суббота, 16 марта 2019 г.

United Launch Alliance Successfully Launches WGS-10 Mission

ULA –  Delta IV / WGS-10 Mission poster.

March 16, 2019

Delta IV WGS-10 launch

A United Launch Alliance (ULA) Delta IV rocket carrying the tenth Wideband Global SATCOM (WGS) satellite for the U.S. Air Force lifted off from Space Launch Complex-37 on March 15 at 8:26 p.m. EDT. ULA has been the exclusive launch provider for all ten WGS satellites.

“We are very proud to deliver this critical asset to orbit in support of the U.S. and Allied warfighters deployed around the world defending our national security,” said Gary Wentz, ULA vice president of Government and Commercial Programs. “Thank you to the entire ULA team and mission partners for their outstanding teamwork and dedication to mission success.”

Delta IV launches WGS-10

The WGS-10 satellite, built by the Boeing Company, is an important element of the new high-capacity satellite communications system. Each WGS satellite provides more wideband communications capacity than the entire Defense Satellite Communications System.

WGS satellite

This mission launched aboard a Delta IV Medium+ (5,4) configuration vehicle, built in Decatur, Alabama, including a 5-meter Payload Fairing and standing at 218 feet. The common booster core for Delta IV was powered by the RS-68A engine, and the Delta Cryogenic Second Stage was powered by the RL10B-2 engine, both supplied by Aerojet Rocketdyne. Northrop Grumman provided the four solid rocket motors. At liftoff, the main engine and four solid rocket motors comined to produce approximately 1.7 million pounds of thrust.

To date ULA has a track record of 100 percent mission success with 133 successful launches.

United Launch Alliance (ULA): https://www.ulalaunch.com/

Images, Video, Text, Credits: ULA/Günter Space Page/SciNews.

Greetings, Orbiter.chArchive link

Let’s try a formal heuristic approach

I created a massive outgroup f3-statistics matrix, featuring almost 300 ancient and present-day populations and individuals, for the purpose of running unsupervised, or at least semi-supervised, fine scale mixture tests with nMonte. Most of the stats were computed with 400-900K SNPs, which is a lot and should provide plenty of power. The matrix is available in a zip file here.
The results I’m getting with this new setup are very similar to those obtained with the Global25. The main differences, as far as I can see for now, are that the f3 data produce more stable results when modeling very deep ancestry, while the Global25 provides more accuracy when modeling fine scale recent ancestry (probably because it’s better at picking up more recent genetic drift).
Let’s investigate some pertinent issues with the new data using nMonte and PAST. How about we start with these?

– where did Bell Beakers get their steppe ancestry from?
– which Steppe_MLBA group did Indians get their steppe ancestry from?
– do the present-day Irish have any Hallstatt ancestry?
– what is the origin of present-day Basques?
– what is the precise ancestry of Armenia_ChL?
– do the Swat Iron Age samples really lack BMAC ancestry?
– does Anatolia_MLBA really lack steppe ancestry?

Please note that I’m still in the process of incorporating the ancients from the new Olalde et al. paper on the genomic history of Iberia (see here) into the f3 matrix. However, I’ve already updated the Global25 datasheets with most of these samples.

Global 25 datasheet (scaled)
Global 25 pop averages (scaled)
Global 25 datasheet
Global 25 pop averages

By the way, Hajji_Firuz_ChL I2327, from Narasimhan et al. 2018, is now labeled Hajji_Firuz_IA in the above datasheets, because my understanding is that he’s actually from the Iron Age rather than the Chalcolithic period. For background reading about this controversial sample see here and here. I don’t have any more info on this topic; we’ll just have to wait for the formal publication of the Narasimhan et al. manuscript to get all the details. Apparently it’s coming very soon.
See also…
An exceptional burial indeed, but not that of an Indo-European
Maykop: a multi-ethnic layer cake?
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…


Symptom Hunting Brain disorders caused by bacterial infections…

Symptom Hunting

Brain disorders caused by bacterial infections are difficult to diagnose because the symptoms can be easily misattributed to other conditions. To help us better diagnose these infections in future, a team of scientists went on the hunt for signs of how these infections affect brain cells. A few days after a group of mice developed one such infection, the team found that several layers of the hippocampus, a small structure nestled deep inside the middle of brain, had changed. One layer of a certain type of brain cell (in blue, left half of this image) had reduced in density and their connections (green) showed signs of damage, while the density of these same cells in the layer above (right half) had increased. This small but important clue will help us piece together the puzzle of how bacterial infections affect the brain at a neuronal level and lead to brain disorders.

Written by Gaëlle Coullon

You can also follow BPoD on Instagram, Twitter and Facebook

Archive link

Preparing for two very different personal exhibitions about prehistory around the UK...

Preparing for two very different personal exhibitions about prehistory around the UK later this year. Getting a bit excited. More details soon!

Source link

Malachite Pseudomorph after Azurite | #Geology #GeologyPage…

Malachite Pseudomorph after Azurite | #Geology #GeologyPage #Mineral

Locality: Tsumeb Mine, Tsumeb, Oshikoto Region (Otjikoto Region), Namibia

Dimensions: 22.0 × 13.5 × 6.5 cm

Photo Copyright © Crystal Classics

Geology Page



Quartz var Agate | #Geology #GeologyPage #Mineral Locality:…

Quartz var Agate | #Geology #GeologyPage #Mineral

Locality: Schlottwitz, Germany.

Dimensions: 6.0 × 5.4 × 0.5 cm

Photo Copyright © Crystal Classics

Geology Page



Amazing Landscape Agate | #Geology #GeologyPage #Agate…

Amazing Landscape Agate | #Geology #GeologyPage #Agate #Mineral

Geology Page



2019 March 16 NGC 3324 in Carina Image Credit & Copyright:…

2019 March 16

NGC 3324 in Carina
Image Credit & Copyright: Martin Pugh

Explanation: This bright cosmic cloud was sculpted by stellar winds and radiation from the hot young stars of open cluster NGC 3324. With dust clouds in silhouette against its glowing atomic gas, the pocket-shaped star-forming region actually spans about 35 light-years. It lies some 7,500 light-years away toward the nebula rich southern constellation Carina. A composite of narrowband image data, the telescopic view captures the characteristic emission from ionized sulfur, hydrogen, and oxygen atoms mapped to red, green, and blue hues in the popular Hubble Palette. For some, the celestial landscape of bright ridges of emission bordered by cool, obscuring dust along the right side create a recognizable face in profile. The region’s popular name is the Gabriela Mistral Nebula for the Nobel Prize winning Chilean poet.

∞ Source: apod.nasa.gov/apod/ap190316.html

SDSS J1430+1339: Storm Rages in Cosmic Teacup

SDSS 1430+1339

Credit X-ray: NASA/CXC/Univ. of Cambridge/G. Lansbury et al; 

Optical: NASA/STScI/W. Keel et al.

Fancy a cup of cosmic tea? This one isn’t as calming as the ones on Earth. In a galaxy hosting a structure nicknamed the “Teacup,” a galactic storm is raging.

The source of the cosmic squall is a supermassive black hole buried at the center of the galaxy, officially known as SDSS 1430+1339. As matter in the central regions of the galaxy is pulled toward the black hole, it is energized by the strong gravity and magnetic fields near the black hole. The infalling material produces more radiation than all the stars in the host galaxy. This kind of actively growing black hole is known as a quasar.

Located about 1.1 billion light years from Earth, the Teacup’s host galaxy was originally discovered in visible light images by citizen scientists in 2007 as part of the Galaxy Zoo project, using data from the Sloan Digital Sky Survey. Since then, professional astronomers using space-based telescopes have gathered clues about the history of this galaxy with an eye toward forecasting how stormy it will be in the future. This new composite image contains X-ray data from Chandra (blue) along with an optical view from NASA’s Hubble Space Telescope (red and green). 

The “handle” of the Teacup is a ring of optical and X-ray light surrounding a giant bubble. This handle-shaped feature, which is located about 30,000 light-years from the supermassive black hole, was likely formed by one or more eruptions powered by the black hole. Radio emission — shown in a separate composite image with the optical data — also outlines this bubble, and a bubble about the same size on the other side of the black hole. 

Previously, optical telescope observations showed that atoms in the handle of the Teacup were ionized, that is, these particles became charged when some of their electrons were stripped off, presumably by the quasar’s strong radiation in the past. The amount of radiation required to ionize the atoms was compared with that inferred from optical observations of the quasar. This comparison suggested that the quasar’s radiation production had diminished by a factor of somewhere between 50 and 600 over the last 40,000 to 100,000 years. This inferred sharp decline led researchers to conclude that the quasar in the Teacup was fading or dying.

New data from Chandra and ESA’s XMM-Newton mission are giving astronomers an improved understanding of the history of this galactic storm. The X-ray spectra (that is, the amount of X-rays over a range of energies) show that the quasar is heavily obscured by gas. This implies that the quasar is producing much more ionizing radiation than indicated by the estimates based on the optical data alone, and that rumors of the quasar’s death may have been exaggerated. Instead the quasar has dimmed by only a factor of 25 or less over the past 100,000 years.

The Chandra data also show evidence for hotter gas within the bubble, which may imply that a wind of material is blowing away from the black hole. Such a wind, which was driven by radiation from the quasar, may have created the bubbles found in the Teacup.

Astronomers have previously observed bubbles of various sizes in elliptical galaxies, galaxy groups and galaxy clusters that were generated by narrow jets containing particles traveling near the speed of light, that shoot away from the supermassive black holes. The energy of the jets dominates the power output of these black holes, rather than radiation.

In these jet-driven systems, astronomers have found that the power required to generate the bubbles is proportional to their X-ray brightness. Surprisingly, the radiation-driven Teacup quasar follows this pattern. This suggests radiation-dominated quasar systems and their jet-dominated cousins can have similar effects on their galactic surroundings.

A study describing these results was published in the March 20, 2018 issue of The Astrophysical Journal Letters and is available online. The authors are George Lansbury from the University of Cambridge in Cambridge, UK; Miranda E. Jarvis from the Max-Planck Institut für Astrophysik in Garching, Germany; Chris M. Harrison from the European Southern Observatory in Garching, Germany; David M. Alexander from Durham University in Durham, UK; Agnese Del Moro from the Max-Planck-Institut für Extraterrestrische Physik in Garching, Germany; Alastair Edge from Durham University in Durham, UK; James R. Mullaney from The University of Sheffield in Sheffield, UK and Alasdair Thomson from the University of Manchester, Manchester, UK.

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

Fast Facts for SDSS J1430+1339:

Scale: Image is about 16 arcsec (85,000 light years) across
Category: Quasars & Active Galaxies, Normal Galaxies & Starburst Galaxies
Coordinates (J2000): RA 14h 30m 29s | Dec +13° 39´ 11.79″
Constellation: Boötes
Observation Date: April 19, 2016
Observation Time: 13 hours 26 minutes
Obs. ID: 18149
Instrument: ACIS
References: Lansbury, G. et al. 2018. ApJ Letters, 856, 1; arXiv:1803.00009
Color Code: X-ray: Blue; Optical: Red, Green
Distance Estimate: About 1.1 billion light years

Archive link

Farmer discovers large Byzantine-era pithos in central Turkey

A farmer ploughing his field in Turkey’s central Niğde province discovered a large pithos believed to be dating back to the Byzantine period, reports said Monday.

Farmer discovers large Byzantine-era pithos in central Turkey
Credit: IHA

The unidentified farmer in Niğde’s Altunhisar district came across what he thought was a rock as he was ploughing the field near Kınık neighbourhood.

He got out of his tractor and started digging around the rock and found the pithos.

The farmer immediately informed authorities at Niğde Museum Directorate and the Provincial Cultural and Tourism Directorate regarding the discovery, who sent archaeologists to the farm, reports said.

Experts unearthed the ancient pithos and put it under the protection of the museum.

Source: Daily Sabah [March 12, 2019]



Researchers confirm massive hyper-runaway star ejected from the Milky Way Disk

A fast-moving star may have been ejected from the Milky Way’s stellar disk by a cluster of young stars, according to researchers from the University of Michigan who say the star did not originate from the middle of the galaxy, as previously believed by astronomers.

Researchers confirm massive hyper-runaway star ejected from the Milky Way Disk
Using one of the Magellan Telescopes in Chile as well as the data from the European Space Agency (ESA) space mission
Gaia, scientist recreated the trajectory of a massive “hyper-runaway star.” The trajectory shows the star was
ejected from the Milky Way disk, not the Galactic center as previously believed [Credit: Kohei Hattori]

“This discovery dramatically changes our view on the origin of fast-moving stars,” said Monica Valluri, a research professor in the Department of Astronomy at U-M’s College of Literature, Science, and the Arts. “The fact that the trajectory of this massive fast-moving star originates in the disk rather that at the Galactic center indicates that the very extreme environments needed to eject fast-moving stars can arise in places other than around supermassive black holes.”

Producing a fast-moving star requires lots of energy, usually found in extreme environments, Valluri said.

The Milky Way contains tens of billions of stars, most of which are distributed in a pizza-like structure called the stellar disk. In 2005, astronomers first discovered fast-moving stars that move more than twice as fast as most other stars—more than 1 million miles per hour, or 500 kilometers per second (310 miles/second), compared to the rest of the galaxy where stars average a bit more than 200 km/sec (124 miles/second).

Less than 30 of these extremely fast-moving stars (generally called “hypervelocity stars”) have been discovered so far.

When binary stars—a pair of stars that orbit around each other while moving through a galaxy—pass too close to a black hole, it captures one of the binary stars, and the other one is flung out in a “gravitational slingshot.” In order to produce the kinds of velocities astronomers measure for hypervelocity stars, the black hole has to be very massive.

Because there’s evidence that there is a supermassive hole at the center of the Milky Way, many astronomers believe that the majority of hypervelocity stars were ejected by this supermassive black hole.

Valluri and U-M postdoctoral researcher Kohei Hattori were interested in tracing the trajectory of LAMOST-HVS1, a massive fast-moving star that’s closer to the Sun than any other hypervelocity stars, to pinpoint where in the Milky Way it was ejected. They used one of the Magellan telescopes in Chile to determine the distance and velocity of the star.

Hattori then joined a group of international scientists who congregated in New York last year to participate in a hackathon to download, share and analyze data from the European Space Agency space mission Gaia, a space astrometry mission to make the largest, most precise three-dimensional map of the Milky Way.

Using the current location and current velocity of the star derived from Gaia and Magellan, the astronomers were able to trace back its path, or orbit. To their surprise, it appears the star was ejected from the stellar disk, and not from the center of the Milky Way.

“We thought this star came from the Galactic center. But if you look at its trajectory, it is clear that is not related to the Galactic center, Hattori said. “We have to consider other possibilities for the origin of the star.”

The authors theorize that the ejection of this massive star from the stellar disk may be the result of the star experiencing a close encounter with multiple massive stars or an intermediate mass black hole in a star cluster.

Although massive runaway stars that have been ejected from star clusters with speeds of 40-100 km/s (25-62 miles/second) have been known for a long time, none have been observed with the extreme ejection velocity as needed to explain LAMOST-HVS1. Theoretical models for runaway stars that include multiple-massive stars also very rarely produce such extreme velocities, suggesting a more exotic possibility—an intermediate mass black hole.

The computed path of the star originates at a location in the Norma spiral arm that is not associated with previously known massive star clusters. However if this hypothetical star cluster exists, it may be hidden behind the dust in the stellar disk. If it is found, it would provide the first opportunity to directly discover an intermediate mass black hole in the stellar disk of the Milky Way.

Also, the fact that this star may be ejected from a massive cluster in the stellar disk hints at the possibility that many other fast-moving stars may also have been ejected from such star clusters, the researchers say.

Both the Milky Way and Large Magellanic Cloud (a separate small galaxy, orbiting the Milky Way) are known to have some massive star clusters that might be important ejectors of fast-moving stars, contrary to the widely accepted view that they were ejected by interactions with the central black holes in one of these galaxies.

This would also lead to new insights into the interactions of stars and the possible formation of intermediate mass black holes in star clusters, the researchers say.

Their findings are published in the current issue of Astrophysical Journal.

Source: University of Michigan [March 13, 2019]



Understanding and controlling the molecule that made the universe

Trihydrogen, or H3+, is acknowledged by scientists as the molecule that made the universe. In recent issues of Nature Communications and the Journal of Chemical Physics, Michigan State University researchers employed high-speed lasers to shine a spotlight on the mechanisms that are key in H3+ creation and its unusual chemistry.

Understanding and controlling the molecule that made the universe
Marcos Dantus, University Distinguished Professor in chemistry and physics,
has recreated interstellar ions with lasers [Credit: MSU]

H3+ is prevalent in the universe, the Milky Way, gas giants and the Earth’s ionosphere. It’s also being created and studied in the lab of Marcos Dantus, University Distinguished Professor in chemistry and physics. Using ultrafast lasers – and technology invented by Dantus – a team of scientists is beginning to understand the chemistry of this iconic molecule.

“Observing how roaming H2 molecules evolve to H3+ is nothing short of astounding,” Dantus said. “We first documented this process using methanol; now we’ve been able to expand and duplicate this process in a number of molecules and identified a number of new pathways.”

Astrochemists see the big picture, observing H3+ and defining it through an interstellar perspective. It’s created so fast – in less time than it takes a bullet to cross an atom – that it is extremely difficult to figure out how three chemical bonds are broken and three new ones are formed in such a short timescale.

That’s when chemists using femtosecond lasers come into play. Rather than study the stars using a telescope, Dantus’ team literally looks at the small picture. The entire procedure is viewed at the molecular level and is measured in femtoseconds – 1 millionth of 1 billionth of a second. The process the team views takes between 100 and 240 femtoseconds. Dantus knows this because the clock starts when he fires the first laser pulse. The laser pulse then “sees” what’s happening.

The two-laser technique revealed the hydrogen transfer, as well as the hydrogen-roaming chemistry, that’s responsible for H3+ formation. Roaming mechanisms briefly generate a neutral molecule (H2) that stays in the vicinity and extracts a third hydrogen molecule to form H3+. And it turns out there’s more than one way it can happen. In one experiment involving ethanol, the team revealed six potential pathways, confirming four of them.

Since laser pulses are comparable to sound waves, Dantus’ team discovered a “tune” that enhances H3+ formation and one that discourages formation. When converting these “shaped” pulses to a slide whistle, successful formation happens when the note starts flats, rises slightly and finishes with a downward, deeper dive. The song is music to the ears of chemists who can envision many potential applications for this breakthrough.

“These chemical reactions are the building blocks of life in the universe,” Dantus said. “The prevalence of roaming hydrogen molecules in high-energy chemical reactions involving organic molecules and organic ions is relevant not only for materials irradiated with lasers, but also materials and tissues irradiated with x-rays, high energy electrons, positrons and more.”

This study reveals chemistry that is relevant in terms of the universe’s formation of water and organic molecules. The secrets it could unlock, from astrochemical to medical, are endless, he added.

Source: Michigan State University [March 13, 2019]



ALMA observes the formation sites of solar-system-like planets

Researchers have spotted the formation sites of planets around a young star resembling our Sun. Two rings of dust around the star, at distances comparable to the asteroid belt and the orbit of Neptune in our Solar System, suggest that we are witnessing the formation of a planetary system similar to our own.

ALMA observes the formation sites of solar-system-like planets
Artist’s impression of the disk around a young star DM Tau
[Credit: NAOJ]

The Solar System is thought to have formed from a cloud of cosmic gas and dust 4.6 billion years ago. By studying young planetary systems forming around other stars, astronomers hope to learn more about our own origins.
Tomoyuki Kudo, an astronomer at the National Astronomical Observatory of Japan (NAOJ), and his team observed the young star DM Tau using the Atacama Large Millimeter/submillimeter Array (ALMA). Located 470 light-years away in the constellation Taurus, DM Tau is about half the mass of the Sun and estimated to be three to five million years old.

“Previous observations inferred two different models for the disk around DM Tau,” said Kudo. “Some studies suggested the radius of the ring is about where the Solar System’s asteroid belt would be. Other observations put the size out where Neptune would be. Our ALMA observations provided a clear answer: both are right. DM Tau has two rings, one at each location.”

ALMA observes the formation sites of solar-system-like planets
You can see two concentric rings where planets may be forming
[Credit: ALMA (ESO/NAOJ/NRAO), Kudo et al. 2019]

The researchers found a bright patch in the outer ring. This indicates a local concentration of dust, which would be a possible formation site for a planet like Uranus or Neptune.
“We are also interested in seeing the details in the inner region of the disk, because the Earth formed in such an area around the young Sun,” commented Jun Hashimoto, a researcher at the Astrobiology Center, Japan. “The distribution of dust in the inner ring around DM Tau will provide crucial information to understand the origin of planets like Earth.”

The findings are published in The Astrophysical Journal.

Source: National Institutes of Natural Sciences [March 13, 2019]



The James Webb Space Telescope: Art + Science Continuing to Inspire


The James Webb Space Telescope – our next infrared space observatory – will not only change what we know, but also how we think about the night sky and our place in the cosmos. This epic mission to travel back in time to look back at the first stars and galaxies has inspired artists from around the world to create art inspired by the mission.


Image Credit: Anri Demchenko

It’s been exactly two years since the opening of the first James Webb Space Telescope Art + Science exhibit at the NASA Goddard Visitor Center.  The exhibit was full of pieces created by artists who had the special opportunity to visit Goddard and view the telescope in person in late 2016


Online Submission Image Credit: Tina Sarmaga

Since the success of the event and exhibit, the Webb project has asked its followers to share any art they have created that was inspired by the mission. They have received over 125 submissions and counting!  


Image Credit: Enrico Novelli


Online Submission Image Credit: Unni Isaksen

A selection of these submissions will be on display at NASA Goddard’s Visitor Center from now until at least the end of April 2019. The artists represented in this exhibit come not just from around the country, but from around the world, showing how art and science together can bring a love of space down to Earth.


More information about each piece in the exhibit can be found in our web gallery. Want to participate and share your own art? Tag your original art, inspired by the James Webb Space Telescope, on Twitter or Instagram with #JWSTArt, or email us through our website! For more info and rules, see: http://nasa.gov/jwstart.


Webb is the work of hands and minds from across the planet. We’re leading this international project with our partners from the European Space Agency (ESA) and the Canadian Space Agency (CSA), and we’re all looking forward to its launch in 2021. Once in space, Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

Learn more about the James Webb Space Telescope HERE, or follow the mission on Facebook, Twitter and Instagram.

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

What the world’s oldest eggs reveal about dinosaur evolution

A study of the world’s earliest known dinosaur eggs reveals new information about the evolution of dinosaur reproduction.

What the world's oldest eggs reveal about dinosaur evolution
Illustration of Massospondylus eggs and young dinosaurs
[Credit: Julius Csotonyi]

An international team of researchers led by Robert Reisz of the Department of Biology at the University of Toronto Mississauga studied the fossilized remains of eggs and eggshells discovered at sites in Argentina, China and South Africa—widely separated regions of the supercontinent Pangea.

At 195 million years old, they are the earliest known eggs in the fossil record, and they were all laid by a group of stem sauropods—long-necked herbivores that ranged in size from four to eight metres in length and were the most common and widely spread dinosaurs of their time.

Reisz is puzzled by the fact that “reptile and mammal precursors appear as skeletons in the fossil record starting 316 million years ago, yet we know nothing of their eggs and eggshells until 120 million years later. It’s a great mystery that eggs suddenly show up at this point, but not earlier.”

According to Koen Stein, a post-doctoral researcher at Universiteit Gent and lead author of the project, the eggs represent a significant step in the evolution of dinosaur reproduction. Spherical, and about the size of a goose egg, these dinosaur eggshells were paper-thin and brittle, much thinner than similar-sized eggs of living birds.”We know that these early eggs had hard shells because during fossilization they cracked and broke, but the shell pieces retained their original curvature.”

What the world's oldest eggs reveal about dinosaur evolution
Complete embryo of the Early Jurassic (190-million-year-old) dinosaur Massospondylus
discovered in the South African nesting site [Credit: Robert Reisz]

Members of the team, including Edina Prondvai and Jean-Marc Baele, analyzed shell thickness, membrane, mineral content and distribution of pores, looking for clues about why these early eggs might have developed hard shells.

The results of the study show that hard-shelled eggs evolved early in dinosaur evolution with thickening occurring independently in several groups, but a few million years later other reptiles also developed hard-shelled eggs.

One possibility is that hard and eventually thicker shells may have evolved to shield fetal dinosaurs and other reptiles from predators. “The hard shells would protect the embryos from invertebrates that could burrow into the buried egg nests and destroy them,” says Reisz.

Reisz adds that the study raises interesting questions for future investigation. “For example, we would like to understand why dinosaurs and their avian descendants never developed viviparity (live birth) and continued to rely on egg laying, while non dinosaurian reptiles and mammals, including ancient aquatic reptiles succeeded in evolving this more advanced reproductive strategy.”

The study is published in the journal Scientific Reports.

Source: University of Toronto Mississauga [March 14, 2019]



Researchers uncover new clues to surviving extinction

Scientists are peeking into ancient oceans to unravel the complexities of mass extinctions, past and future. A new examination of Earth’s largest extinction by scientists at the California Academy of Sciences and the University of Wisconsin-Milwaukee sheds light on how ecosystems are changed by such transformative events.

Researchers uncover new clues to surviving extinction
Scientists are peeking into ancient oceans to unravel the complexities of mass extinctions, past and future. A team of
researchers examined fossils of ocean-dwelling invertebrate creatures like clams, snails, corals, and sponges from Utah,
Nevada, and Texas. This region once comprised the shallow outskirts of the ancient and vast Panthalassa Ocean.
Using numerical methods, the team grouped marine survivor species into functional groups with similar traits,
like mobile bottom-dwelling omnivores such as sea urchins, to better understand the ecological
transformation in the wake of the Great Dying [Credit: © 2019 Ashley Dineen]

The study, published today in Biology Letters, suggests that the extinction survivors shared many of the same ecological roles as their predecessors, with one catch–there was a surge in the number of individuals with modern traits like greater mobility, higher metabolism, and more diverse feeding habits.

These hardy stand-outs did a better job of driving recovery, making ecological interactions more intense in the process: fish were more agile, diverse predators and marine invertebrates like mussels became more defensive. Insights into this system and its occupants can help guide modern conservation in identifying Earth’s most resilient and best equipped species in the face of environmental stress.

“We’re interested in understanding why certain species and communities survived and recovered better than others,” says Dr. Ashley Dineen, a former Academy postdoctoral researcher and current Museum Scientist of Invertebrate Paleontology at the UC Museum of Paleontology at Berkeley. “For a long time biology has focused on the number of species that survive extinction events, but we need to also ask what those species did and how they reacted to stresses–these insights are important as we push our planet into an increasingly uncertain future.”

The massive extinction event, often referred to as the “Great Dying,” took place 252 million years ago and frequently serves as a proxy for the modern era. Similar to today, the climate regime was transitioning from a cooler period to a warmer period. This climatic fluctuation, driven by massive volcanic eruptions that spewed noxious gases, increased the temperature and acidity of the oceans, decreased oxygen concentrations, interrupted mighty ocean currents, and turned the ocean system on its head.

Researchers uncover new clues to surviving extinction
A view of a fossilized sea lily (called Holocrinus) from one of the research sites exploring
the ancient and vast Panthalassa Ocean [Credit: © 2019 Ashley Dineen]

The researchers examined fossils of ocean-dwelling invertebrate creatures like clams, snails, corals, and sponges from Utah, Nevada, and Texas. This region once comprised the shallow outskirts of the ancient and vast Panthalassa Ocean. Using numerical methods, the team grouped marine survivor species into functional groups with similar traits, like mobile bottom-dwelling omnivores such as sea urchins, to better understand the ecological transformation in the wake of the Great Dying.

“We learned from our analysis that beyond documenting the number of species that arise during an ecological recovery, we need to know what they were actually doing–what scientists call their functional diversity,” says Dr. Peter Roopnarine, Academy Curator of Geology. “This helps us understand if the system has shifted toward favoring species with a variety of responses to stress.”

One surprising revelation: the study results showed significant ecological continuity among species–where species that were wiped out during the extinction event shared the same traits as those that originated in its aftermath. During recovery, however, there was a significant shift in numbers toward bigger and more active survivors that are strikingly similar to the inhabitants of our modern oceans. This shift in functional emphasis may be the the hallmark of an ecosystem set on the road to recovery.

“Our next step is to determine what kinds of species you want on the frontlines of recovery,” says Dineen. “For example, if you have a reef with twenty different species of corals but they all react the same to stressors, then they will all be similarly impacted when hit with a disturbance. But on a separate reef, if you have twenty coral species and each reacts differently to stress, the chance of losing the entire reef is lower. Having diverse coping mechanisms is critical for a future marked by increasing environmental stressors.”

The study team hopes their findings about species survivors will help scientists identify our modern–and urgently needed–conservation priorities.

“We’re often focused on estimating the number of species in an ecosystem, but we should also be learning about how–and how well–these species survive, and concentrate conservation efforts accordingly,” says Dineen. “When you consider the mass extinction we face today, it’s clear we have to take entire systems into account before it’s too late to correct course.”

Source: California Academy of Sciences [March 14, 2019]



Sea otters’ tool use leaves behind distinctive archaeological evidence

An international team of researchers has analyzed the use by sea otters of large, shoreline rocks as “anvils” to break open shells, as well as the resulting shell middens. The researchers used ecological and archaeological approaches to identify patterns that are characteristic of sea otter use of such locations. By looking at evidence of past anvil stone use, scientists could better understand sea otter habitat use.

Sea otters' tool use leaves behind distinctive archaeological evidence
Wild sea otter at Bennett Slough Culverts opening mussels using emergent anvil stone 
[Credit: Monterey Bay Aquarium, Jessica Fujii. Haslam et al. 2019]

Sea otters are an especially captivating marine mammal, well known for their use of rocks to break open shells. Sea otters are estimated to have once numbered between 150,000-300,000 individuals and their range stretched from Baja California, Mexico, around the northern Pacific Rim to Japan. Their numbers were dramatically reduced by the fur trade. In California, the southern sea otter population was reduced to around 50 individuals, but a massive conservation effort has resulted in increasing their numbers to around 3000 today. However, the southern sea otter is still considered threatened.
Sea otters are unique for being the only marine mammal to use stone tools. They often use rocks to crack open shells while floating on their back, and also sometimes use stationary rocks along the shoreline as “anvils” to crack open mollusks, particularly mussels. A joint project including the Max Planck Institute for the Science of Human History, the Monterey Bay Aquarium and the University of California, Santa Cruz, among others, has resulted in a first-of-its-kind interdisciplinary study published in Scientific Reports, combining ten years of observations of sea otters with archaeological methods to analyze sea otter use of such anvil stones, also known as emergent anvils.

Sea otter use of anvil stones leaves distinctive wear and shell middens that are characteristic of sea otters

Researchers spent ten years between 2007-2017 observing sea otters consuming mussels at the Bennett Slough Culverts site in California. Their analysis identified that mussels were the most common prey eaten at the site and were the only prey for which the sea otters used stationary anvil stones. The sea otters used such stones for about 20% of the mussels they consumed.

Sea otter pounding a mussel on an emergent anvil, above water, at Bennett Slough Culverts 

[Credit: Natalie Uomini, Haslam et al. 2019]

Interestingly, careful analysis of the stationary anvil stones using archaeological methods showed that their use resulted in a recognizable damage pattern that was distinguishable from what would be caused by human use. For example, the sea otters preferentially struck the mussels against points and ridges on the rocks, and struck the rocks from a position in the water, rather than from the land or from on top of the rock.

Consistent damage pattern on broken mussel shells indicates probable “pawedness” in sea otters

In addition to the stones themselves, the researchers also carefully analyzed the mussel shells left around the stationary anvils. The researchers took a random sample of the shell fragments from these shell middens, which likely contained as many as 132,000 individual mussel shells. They found an extremely consistent damage pattern, with the two sides of the mussel shell still attached, but a diagonal fracture running through the right side of the shell.

“The shell breakage patterns provide a novel way to distinguish mussels broken by sea otter pounding on emergent anvils from those broken by humans or other animals,” explains Natalie Uomini of the Max Planck Institute for the Science of Human History. “For archaeologists who excavate past human behaviour, it is crucial to be able to distinguish the evidence of sea otter food consumption from that of humans.”

Sea otters' tool use leaves behind distinctive archaeological evidence
Mussel shell breakage patterns at the Bennett Slough Culverts site. (A) Outer and (B) inner faces of each valve; (C) drawing
 of the exterior of a mussel shell showing the typical sea otter breakage pattern (illustration by Neil Smith); (D) broken
mussel shells in situ [Credit: Image (C): Neil Smith; Images (A), (B), & (D): Michael Haslam. Haslam et al. 2019]

In combination with analysis of videos they took of the otters using the anvils, researchers could see that the otters held the shells evenly in both paws, but when striking the shell against the anvil tended to have their right paw slightly on top. Though the total number of otters observed was small, these results suggest that otters may exhibit handedness, or “pawedness,” as do humans and many other mammals.

Potential for archaeological investigations of past sea otter behaviour

The researchers hope that the study will be useful for archaeologists working with coastal populations, as a way to distinguish between human and sea otter use of rocks and consumption of marine resources. Additionally, the research could be helpful in future studies of the geographic spread of stationary anvil use throughout the former sea otter range, and how far into the past this behaviour extends.

“Our study suggests that stationary anvil use can be detected in locations previously inhabited by sea otters. This information could help to document past sea otter presence and diet in locations where they are currently extirpated,” explains Jessica Fujii of the Monterey Bay Aquarium.

“More broadly,” she adds, “the recovery of past animal behavioural traces helps us to understand the evolution of behaviours like stone anvil use, which is rare in the animal kingdom and is extremely rare in marine animals. We hope that this study establishes a new path for the growing field of animal archaeology.”

Source: Max Planck Institute for the Science of Human History [March 14, 2019]



700-year-old well-preserved lacquer coffin discovered in Jiangsu

A rare, well-preserved lacquer coffin dating back to the Yuan Dynasty (1206-1368) has been unearthed in east China’s Jiangsu Province, local authorities said Thursday.

700-year-old well-preserved lacquer coffin discovered in Jiangsu
Credit: Sohu.com

Changzhou Museum said a tomb group was recently found at a construction site in Tangling Village in the city of Changzhou, where a coffin, looking like a freshly-painted one, was unearthed.
“We speculated that the good condition of the coffin might be attributed to the sticky mud between the chamber and coffin, which could isolate the air. While the high underground water level also helped isolate the air and keep the color of the coffin bright,” said Peng Hui, director of the archaeological office of the museum.

However, there was a lot of liquid inside the 700-year-old coffin due to its poor water resistance. To discharge the liquid from the coffin and minimize the impact on things inside the coffin, archaeologists spent around 16 hours discharging 500 litres of liquid from the coffin, Peng said.

700-year-old well-preserved lacquer coffin discovered in Jiangsu

700-year-old well-preserved lacquer coffin discovered in Jiangsu
Credit: Sohu.com

700-year-old well-preserved lacquer coffin discovered in Jiangsu

700-year-old well-preserved lacquer coffin discovered in Jiangsu
Credit: Sohu.com

So far, five wooden combs and two bamboo fine-toothed combs and bronze cash coins have been found.
Changzhou has a long history of comb manufacturing, tracing back to the Wei-Jin period (220-420).

“Yuan Dynasty tombs were seldom discovered in the southern lower reaches of the Yangtze River. The findings are very important for the study of Changzhou’s history,” said Huang Jiankang, deputy curator of the museum.

Source: Xinhua News Agency [March 14, 2019]



Rare inscription in Greek uncovered in archaeological excavations in the Negev

A 1700-year old stone bearing a Greek inscription referring to the name of the city of Elusa (Hebrew: Halutza) has been discovered in archaeological excavations in Halutza National Park in the Negev. The excavations in the ancient city of Elusa are part of a project directed by Prof. Michael Heinzelmann on behalf of the University of Cologne in cooperation with Dr. Tali Erickson-Gini on behalf of the Israel Antiquities Authority​. Students from the University of Cologne and the University of Bonn participated in three years of excavations, which are underwritten by the German-Israeli Foundation for Scientific Research and Development.

Rare inscription in Greek uncovered in archaeological excavations in the Negev
Student from the University of Cologne excavating the bathhouse furnace and hypocaust
discovered this month in Elusa [Credit: Dr. Tali Erickson-Gini, IAA]

The inscription is being studied by Prof. Leah Di Segni from the Hebrew University of Jerusalem. The discovery of an inscription with the name of the ancient city in the site itself is a rare occurrence. The name of the city of Elusa appears in a number of historical documents and contexts, including the Madaba mosaic map, the Nessana papyri and other historical references. However, this is the first time that the name of the city has been discovered in the site itself. The inscription mentions several Caesars of the tetrarchy which allow to date it around 300 CE.
In addition, in the recent excavation season, a bathhouse and Byzantine church were uncovered. The 40 m long three-aisled church contained an eastward apse, whose vault was originally decorated with a glass mosaic. Its nave was decorated with marble. The bathhouse is a large, urban complex of which were revealed part of the furnace and caldarium (hot room). The well-preserved hypocaust underlying the caldarium heated the floor and walls by way of brick-built channels and ceramic pipes. Its originates in the Middle Roman period but was in use until the 6th c. CE.

Rare inscription in Greek uncovered in archaeological excavations in the Negev
The Greek inscription bearing the name Elusa 
[Credit: Dr. Tali Erickson-Gini, IAA]

Elusa was founded towards the end of the 4th century BCE as an important station along the Incense Road, the ancient road between Petra and Gaza. The city continued to develop, reaching its peak in the Byzantine period in the fourth to mid-sixth centuries CE. In that period, it was inhabited by thousands of inhabitants and was the only city in the Negev.
The three-year project, underwritten by the Germany-Israeli Foundation for Scientific Research and Development, included a combination of pedestrian surveys and technological methods such as geophysical surveys and remote imaging in order to map the ancient city and its surroundings. During the project, researchers succeeded in reconstructing the plan of the city and identifying its streets which often were accompanied by porticoes and blocks of buildings, all of which display elements of both western and eastern planning and construction. The surveys have also revealed the presence of nine churches, a huge peristyle building, maybe a market building, and the existence of at least three pottery workshops. The city covered in its heyday a surface of c. 450 dunams reaching a population of c. 8.000 inhabitants.

In wake of the wide-ranging surveys carried out by the German expedition, excavations were carried out at key points in the site to reveal the development of the city. According to Dr. Tali Erickson-Gini, a project member on behalf of the Israel Antiquities Authority: “The export of high-quality wine from the Negev Highlands in the Byzantine period was responsible for economic prosperity that affected the entire region.
Elusa was also an important station on the route used by Christian pilgrims on their way to and from Santa Katarina in southern Sinai and as such was visited by many foreign travelers. The site appears to have gone out of existence by the end of the seventh century CE, but its name was preserved locally in the Arabic name of its ruins: ‘el-Khalassa’. The site was used as a source of building stone for Ottoman Gaza and Beer Sheba until the British Mandate period and as a result few building remains can be seen on the surface today and much of the site is hidden under the sand.”

Source: Israel Ministry of Foreign Affairs [March 14, 2019]



Artificial intelligence for the study of sites

An experimental study led by researcher Abel Moclán, from the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), has just been published in the Archaeological and Anthropological Sciences journal, which proposes a new method to understand how the faunal assemblages were generated in archaeological sites, and how they could have interacted with groups of humans and carnivores in the places they occupied.

Artificial intelligence for the study of sites
Three examples of the different types of notches
[Credit: A. Moclán]

This new method involves the use of artificial intelligence and machine learning algorithms to decipher whether faunal assemblages were generated by hominids or carnivores, specifically hyenas and/or wolves. “Thanks to this method, we can discern among the acting agents with a certainty of over 95%,” says Abel Moclán.

To carry out this study, bone fractures have been analyzed in order to interpret whether they were fractured by human groups to consume the bone marrow, or if, on the contrary, the carnivores fractured the bones when trying to access this same resource.

This method can be used as a starting point in Taphonomy when analyzing remains in sites whose preservation does not allow distinguishing who accumulated the assemblages through the analysis of the cut or tooth marks left on the surface of the bones.

“The future of Taphonomy involves using increasingly powerful statistical tools, like the ones we use here,” says Abel Moclán.

Source: CENIEH [March 15, 2019]



Meteor Activity Outlook for March 16-22, 2019

Oliver Staiger captured this impressive fireball while photographing aurora from Sandgerði, Iceland. © Oliver Staiger. For more information on this event refer to: https://fireball.amsmeteors.org/members/imo_view/event/2019/863

During this period the moon will reach its full phase on Wednesday March 20th. At this time the moon will be located opposite the sun and will lie above the horizon all night long. This weekend the waxing gibbous moon will set during the early morning hours, allowing a few hours of viewing meteor activity under dark conditions. Hourly meteor rates for evening observers this week is near 2 as seen from mid-northern latitudes (45N) and 3 as seen from tropical southern locations (25S). For morning observers the estimated total hourly rates should be near 7 as seen from mid-northern latitudes and 10 from the southern tropics. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Evening rates are slightly reduced during this period due to moonlight. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.

The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning March 16/17 . These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies near the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located far below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.

Radiant Positions at 20:00 Local Daylight Saving Time

Radiant Positions at 1:00 Local Daylight Saving Time

Radiant Positions at 5:00 Local Daylight Saving Time

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

The center of the large Anthelion (ANT) radiant is currently located at 12:36 (189) -04. This position lies in central Virgo, 3 degrees southwest of the 3rd magnitude double star known as Porrima (gamma Virginis). Due to the large size of this radiant, Anthelion activity may also appear from eastern Leo, and Crater as well as Virgo. This radiant is best placed near 0200 LST, when it lies on the meridian and is located highest in the sky. Rates at this time should be near 2 per hour no matter your location. With an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately 5 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 1 per hour. As seen from the tropical southern latitudes (25S), morning rates would be near 8 per hour as seen from rural observing sites and 2 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Evening rates are reduced during this period due to moonlight.

RA (RA in Deg.) DEC Km/Sec Local Daylight Saving Time North-South
Anthelion (ANT) 12:36 (189) -04 30 02:00 2 – 2 II

Source link

A Region of Bennu’s Northern Hemisphere Close Up

NASA – OSIRIS-REx Mission patch.

March 15, 2019

This trio of images acquired by NASA’s OSIRIS-REx spacecraft shows a wide shot and two close-ups of a region in asteroid Bennu’s northern hemisphere. The wide-angle image (left), obtained by the spacecraft’s MapCam camera, shows a 590-foot (180-meter) wide area with many rocks, including some large boulders, and a “pond” of regolith that is mostly devoid of large rocks. The two closer images, obtained by the high-resolution PolyCam camera, show details of areas in the MapCam image, specifically a 50-foot (15 meter) boulder (top) and the regolith pond (bottom). The PolyCam frames are 101 feet (31 meters) across and the boulder depicted is approximately the same size as a humpback whale.

OSIRIS-REx flyby Bennu asteroid

The images were taken on February 25 while the spacecraft was in orbit around Bennu, approximately 1.1 miles (1.8 km) from the asteroid’s surface. The observation plan for this day provided for one MapCam and two PolyCam images every 10 minutes, allowing for this combination of context and detail of Bennu’s surface.

OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer): http://www.nasa.gov/mission_pages/osiris-rex/index.html

Image, Animation, Text, Credits:  NASA/Karl Hille/Goddard/University of Arizona.

Greetings, Orbiter.chArchive link


    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...