing how the spacecraft is pointed, to make sure Lucy takes the pictures we want when we want them.”

“The maneuvers to correct Lucy’s trajectory are all going to be really critical because the spacecraft must encounter the Trojan at the intersection of the spacecraft and Trojan orbital planes,” Stanbridge said. “Changing the spacecraft orbital plane requires a lot of energy, so the maneuvers need to be executed at the optimal time to reach to next body while minimizing the fuel cost.”

While Lucy is conducting deep space maneuvers to correct its trajectory toward its targets, communications with the spacecraft are sometimes lost for brief periods. “Blackout periods can be up to 30 minutes for some of our bigger maneuvers,” Stanbridge said. “Other times you could lose communications would be when, for example, the Sun, comes between the Earth tracking station and the spacecraft, where the signal would be degraded by passing through the solar plasma.”

Losing contact isn’t disastrous, though. “We have high-fidelity predictions of the spacecraft trajectory which are easily good enough to resume tracking the spacecraft when the event causing a communication loss is over,” Stanbridge said.

What route will Lucy take once its mission is complete, nearly 15 years from now? “We’re just going to leave it out there,” Englander said. “We did an analysis to see if it passively hits anything, and looking far into the future, it doesn’t.” The Lucy team has given the spacecraft a clear path for thousands of years, long after Lucy has rewritten the textbooks on our solar system’s history.

The Lucy mission is led by Principal Investigator Dr. Hal Levison from Southwest Research Institute in Boulder, Colorado. NASA Goddard in Greenbelt, Maryland, manages the mission. Lockheed Martin Space in Denver will build the spacecraft and conduct mission operations.

For more information about NASA’s Lucy mission, visit:



Images (mentioned), Text, Credits: NASA/Bill Steigerwald/Goddard Space Flight Center, by Tamsyn Brann.

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Space Station Science Highlights: Week of December 17, 2018

ISS – Expedition 57 Mission patch / ISS – Expedition 58 Mission patch.

Dec. 21, 2018

After contributing to hundreds of experiments in biology, biotechnology, physical science and Earth science aboard the world-class orbiting laboratory, three members of the International Space Station’s Expedition 57 crew, including NASA astronaut Serena Auñón-Chancellor, returned to Earth Thursday, safely landing at 12:02 a.m. EST (11:02 a.m. local time) in Kazakhstan.

Image above: Expedition 57 crew members Alexander Gerst of ESA, Sergey Prokopyev of Roscosmos, and Serena Auñón-Chancellor of NASA sit inchairs outside the Soyuz MS-09 spacecraft after landing in a remote area near the town of Zhezkazgan, Kazakhstan. Image Credit: NASA.

The Expedition 57 crew Highlights included investigations into new cancer treatment methods and algae growth in space. The crew also installed a new Life Sciences Glovebox, a sealed work area for life science and technology investigations that can accommodate two astronauts.

Here’s a look at some of the science conducted this week aboard the orbiting lab:

Investigation studies dexterity in space

Microgravity provides a unique environment to study dexterous manipulation. The European Space Agency’s GRIP investigation studies long-duration spaceflight effects on the abilities of human subjects to regulate grip force and upper limb trajectories when manipulating objects using different kinds of movements (e.g. oscillatory movements, rapid discrete movements and tapping gestures), while restrained in the seated or supine position. This week, the crew performed the GRIP science tasks restrained to a chair in the supine, or lying facing upward, position.

Data collected from this investigation may provide insight into potential hazards for astronauts as they manipulate objects in different gravitational environments. It could also support design and control of haptic interfaces to be used in challenging environments, and provide information about motor control that potentially will be useful for the evaluation and rehabilitation of patients with neurological diseases on Earth.

Crew provides blood and saliva for immune study

Protecting crew health is important as NASA prepares for long duration, deep-space missions. Functional Immune studies previously uninvestigated areas of the body’s immune response, and if spaceflight alters a crew member’s susceptibility to disease.

Image above: ESA astronaut Alexander Gerst completes a blood collection with the help of NASA astronaut Serena Auñón-Chancellor. Image Credit: NASA.

The immune system is a complex weaving of biological structures and processes. Decreased activity in just one piece can cause changes in disease risk within the human body. Studies have shown that microgravity modifies the immune system. This may create an environment where rashes, unusual allergies and latent virus reactivation may present themselves in some crew members.

This week as a part of Functional Immune, the crew provided blood and saliva samples to be used to determine the changes taking place in crewmembers’ immune systems during flight.

Airway Monitoring

With dust particles present in the space station atmosphere, Airway Monitoring studies the occurrence and indicators of airway inflammation in crewmembers, using ultra-sensitive gas analyzers to evaluate exhaled air. This helps to highlight any health impacts and to maintain crewmember well-being on future human spaceflight missions. This is especially important on longer-duration missions – for example, to the Moon and Mars – where crewmembers will have to be more self-sufficient in identifying and avoiding such conditions. This kind of research may also benefit similar conditions, such as asthma, on Earth.

This week, the crew completed Low nitric oxide (NO) and High NO measurements for the ambient pressure session in the Destiny Laboratory.

Image above: David Saint-Jacques, of the Canadian Space Agency, completes the Bone Densitometer calibration in support of the Rodent Research-8 investigation. Image Credit: NASA.

Other work was performed on these investigations:

– The Spaceflight-induced Hypoxic/ROS Signaling (APEX-05) experiment grows different wild and mutant varieties of Arabidopsis thaliana, in order to understand how their genetic and molecular stress response systems work in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1775

– CASIS PCG 16 evaluates growth of LRRK2 protein crystals in microgravity. LRRK2 is implicated in Parkinson’s disease, but crystals of the protein grown on Earth are too small and compact to study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7855

– Rodent Research-8 (RR-8) examines the physiology of aging and the effect of age on disease progression using groups of young and old mice flown in space and kept on Earth: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7713

The Bone Densitometer uses X-rays to measure the bone mineral density (and the lean and fat tissue) of mice living aboard the station. As a result, researchers hope to develop medical technology that will combat bone density loss in space and on Earth, helping millions of senior citizens who suffer from osteoporosis: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1059

– Hydrogels are often used for tissue regeneration purposes due to their high water content and how easily they can be customized.  Hydrogel Formation and Drug Release in Microgravity Conditions takes advantage of reduced fluid motion in microgravity to more precisely study behavior of the gel and its potential as a wound-healing patch: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7749

Space to Ground: Holiday Homecoming: 12/21/2018

Related links:

Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

New cancer treatment methods: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7502

Algae growth in space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7446

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

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

Functional Immune: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2011

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

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 (mentioned), Video (NASA), Text, Credits: NASA/Michael Johnson/Vic Cooley, Lead Increment Scientist Expeditions 57/58.

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Successful launch of a Proton-M launch vehicle with a Russian spacecraft for the Ministry...


December 21, 2018

Proton-M carrying Blagovest No. 13L lift off

Today, December 21, the Proton-M space rocket with a spacecraft was launched from the Baikonur cosmodrome in the interests of the Russian Ministry of Defense.

All prelaunch operations, launch and flight of the Proton-M launch vehicle were carried out in the normal mode. The successful launch of the spacecraft into the target orbit was provided by the Briz-M upper stage.

The new satellite has been accepted for control by the ground-based means of the Air and Space Forces (VKS) of Russia.

Video above: Launch of the Proton-M launch vehicle with a Russian spacecraft for the Ministry of Defense. Video Credit: Roscosmos TV.

It was the 2nd in 2018 and the 418th launch in the history of the Proton launch vehicle, (including all its modifications).

The Proton carrier rocket and the Briz-M upper stage were developed and mass-produced by the Center named after M. V. Khrunichev. The Proton-M PH is an upgraded version of the heavy-duty Proton carrier rocket with improved operational and environmental performance. Thanks to the use of the Briz-M upper stage, the Proton-M rocket is capable of delivering a payload of more than 6 tons to a geotransition orbit. The first launch of the Proton-M booster with the upper stage Breeze-M took place on April 7, 2001 of the year. Since then, this modification of the Proton rocket has been used in the 104th space launches.

Blagovest No. 13L satellite

The Blagovest No. 13L communications satellite to cover Russian territory and provide high-speed Internet, television and radio broadcast, and voice and video conferencing services for Russian domestic and military users.

Roscosmos Press Release: https://www.roscosmos.ru/25882/

Images, Video (mentioned), Text, Credits: ROSCOSMOS/Günter Space Page/Orbiter.ch Aerospace/Roland Berga.

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Getting a glimpse inside the moon

New research from University of Alberta physicists provides the first-ever model of our Moon’s rotational dynamics, taking into consideration its solid inner core. Their model helps to explain why, as seen from Earth, the Moon appears to wobble on its axis.

Getting a glimpse inside the moon
U of A researchers have provided the first model of the moon’s rotational dynamics that accounts for the solid inner core.
The new model also helps explain why the moon appears to wobble on its axis as it orbits Earth
[Credits: NASA/JPL/USGS]

The answer, said physicist Mathieu Dumberry, lies in the complex geometry of the Moon’s orbit, locked in what is known as a Cassini state.
“The Moon goes around the Earth, but its orbit is inclined by about five degrees with respect to the normal to the ecliptic plane, the plane about which Earth rotates around the Sun. But just like the Earth’s rotation axis is inclined by 23.5 degrees in space, the Moon’s rotation axis is also inclined, by about 1.5 degrees,” explained Dumberry, associate professor in the Department of Physics. “Over one orbit, it points at the same direction in space — which is in the same plane as the normal to the orbit of the moon. This defines a Cassini state.”

This type of lunar orbit was first observed by Giovanni Cassini more than four centuries ago. Since that time, the complex mathematical and physical elements of the Cassini state have been examined by scientists around the world. But what makes this model unique is accounting for a solid inner core at the centre of the Moon.

The heart of the matter

“Essentially, we took all forces into account and tried to predict the angle of the inner core of the Moon,” explained Dumberry. “The tilt angle can be predicted, but we need to know accurately the deep interior structure on the Moon. However we know it is not aligned with the mantle or the fluid core. We determined that the inner core is tilted as much as 17 degrees away from the mantle in one direction or 33 degrees away in the other.”

And, if scientists can identify the angle of the inner core, they will be able to develop a more accurate picture of the interior of the Moon.

“This is the first model of the rotational dynamics of the Moon that fully takes into account the presence of a solid inner core,” said Christopher Stys, graduate student who conducted this research under the supervision of Dumberry. “Understanding the composition of the Moon’s interior may provide insight to the events leading up to the formation of the Moon and the early history of the Earth.”

The findings are published in the Journal of Geophysical Research: Planets.

Author: Katie Willis | Source: University of Alberta [December 19, 2018]



Planetary astronomers identify cycle of spectacular disturbances at Jupiter’s...

A regular pattern of unusual meteorological events at Jupiter’s equator has been identified by planetary scientists at the University of Leicester.

Planetary astronomers identify cycle of spectacular disturbances at Jupiter's equator
Scientists at the University of Leicester and NASA’s Jet Propulsion Laboratory predict next parting
of Jupiter’s veil of clouds for 2019 [Credit: NASA]

Jupiter’s striped appearance of light zones and dark brown belts provides breathtaking views through amateur and professional telescopes alike. But Jupiter’s stripes can change and shift over poorly-understood timescales, sometimes expanding and contracting, sometimes fading away entirely.

Using a large database of observations of Jupiter spanning more than four decades, scientists have been working to understand the forces shaping these gargantuan weather changes on the Solar System’s largest planet.

In research recently published in Geophysical Research Letters, the team used data – telescopic infrared observations – to show evidence of unique events at Jupiter’s equator when the usual thick, white clouds appeared to be completely missing.

Lead author Dr Arrate Antuñano from the University of Leicester’s Department of Physics and Astronomy said: “Jupiter’s equator is normally completely clouded over, appearing dark in the infrared because those clouds appear in silhouette against Jupiter’s warm internal glow. Those thick clouds make the equator look white through a visible telescope.”

Co-author Dr Leigh Fletcher also from the University of Leicester’s Department of Physics and Astronomy said: “Professional astronomers have been tracking Jupiter’s infrared emission for decades, particularly using NASA’s Infrared Telescope Facility on top of Maunakea, Hawai’i.

“Only by putting all of these observations together, from a wide variety of instruments over more than three Jupiter years – a year on Jupiter lasts 12 Earth years – did we begin to spot a pattern.”

Planetary astronomers identify cycle of spectacular disturbances at Jupiter's equator
The clearing of Jupiter’s clouds during the last equatorial disturbance event in 2007. Left: 5 μm image of Jupiter captured
on 3 March 2007 with the NSFCam2 instrument mounted at the Infrared Telescope Facility (IRTF) inHawai’i, showing
the unusual cloud-clearing at the equator. Right: 5 μm image captured on 3 January 2016 with the SpeX instrument
also mounted at the IRTF during an undisturbed period [Credit: University of Leicester]

Dr Antuñano said: “Every six or seven years, we found examples of observations when the equatorial clouds had vanished completely, allowing us to see deeper into Jupiter’s churning atmosphere. These cloud-clearing disturbances left the equator looking very bright in the infrared, and dark brownish in visible light. These disturbances lasted for 12-18 months, and we saw spectacular examples in 1973, 1979, 1992, 1999 and 2006.”

With this pattern, the researchers expected to see events in 1985 and 2013, but although the brownish equatorial colours were apparent, the clouds didn’t clear completely.

Dr Glenn Orton, a Senior Research Scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California, and one of the people responsible for the enormous database of ground-based Jupiter observations used in this study, explained: “As usual, Jupiter is reluctant to give up all its secrets at once. It seems that this six-seven-year pattern isn’t perfect, and sometimes we don’t see a complete cloud-clearing disturbance.”

None of these previous equatorial disturbances have been properly analysed by a visiting spacecraft.

Dr Antuñano said: “If we follow the pattern over the last 45 years, the really exciting result of this work is that we expect to see a new event very soon, perhaps as early as next year.”

Jupiter is currently close to solar conjunction, meaning that it’s hiding away behind the Sun, and won’t become visible to Earth-based observers for the next few months. There are already tantalising hints that things are changing, with small breaks in Jupiter’s equatorial clouds apparent in the latest images.

Planetary astronomers identify cycle of spectacular disturbances at Jupiter's equator
The clearing of Jupiter’s clouds during the last equatorial disturbance event in 2007. Left: Colour (RGB)image of Jupiter
captured by Anthony Wesley (Australia) from 2 March 2007. Right: Colour (RGB) image captured by Tiziano Olivetti
 (Thailand) from 2 January 2016 [Credit: University of Leicester]

The new study, funded by the European Research Council and NASA, could have some surprising implications for Juno’s exploration of Jupiter. Juno has been orbiting Jupiter since July 2016, returning spectacular new insights into its deep atmosphere and magnetosphere.

Dr Orton said: “Peering beneath the clouds, Juno’s microwave instrument revealed a deep column of ammonia gas rising at the equator and condensing to form those white clouds at the equator. We’re excited to see whether that deep ammonia plume is about to change during the new equatorial disturbance event.”

Indeed, the scientists suspect that the accumulation of ammonia at the equator might help to explain the bizarre six-seven year pattern of the events.

Dr Antuñano added: “These long-term observations are the key to unlocking the secrets of these slow weather patterns and climate variations on Jupiter, and allow us to place the findings of NASA’s Juno mission into the proper historical context.”

Source: University of Leicester [December 19, 2018]



Newly discovered adolescent star seen undergoing ‘growth spurt’

Astronomers have discovered a young star undergoing a rare growth spurt — giving a fascinating glimpse into the development of these distant stellar objects.

Newly discovered adolescent star seen undergoing 'growth spurt'
This illustration shows a young star undergoing a type of growth spurt. Left panel: Material from the dusty and gas-rich
 disk (orange) plus hot gas (blue) mildly flows onto the star, creating a hot spot. Middle panel: The outburst begins – the
 inner disk is heated, more material flows to the star, and the disk creeps inward. Right panel: The outburst is in full
throttle, with the inner disk merging into the star and gas flowing outward (green)
[Credit: Caltech/T. Pyle (IPAC)]

A team of international researchers, including experts from the University of Exeter’s Physics and Astronomy department, have observed a rare stellar outburst on a newfound star, called Gaia 17bpi.

Gaia 17bpi belongs to a group of stars known as FU Ori’s, named after the original member of the group, FU Orionis found in the Orion constellation.

Typically these FU Ori stars, which are less than a few million years old, are hidden behind thick clouds of dust and are therefore hard to observe.

However, the research team spotted the star undertaking a dramatic phase of evolution, whereby matter swirling around falls onto the star, and so bulking up its mass. The team was able to see this stellar outburst through both infrared and visible light.

Gaia 17bpi is only the 25th member of the FU Ori class found to date, and one of only about a dozen caught in the act of an outburst.

Professor Tim Naylor, from Exeter’s Astrophysics group and co-author of the study said: “It’s taken a lot of patient waiting and careful sifting of data to uncover this star, but once we realised what was going it has exceeded expectations.

“It also gives us insight into events which may have happened as the planets in our own Solar System were beginning to form from a disc of material around the sun.”

Gaia 17bpi was first spotted by the European Space Agency’s Gaia satellite, which scans the sky continuously and makes precise measurements of stars in visible light. When Gaia spots a change in a star’s brightness, an alert goes out to the astronomy community.

Exeter graduate student , and co-author of the study Sam Morrell was the first to notice that the star had brightened. Fellow members of the research team took the discovery forward, and discovered that the star’s brightening had been independently captured in infrared light by NASA’s asteroid-hunting NEOWISE satellite at the same time that Gaia saw it, as well as one-and-a-half-years earlier.

NASA’s infrared-sensing Spitzer Space Telescope also happened to have witnessed the beginning of the star’s brightening phase twice back in 2014, giving the researchers a bonanza of infrared data.

Newly discovered adolescent star seen undergoing 'growth spurt'
The location of Gaia 17bpi, which lies in the Sagitta constellation, is indicated in this image taken
by NASA’s Spitzer Space Telescope [Credit: NASA/JPL-Caltech/M. Kuhn (Caltech)]

“These FU Ori events are extremely important in our current understanding of the process of star formation but have remained almost mythical because they have been so difficult to observe,” says Lynne Hillenbrand, professor of astronomy at Caltech and lead author of a new report. “This is actually the first time we’ve ever seen one of these events as it happens in both optical and infrared light, and these data have let us map the movement of material through the disk and onto the star.”

The new findings shine light on some of the longstanding mysteries surrounding the evolution of young stars, including how a star acquires all of its mass. Theorists believe that FU Ori events — in which mass is dumped from the disk onto the star over a total period of about 100 years — may help solve the riddle.

The new study shows, with the most detail yet, how material moves from the midrange of a disk, in a region located around one astronomical unit — the distance between the Earth and the sun — from the star, to the star itself.

NEOWISE and Spitzer were the first to pick up signs of the buildup of material in the middle of the disk. As the material started to accumulate in the disk, it warmed up, giving off infrared light. Then, as this material fell onto the star, it heated up even more, giving off visible light, which is what Gaia detected.

“While NEOWISE’s primary mission is detecting nearby solar system objects, it also images all of the background stars and galaxies as it sweeps around the sky every six months,” says co-author Roc Cutri, lead scientist for the NEOWISE Data Center at IPAC, an astronomy and data center at Caltech. “NEOWISE has been surveying in this way for five years now, so it is very effective for detecting changes in the brightness of objects.”

Carlos Contreras, a Postdoctoral Research Fellow from the University of Exeter and co-author of the study added: “The FU Ori-type outbursts could also have an impact on the early formation and evolution of the planets that form in the discs around young stars.

The discovery of Gaia 17bpi was the by-product of an Exeter programme that has been monitoring a large sample of young stars using the data from the Gaia satellite, to measure the frequency of the FU Ori events during the planet forming stage.”

The researchers used the W. M. Keck Observatory and Caltech’s Palomar Observatory to help confirm the FU Ori nature of the newfound star. Says Hillenbrand, “You can think of Gaia as discovering the initial crime scene, while Keck and Palomar pointed us to the smoking gun.”

The research is published in The Astrophysical Journal.

Source: University of Exeter [December 19, 2018]



Rare Celtic gold coin found in Slovenia

Archaeologists, doing a protective excavation in Bela Krajina without any major expectations, were most surprised when they hit an extremely rare find – a bronze belt bearing a golden coin from the 3rd century BC.

Rare Celtic gold coin found in Slovenia

Rare Celtic gold coin found in Slovenia
Celtic gold stater featuring head of Alexander the Great (obverse) and the goddess Athena Nike (reverse)
[Credit: ZRCalnik]

According to expert Peter Kos, the coin found at the Pezdirčeva Njiva site is a Celtic imitation of an Alexander the Great stater featuring goddesses Athena Nike.
“A golden coin as such is a rare find in Slovenia. As far as I know, this is the third golden coin found at Slovenian sites, and as it seems, the oldest,” Lucija Grahek of the Archaeology Institute of the Academy of Sciences and Arts told the STA.

The find is even more valuable because coins usually turn up in searches with metal detectors or in searches in riverbeds, while this one provides archaeologists with much more data.

Rare Celtic gold coin found in Slovenia

Rare Celtic gold coin found in Slovenia

Rare Celtic gold coin found in Slovenia

Rare Celtic gold coin found in Slovenia

Rare Celtic gold coin found in Slovenia
View of the excavation site at Pezdirčeva Njiva and some of the recovered artefacts
[Credit: ZRCalnik]

It was found in “a closed grave, it’s position on the belt is clear, and even more, some organic material has been preserved on the belt”, potentially making it possible to carbon date the find.

“This will further increase [the find’s] value and contribute to the progress of Slovenian and European science,” Grahek added.

Archaeologists found the coin and the belt in a series of 15 graves they dug out at Pezdirčeva Njiva in Podzemelj. Most of them date from the 4th century BC, while finds such as ceramics and iron weapons indicate that some date from the 3rd century BC.

Source: Total Slovenia News [December 19, 2018]



Skeleton from Mesolithic period discovered in Malaysian cave

Researchers stumbled upon a discovery of historic value – the skeleton of a teenage girl believed to be from the Mesolithic period – while excavating Gua Chawan in the Malaysian state of Kelantan.

Skeleton from Mesolithic period discovered in Malaysian cave
Department of National Heritage senior museum assistant Khairil Amri Abd Ghani examining
the skeleton found in Gua Chawan, Kelantan [Credit: Bernama]

The team from Universiti Kebangsaan Malaysia, along with officers from the archaeology department at the National Heritage Department, estimated the remains to be around 6,000 to 8,000 years old.

Tourism, Arts and Culture Minister Datuk Mohammadin Ketapi said the discovery was crucial in helping to understand ancient funerary rites and culture of prehistoric society, as well as the presence of early man in Malaysia.

“We believe this skeleton to be a teenage girl based on the pelvic bone.

Mohammadin said the skeleton, which was found on Nov 2 in the Nenggiri Valley in Ulu Kelantan, was removed from Gua Chawan on Nov 10, and placed at a laboratory.

The Heritage Department will take 60 days to conduct conservation works at the site for record and restoration purposes.

Teeth and shell samples will be sent to the Beta Lab in the United States for chronometric dating.

“The Heritage Department will be collecting all the artefacts for historical reference and the public will be able to view them as soon as conservation works have been completed,” Mohammadin said.

Source: The Star Online [December 19, 2018]



Hellenistic theatre of Smyrna under excavation

An ancient theatre in what was formerly the Greek city of Smyrna (Turkish İzmir), built during the Hellenistic period, is currently being excavated by a team from Dokuz Eylül University (DEU).

Hellenistic theatre of Smyrna under excavation
Credit: AA

The excavations have reportedly unearthed sections of the cavea (ie. the semi-circular bank of seating) resting on the slopes of Mount Pagos (Kadifekale today).

Speaking to state-run Anadolu Agency, the head of the excavations, Akın Ersoy, who is also an associate professor of archaeology, said Smyrna had a history of 8,000 years and the latest chain of the history was on the slopes between the Agora and Mount Pagos.

He said the construction of the theatre, perched on a rocky hill with a magnificent view of the city, had started in 3rd century BC and was used for some 700 years, when it was abandoned in the 4th century.

“We started excavations in 2012. Theatre excavations are troublesome because both filling levels are too high and a significant amount of blocks were used in the construction of this monumental structure. We have reached the rows of seats during excavations after 1,500 years. Some of the walls had already been reached during the clearing of houses. Next year we hope that we will reach the orchestra pit, which is one of the most important parts of theatre structures.”

Hellenistic theatre of Smyrna under excavation

Hellenistic theatre of Smyrna under excavation

Hellenistic theatre of Smyrna under excavation

Hellenistic theatre of Smyrna under excavation

Hellenistic theatre of Smyrna under excavation

Hellenistic theatre of Smyrna under excavation
Credit: YeniAsir

Ersoy said they also found ancient sculptures, coins and ceramics during the excavation works.

“In the ancient period, ancient cities competed against each other. We are facing a contestant theatre of a competitive city. Perhaps we will witness many new things with this theatre. The next phase will be to make this place registered as an ancient site,” Ersoy said.

The most comprehensive information about the ancient theatre can be obtained from the plans, drawings and studies of Austrian architects and archaeologists Otto Berg and Otto Walter, who conducted research in the region in 1917 and 1918. According to their reports, the remains of the theatre carry the characteristics of the Roman era.

Editor’s Note

Smyrna, founded around the 11th century BC by Aeolian settlers, was one of the principal Greek settlements in western Anatolia, with a continuous Greek presence until September 13, 1922, when the Turkish army of Kemal Atatürk burned the city’s Greek and Armenian neighbourhoods in what became known as the Great Fire of Smyrna. The death toll from the ensuing massacre of the indigenous Greek and Armenian populations is believed to have numbered up to 100,000 people.

Source: Hurriyet Daily News [December 19, 2018]



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Iron Hills Northerly Prehistoric Stone Circle, 15.12.18.The freezing weather conditions...

Iron Hills Northerly Prehistoric Stone Circle, 15.12.18.

The freezing weather conditions just added to the atmosphere of this site; a shame that someone had partially destroyed the stone wall that bisects the circle.

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https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...