понедельник, 29 июля 2019 г.

Stanton Drew Circles, Stanton Drew, Somerset, 25.7.19.


Stanton Drew Circles, Stanton Drew, Somerset, 25.7.19.











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TESS’s first-year of planet-hunting was out of this world

Have you ever looked up at the night sky and wondered … what other kinds of planets are out there? Our Transiting Exoplanet Survey Satellite (TESS) just spent its first year bringing us a step closer to exploring the planets around the nearest and brightest stars in the southern sky and is now doing the same in the north.


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TESS has been looking for dips in the brightness of stars that could be a sign of something we call “transits.” A transit happens when a planet passes between its star and us. It’s like when a bug flies in front of a light bulb. You may not notice the tiny drop in brightness when the bug blocks some of the light from reaching your eyes, but a sensitive camera could. The cameras on TESS are designed to detect those tiny drops in starlight caused by a transiting planet many light-years away.


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In the last year TESS has found 24 planets and more than 900 new candidate planets. And TESS is only halfway through its goal of mapping over three-fourths of our skies, which means there’s plenty more to discover!


TESS has been looking for planets around the closest, brightest stars because they will be the best planets to explore more thoroughly with future missions. We can even see a few of these stars with our own eyes, which means we’ve been looking at these planets for millions of years and didn’t even know it.


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We spent thousands of years staring at our closest neighbor, the Moon, and asking questions: What is it like? Could we live there? What is it made of (perhaps cheese?). Of course, now we can travel to the Moon and explore it ourselves (turns out, not made of cheese).


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But for the worlds TESS is discovering, the commute to answer those questions would be killer. It took 35 years for Voyager 1 to cross into interstellar space (the region between stars), and it’s zipping along at over 38,000 mph! At that rate it would take more than a half-a-million years to reach the nearest stars and planets that TESS is discovering.


While exploring these distant worlds in person isn’t an option, we have other ways of learning what they are like. TESS can tell us where a planet is, its size and its overall temperature, but observatories on the ground and in space like our upcoming James Webb Space Telescope will be able to learn even more — like whether or not a planet has an atmosphere and what it’s made of.


Here are a few of the worlds that our planet hunter discovered in the last year.


Earth-Sized Planet


The first Earth-sized planet discovered by TESS is about 90% the size of our home planet and orbits a star 53 light-years away. The planet is called HD 21749 c (what a mouthful!) and is actually the second planet TESS has discovered orbiting that star, which you can see in the southern constellation Reticulum.


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The planet may be Earth-sized, but it would not be a pleasant place to live. It’s very close to its star and could have a surface temperature of 800 degrees Fahrenheit, which would be like sitting inside a commercial pizza oven.


Water World?


The other planet discovered in that star system, HD 21749 b, is about three times Earth’s size and orbits the star every 36 days. It has the longest orbit of any planet within 100 light-years of our solar system detected with TESS so far.


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The planet is denser than Neptune, but isn’t made of rock. Scientists think it might be a water planet or have a totally new type of atmosphere. But because the planet isn’t ideal for follow-up study, for now we can only theorize what the planet is actually like. Could it be made of pudding? Maybe … but probably not.


Magma World


One of the first planets TESS discovered, called LHS 3844 b, is roughly Earth’s size, but is so close to its star that it orbits in just 11 hours. For reference, Mercury, which is more than two and a half times closer to the Sun than we are, completes an orbit in just under three months.


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Because the planet is so close to its star, the day side of the planet might get so hot that pools and oceans of magma form on its rocky surface, which would make for a rather unpleasant day at the beach.    


TESS’s Smallest Planet


The smallest planet TESS has discovered, called L 98-59 b, is between the size of Earth and Mars and orbits its star in a little over two days. Its star also hosts two other TESS-discovered worlds.


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Because the planet lies so close to its star, it gets 22 times the radiation we get here on Earth. Yikes! It is also not located in its star’s habitable zone, which means there probably isn’t any liquid water on the surface. Those two factors make it an unlikely place to find life, but scientists believe it will be a good candidate for follow-up studies by other telescopes.


Other Data


While TESS’s team is hunting for planets around close, bright stars, it’s also collecting information on all sorts of other things. From transits around dimmer, farther stars to other objects in our solar system and events outside our galaxy, data from TESS can help astronomers learn a lot more about the universe. Comets and black holes and supernovae, oh my!


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Interested in joining the hunt? TESS’s data are released online, so citizen scientists around the world can help us discover new worlds and better understand our universe.


Stay tuned for TESS’s next year of science as it monitors the stars that more than 6.5 billion of us in the northern hemisphere see every night.


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


‘Carwynnen Quoit’, a restored Prehistoric Dolmen, Cornwall, 23.7.19.




‘Carwynnen Quoit’, a restored Prehistoric Dolmen, Cornwall, 23.7.19.









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2019 July 29 Lightning over the Volcano of Water Image Credit…


2019 July 29


Lightning over the Volcano of Water
Image Credit & Copyright: Sergio Montúfar (Pinceladas Nocturnas)


Explanation: Have you ever watched a lightning storm in awe? Join the crowd. Details of what causes lightning are still being researched, but it is known that inside some clouds, internal updrafts cause collisions between ice and snow that slowly separate charges between cloud tops and bottoms The rapid electrical discharges that are lightning soon result. Lightning usually takes a jagged course, rapidly heating a thin column of air to about three times the surface temperature of the Sun. The resulting shock wave starts supersonically and decays into the loud sound known as thunder. On average, around the world, about 6,000 lightning bolts occur between clouds and the Earth every minute. Pictured earlier this month in a two-image composite, lightning stems from communication antennas near the top of Volcán de Agua (Volcano of Water) in Guatemala.


∞ Source: apod.nasa.gov/apod/ap190729.html


Electricity-driven undersea reactions may have been important for the emergence of life

Though it remains unknown how life began, there is a community of scientists who suspect it occurred in or around deep sea hydrothermal environments. At such sites, water heated by contact with hot rocks from Earth’s mantle flows into the lower ocean, passing over and through minerals which are themselves precipitated by the interaction of this hot water with cold seawater.











Electricity-driven undersea reactions may have been important for the emergence of life
The research group has proposed an effective mechanism to utilize the chemical energy generated
by hot hydrothermal fluids gushing out of hydrothermal vents on Earth’s early ocean floor
for the synthesis of biomolecules [Credit: ELSI]

The minerals often include metal sulfides, such as iron sulfide, also known as pyrite or fool’s gold. As they precipitate, these mineral precipitates begin to form channels for the hot vent water, and since the metal-containing minerals are electrically conductive and the compositions of the vent water and ocean water are different, an electrical gradient is created—something like a natural battery—with electric current flowing from the vent water through the minerals and into the ocean.
A team led by Tokyo Institute of Technology/Earth-Life Science Institute (ELSI) scientists have now shown via careful laboratory experiments that this current can reduce the metal sulfide minerals to native metals and mixed metal sulfide/metal conglomerates, which in turn can reduce and catalyze the reduction of various organic compounds.


The team led by Norio Kitadai, an affiliated scientist of the Tokyo Institute of Technology/Earth-Life Science Institute (ELSI) as well as a scientist at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), produced a set of electrochemical reactions in the laboratory that are suspected to have been generated in early ocean floor hydrothermal vent environments.











Electricity-driven undersea reactions may have been important for the emergence of life
Conceptual diagram of a hydrothermal vent assumed to have been widely distributed on the Hadean ocean floor.
Hydrogen and hydrogen sulfide contained in hydrothermal fluids are oxidized inside the vent, and the generated
 electrons flow away from the vent along the electric potential difference between hydrothermal fluids
and seawater, which generates a steady electric current (hydrothermal electricity generation)
[Credit: Kitadai et al. 2019]

They demonstrated that metal sulfides, including those of iron, copper, lead, and silver (some of which are common constituent minerals in hydrothermal vent environments), were converted to native metals by electroreduction. Complexes of metal sulfide and reduced metal were also produced during the process.


It was also discovered that several organic chemical reactions indispensable in modern life were promoted by these complexes. The authors believe the metals and metal sulfides served as reducing agents and catalysts for these reactions.


This research identifies a new mechanism for the creation of organic compounds driven by hydrothermal electricity generation in hydrothermal fluids. An exciting implication of this work is that, since electrical current appears to be universally generated in deep-sea hydrothermal vent environments on Earth, anywhere such hydrothermal processes occur throughout the cosmos should likewise promote this kind of chemistry.


Indeed, recent astronomical and spacecraft-based observations suggest there may be vigorous hydrothermal activity on the moons of Saturn and Jupiter (Enceladus and Europa), and hydrothermal activity was likely common on early Mars. Further research on the effects of various metals and electric gradients is expected to unveil much more about the environmental conditions that can facilitate prebiotic chemistry. This could ultimately lead to a better understanding of the universality and similarity of life in the universe.


The findings are published in Science Advances.


Source: Tokyo Institute of Technology [July 25, 2019]



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Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt’s...

Beneath the waves of the Mediterranean, underwater archaeologists were busy digging the sea-bed to uncover more secrets of the sunken cities of Heracleion and Canopus in Abu Qir Bay, in Alexandria.











Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt's submerged city Heracleion
Granite columns and a Greek temple were found during recent dives and studies in the ancient sunken
harbour city Heracleion, off Egypt ‘s north coast [Credit: Egypt. Ministry of Antiquities]

During the recent archaeological season, which was extended up until the past two months, the Egyptian-European mission led by Frank Goddio, Head of the European Underwater Archaeology Institute (Institut Européen d’Archéologie Sous-Marine) has succeeded in uncovering the remains of a large settlement, a temple, shipwrecks and a collection of coins and jewellery.











Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt's submerged city Heracleion
Byzantine era coin recovered from a wreck in the sunken harbour city Heracleion off Egypt ‘s north coast 
[Credit: Egypt. Ministry of Antiquities]

Ihab Fahmy, Head of the Underwater Archaeology Department at the ministry of antiquities, told Ahram Online that through using a sophisticated scanning and archaeological surveying device, the mission discovered that the city of Canopus is larger than previously thought.











Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt's submerged city Heracleion
Ptolemaic coin recovered from a wreck in the sunken harbour city Heracleion off Egypt ‘s north coast
[Credit: Egypt. Ministry of Antiquities]

It extends one kilometre south. Inside this extension, Fahmy told Ahram Online, the mission uncovered remains of a port, clay pots from the Saite period, bronze and gold coins from the Ptolemaic and Byzantine eras. Jewellery like rings and earrings was also unearthed











Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt's submerged city Heracleion
Well-preserved necklace recovered from a wreck in the sunken
 harbour city Heracleion off Egypt ‘s north coast
[Credit: Egypt. Ministry of Antiquities]

“This suggests that this city has been inhabited since the eight century BC until the Islamic period,” Fahmy said.











Sunken ancient Greek temple, shipwrecks, coins and jewellery found in Egypt's submerged city Heracleion
Archaeologists surveying in the remains of a shipwreck in the sunken 
harbour city Heracleion off Egypt ‘s north coast
[Credit: Egypt. Ministry of Antiquities]

In Heracleion, the mission found the remains of a new section of an ancient settlement with a new part of the city’s main temple, which has been completely destroyed, remains of another smaller Greek temple, as well as ancient columns and pottery from the third and fourth centuries B.C.E, and bronze coins from the reign of King Ptolemy II.


A shipwreck of a 13 metres long sunken ship was also found lying on the sea-bed. Inside it was a collection of coins and pots. Studies and research will be done on the wreck to know more about it.


Author: Nevine El-Aref | Source: Ahram Online [July 25, 2019]



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Israeli archaeologists discover 3,500-year-old Canaanite staircase

Israeli researchers have discovered a magnificent staircase that dates back to 3,500 years ago in the northern part of Israel, the Hebrew University of Jerusalem reported on Wednesday.











Israeli archaeologists discover 3,500-year-old Canaanite staircase
Stunning 8th century BCE staircase and paved entrance hall at Tel Hazor [Credit: The Selz Foundation
Hazor Excavations in Memory of Yigael Yadin]

The stairs were discovered during excavations to expose the palace of Hazor, which was the largest and most important Canaanite city in the Levant (the eastern part of the Mediterranean basin).


The stairs led from the wide cobblestone courtyard to the main entrance of the palace.


The staircase, about 4.5 meters wide, consists of basalt slabs. So far, seven steps have been exposed, and the archaeologists estimate that more steps will be unveiled in the direction of the palace.


The palace was destroyed about 3,400 years ago by a great fire in which the entire Canaanite city was ruined.


According to the archaeologists, the stairs indicate the architectural strength and grandeur of the palace.











Israeli archaeologists discover 3,500-year-old Canaanite staircase
Pottery shards, potentially broken in the 8th century BCE destruction of Hazor by Tiglath-Pileser III
[Credit: The Selz Foundation Hazor Excavations in Memory of Yigael Yadin]

In the past, Egyptian scarabs, 40 huge storage vessels, many basalt tools, raw materials related to the palace’s workshops were found in the palace.


Four royal inscriptions were discovered as well, three of them in Egyptian hieroglyphics writing and one in Akkadian language.


Two of the inscriptions were found on fragments of Egyptian statues: a Sphinx fragment of the Egyptian King Menkaure, who ruled around 2,500 BC, and an Egyptian official statue, who lived in the 18-19 centuries BC.


Tel Hazor, where the excavations are conducted, is declared a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization.


Source: Xinhua News Agency [July 26, 2019]



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A sign of communal sophistication revealed by finds in Neolithic site of Koutroulou...

A large, Middle Neolithic building was found at the top of the Koutroulou Magoula Neolithic settlement in Central Greece during this year’s excavation season, archaeologists said on Friday.











A sign of communal sophistication revealed by finds in Neolithic site of Koutroulou Magoula, Central Greece
Credit: Dr Nina Kyparissi-Apostolika,Ephorate
of Palaeoanthropology and Speleology

The building has stone walls measuring a total of 9.5 m in length and nearly 8.5 m wide, and is one of the largest of this period to be found in Greece. It also appears to have been supported by a massive external buttress. Its function remains unclear, but preliminary results indicate it was used over a long time and underwent rebuilding and modifications. At certain periods it also seems to have been shared with domestic animals.
Another significant find is a complex of heavily burnt, closed pottery kilns found near the edge of the settlement. One of the kilns preserves extremely well its plastered floor, parts of its plastered walls and dome, and other architectural features. It was built on a coarsely plastered platform. «This is an extremely important find, and an indication of the technological sophistication of the Neolithic inhabitants of the site,» noted Dr Nina Kyparissi-Apostolika, honorary ephor at the Ephorate of Palaeoanthropology and Speleology, and co-director of the excavation with professor Yannis Hamilakis of Brown University.











A sign of communal sophistication revealed by finds in Neolithic site of Koutroulou Magoula, Central Greece
Credit: Dr Nina Kyparissi-Apostolika,Ephorate
of Palaeoanthropology and Speleology

Excavations this year proved beyond any doubt that the settlement in the Neolithic was surrounded by perimeter ditches, large, seemingly communal works with multiple social, symbolic and practical functions. The natural bedrock had been cut by people in the Neolithic to form steps in order to facilitate digging, but also enable its continuous use for collecting water and possibly clay. «Given the size of the settlement, the time and effort invested in the creation and maintenance of this system of ditches would have phenomenal. These ditches would have been a central feature in the material and social life of the community,» noted professor Hamilakis.
This season’s findings included many clay figurines and house models, adding to the already impressive and diverse collection of figurines from the site which numbers more than 400 to date. Extensive ethnographic research was also carried out, and the season concluded with a site-specific theatrical performance titled «Woman» and staged next to the trenches. It was attended by more than 200 people and the theme merged archaeological narratives with contemporary discourses on gender relations.











A sign of communal sophistication revealed by finds in Neolithic site of Koutroulou Magoula, Central Greece
Credit: Dr Nina Kyparissi-Apostolika,Ephorate
of Palaeoanthropology and Speleology

The tell settlement of Koutroulou Magoula measures 3.7 hectares, rises around 6.6 m from the surrounding plain, and was occupied during the Middle Neolithic period (6000-5800 BCE); it was also used for burials during the Late Bronze Age (c. 15-14th centuries BCE) and the Medieval periods (c. 12th century AD).
The 10th season of the Koutroulou Magoula Archaeology and Archaeological Ethnography Project was competed last week. The project was launched officially 2010, and co-directed by Hamilakis and Kyparissi, is a collaboration between the Greek Archaeological Service and Brown University in Rhode Island, US. In the 2018 and 2019 seasons, the University College London also collaborated, under the directorship of Dr VasilisTsamis.


The excavation is carried out under the auspices of the British School at Athens, and in the 2019 field season included students and archaeologists from Greece, the US, the UK, the Netherlands, and Taiwan.


Source: Athens-Macedonian News Agency [July 26, 2019]



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Smoke Gets In Your Eyes…and Our Instruments

Fires are some of the most dynamic and dramatic natural phenomena. They can change rapidly, burning natural landscapes and human environments alike. Fires are a natural part of many of Earth’s ecosystems, necessary to replenish soil and for healthy plant growth. But, as the planet warms, fires are becoming more intense, burning longer and hotter.


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Right now, a fleet of vehicles and a team of scientists are in the field, studying how smoke from those fires affects air quality, weather and climate. The mission? It’s called FIREX-AQ. They’re working from the ground up to the sky to measure smoke, find out what’s in it, and investigate how it affects our lives.


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Starting on the ground, the Langley Aerosol Research Group Experiment (LARGE) operates out of a large van. It’s one of two such vans working with the campaign. It looks a little like a food truck, but instead of a kitchen, the inside is packed full of science instruments.


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The team drives the van out into the wilderness to take measurements of smoke and tiny particles in the air at the ground level. This is important for a few reasons: First of all, it’s the stuff we’re breathing! It also gives us a look at smoke overnight, when the plumes tend to sink down out of the atmosphere and settle near the ground until temperatures heat back up with the Sun. The LARGE group camps out with their van full of instruments, taking continuous measurements of smoke…and not getting much sleep.


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Just a little higher up, NOAA’s Twin Otter aircraft can flit down close to where the fires are actually burning, taking measurements of the smoke and getting a closer look at the fires themselves. The Twin Otters are known as “NOAA’s workhorses” because they’re easily maneuverable and can fly nice and slow to gather measurements, topping out at about 17,000 feet.


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Then, sometimes flying at commercial plane height (30,000 feet) and swooping all the way down to 800 feet above the ground, NASA’s DC-8 is packed wing to wing with science instruments. The team onboard the DC-8 is looking at more than 200 different chemicals in the smoke.


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The DC-8 does some fancy flying, crisscrossing over the fires in a maneuver called “the lawnmower” and sometimes spiraling down over one vertical column of air to capture smoke and particles at all different heights. Inside, the plane is full of instrument racks and tubing, capturing external air and measuring its chemical makeup. Fun fact: The front bathroom on the DC-8 is closed during science flights to make sure the instruments don’t accidentally measure anything ejected from the plane.


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Finally, we make it all the way up to space. We’ve got a few different mechanisms for studying fires already mounted on satellites. Some of the satellites can see where active fires are burning, which helps scientists and first responders keep an eye on large swaths of land.


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Some satellites can see smoke plumes, and help researchers track them as they move across land, blown by wind.


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Other satellites help us track weather and forecast how the fires might behave. That’s important for keeping people safe, and it helps the FIREX-AQ team know where to fly and drive when they’ll get the most information. These forecasts use computer models, based on satellite observations and data about how fires and smoke behave. FIREX-AQ’s data will be fed back into these models to make them even more accurate.


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Learn more about how NASA is studying fires from the field, here.


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


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