четверг, 6 февраля 2020 г.

Roman Dedication Stone, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.

Roman Dedication Stone, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.



* This article was originally published here

New thalattosaur species discovered in Southeast Alaska


Scientists at the University of Alaska Fairbanks have identified a new species of thalattosaur, a marine reptile that lived more than 200 million years ago.

New thalattosaur species discovered in Southeast Alaska
Artist's depiction of Gunakadeit joseeae [Credit: Ray Troll ©2020]
The new species, Gunakadeit joseeae, is the most complete thalattosaur ever found in North America and has given paleontologists new insights about the thalattosaurs' family tree, according to a paper published in the journal Scientific Reports. Scientists found the fossil in Southeast Alaska in 2011.

Thalattosaurs were marine reptiles that lived more than 200 million years ago, during the mid to late Triassic Period, when their distant relatives -- dinosaurs -- were first emerging. They grew to lengths of up to 3-4 meters and lived in equatorial oceans worldwide until they died out near the end of the Triassic.

"When you find a new species, one of the things you want to do is tell people where you think it fits in the family tree," said Patrick Druckenmiller, the paper's lead author and director and earth sciences curator at the University of Alaska Museum of the North. "We decided to start from scratch on the family tree."


Prior to the discovery of Gunakadeit joseeae, it had been two decades since scientists had thoroughly updated thalattosaur interrelationships, Druckenmiller said. The process of re-examining a prehistoric animal's family tree involves analyzing dozens and dozens of detailed anatomical features from fossil specimens worldwide, then using computers to analyze the information to see how the different species could be related.

Druckenmiller said he and collaborator Neil Kelley from Vanderbilt University were surprised when they identified where Gunakadeit joseeae landed.

"It was so specialized and weird, we thought it might be out at the furthest branches of the tree," he said. Instead it's a relatively primitive type of thalattosaur that survived late into the existence of the group.

"Thalattosaurs were among the first groups of land-dwelling reptiles to readapt to life in the ocean," Kelley said. "They thrived for tens of millions of years, but their fossils are relatively rare so this new specimen helps fill an important gap in the story of their evolution and eventual extinction."

New thalattosaur species discovered in Southeast Alaska
The fossil of Gunakadeit joseeae, which was found in Southeast Alaska. About two thirds of the tail had already
 eroded away when the fossil was discovered [Credit: University of Alaska Museum of the North]
That the fossil was found at all is a remarkable. It was located in rocks in the intertidal zone. The site is normally underwater all but a few days a year. In Southeast Alaska, when extreme low tides hit, people head to the beaches to explore. That's exactly what Jim Baichtal, a geologist with the U.S. Forest Service's Tongass National Forest, was doing on May 18, 2011, when low tides of -3.7 feet were predicted.

He and a few colleagues, including Gene Primaky, the office's information technology professional, headed out to the Keku Islands near the village of Kake to look for fossils. Primaky saw something odd on a rocky outcrop and called over Baichtal, "Hey Jim! What is this?" Baichtal immediately recognized it as a fossilized intact skeleton. He snapped a photo with his phone and sent it to Druckenmiller.

A month later, the tides were forecasted to be almost that low, -3.1 feet, for two days. It was the last chance they would have to remove the fossil during daylight hours for nearly a year, so they had to move fast. The team had just four hours each day to work before the tide came in and submerged the fossil.

"We rock-sawed like crazy and managed to pull it out, but just barely," Druckenmiller said. "The water was lapping at the edge of the site."


Once the sample was back at the UA Museum of the North, a fossil preparation specialist worked in two-week stints over the course of several years to get the fossil cleaned up and ready for study.

When they saw the fossil's skull, they could tell right away that it was something new because of its extremely pointed snout, which was likely an adaptation for the shallow marine environment where it lived.

"It was probably poking its pointy schnoz into cracks and crevices in coral reefs and feeding on soft-bodied critters," Druckenmiller said. Its specialization may have been what ultimately led to its extinction. "We think these animals were highly specialized to feed in the shallow water environments, but when the sea levels dropped and food sources changed, they had nowhere to go."

Once the fossil was identified as a new species, it needed a name. To honor the local culture and history, elders in Kake and representatives of Sealaska Corp. agreed the Tlingit name "Gunakadeit" would be appropriate. Gunakadeit is a sea monster of Tlingit legend that brings good fortune to those who see it. The second part of the new animal's name, joseeae, recognizes Primaky's mother, Josee Michelle DeWaelheyns.

Source: University of Alaska Fairbanks [February 04, 2020]



* This article was originally published here

MY COLLECTION OF STRANGE GOINGS ON.

402 views   51 likes   3 dislikes  

Channel: Terry's Theories  

Video two of two this is a collection of photos and videos that I have acquired over 2019. There will be at least one or two more videos in this series. In the next video I will start off with orbs and spheres then move on to the sun and then cover Phobos one and two the final hrs and then wrap up with Mars and some of her mysteries.
I really hope you guys will enjoy my videos.If you have any suggestions or wish to email me please do so at terrystheories@outlook.com
If any of you guys would like to donate to Terry's Theories the proceeds will go towards computer equipment such as an external hard drive and webcam.
paypal : https://www.paypal.me/Franklin1275?locale.x=en_US

Source of video information all can be found at Terry's Theories
https://www.youtube.com/channel/UCtPEOm9TEq05rnECm78fhMg?view_as=subscriber

Video length: 13:16
Category: Science & Technology
21 comments

Prehistoric Fossil Shell Pendant, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.

Prehistoric Fossil Shell Pendant, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.



* This article was originally published here

How Earth climate models help picture life on unimaginable worlds


In a generic brick building on the northwestern edge of NASA's Goddard Space Flight Center campus in Greenbelt, Maryland, thousands of computers packed in racks the size of vending machines hum in a deafening chorus of data crunching. Day and night, they spit out 7 quadrillion calculations per second. These machines collectively are known as NASA's Discover supercomputer and they are tasked with running sophisticated climate models to predict Earth's future climate.

How Earth climate models help picture life on unimaginable worlds
Illustration of an exoplanet [Credit: NASA's Goddard Space Flight Center/Chris Smith]
But now, they're also sussing out something much farther away: whether any of the more than 4,000 curiously weird planets beyond our solar system discovered in the past two decades could support life.

Scientists are finding that the answer not only is yes, but that it's yes under a range of surprising conditions compared to Earth. This revelation has prompted many of them to grapple with a question vital to NASA's search for life beyond Earth. Is it possible that our notions of what makes a planet suitable for life are too limiting?

The next generation of powerful telescopes and space observatories will surely give us more clues. These instruments will allow scientists for the first time to analyze the atmospheres of the most tantalizing planets out there: rocky ones, like Earth, that could have an essential ingredient for life—liquid water—flowing on their surfaces.


For the time being, it's difficult to probe far-off atmospheres. Sending a spacecraft to the closest planet outside our solar system, or exoplanet, would take 75,000 years with today's technology. Even with powerful telescopes nearby exoplanets are virtually impossible to study in detail. The trouble is that they're too small and too drowned out by the light of their stars for scientists to make out the faint light signatures they reflect—signatures that could reveal the chemistry of life at the surface.

In other words, detecting the ingredients of the atmospheres around these phantom planets, as many scientists like to point out, is like standing in Washington, D.C., and trying to glimpse a firefly next to a searchlight in Los Angeles. This reality makes climate models critical to exploration, said chief exoplanetary scientist Karl Stapelfeldt, who's based at NASA's Jet Propulsion Laboratory in Pasadena, California.

"The models make specific, testable predictions of what we should see," he said. "These are very important for designing our future telescopes and observing strategies."

Is the Solar System a Good Role Model?

In scanning the cosmos with large ground-based and space telescopes, astronomers have discovered an eclectic assortment of worlds that seem drawn from the imagination.

How Earth climate models help picture life on unimaginable worlds
When a planet crosses directly between us and its star, we see the star dim slightly because the planet is blocking out a 
portion of the light. Measuring these dips in starlight is one technique, which is known as the “transit method,” that 
scientists use to identify exoplanets. Scientists make a plot called a “light curve” which shows the brightness of the 
star over time. Using this plot, scientists can see what percentage of the star's light the planet blocks and how long
 it takes the planet to cross the disk of the star, information that helps them estimate the planet's distance
 from the star and its mass [Credit: NASA's Goddard Space Flight Center]
"For a long time, scientists were really focused on finding Sun- and Earth-like systems. That's all we knew," said Elisa Quintana, a NASA Goddard astrophysicist who led the 2014 discovery of Earth-sized planet Kepler-186f. "But we found out that there's this whole crazy diversity in planets. We found planets as small as the Moon. We found giant planets. And we found some that orbit tiny stars, giant stars and multiple stars."

Indeed, most of the planets detected by NASA's Kepler space telescope and the new Transiting Exoplanet Survey Satellite, as well as ground-based observations, don't exist in our solar system. They fall between the size of a terrestrial Earth and a gaseous Uranus, which is four times bigger than this planet.

Planets closest in size to Earth, and most likely in theory to have habitable conditions, so far have been found only around "red dwarf" stars, which make up a vast majority of stars in the galaxy. But that's likely because red dwarfs are smaller and dimmer than the Sun, so the signal from planets orbiting them is easier for telescopes to detect.


Because red dwarfs are small, planets have to lap uncomfortably close—closer than Mercury is to the Sun—to stay gravitationally attached to them. And because red dwarfs are cool, compared to all other stars, planets have to be closer to them to draw enough heat to allow liquid water to pool on their surfaces.

Among the most alluring recent discoveries in red dwarf systems are planets like Proxima Centauri b, or simply Proxima b. It's the closest exoplanet. There are also seven rocky planets in the nearby system TRAPPIST-1. Whether or not these planets could sustain life is still a matter of debate. Scientists point out that red dwarfs can spew up to 500 times more harmful ultraviolet and X-ray radiation at their planets than the Sun ejects into the solar system. On the face of it, this environment would strip atmospheres, evaporate oceans and fry DNA on any planet close to a red dwarf.

Yet, maybe not. Earth climate models are showing that rocky exoplanets around red dwarfs could be habitable despite the radiation.

The Magic is in the Clouds

Anthony Del Genio is a recently retired planetary climate scientist from NASA's Goddard Institute for Space Studies in New York City. During his career he simulated the climates of Earth and of other planets, including Proxima b.

How Earth climate models help picture life on unimaginable worlds
In 2014, NASA's Swift mission detected a record-setting series of X-ray flares unleashed by DG CVn, a nearby binary
 consisting of two red dwarf stars, illustrated here. At its peak, the initial flare was brighter in X-rays 
than the combined light from both stars at all wavelengths under normal conditions
[Credit: NASA's Goddard Space Flight Center]
Del Genio's team recently simulated possible climates on Proxima b to test how many would leave it warm and wet enough to host life. This type of modeling work helps NASA scientists identify a handful of promising planets worthy of more rigorous study with NASA's forthcoming James Webb Space Telescope.

"While our work can't tell observers if any planet is habitable or not, we can tell them whether a planet is smack in the midrange of good candidates to search further," Del Genio said.

Proxima b orbits Proxima Centauri in a three-star system located just 4.2 light years from the Sun. Besides that, scientists don't know much about it. They believe it's rocky, based on its estimated mass, which is slightly larger than Earth's. Scientists can infer mass by watching how much Proxima b tugs on its star as it orbits it.


The problem with Proxima b is that it's 20 times closer to its star than Earth is to the Sun. Therefore, it takes the planet only 11.2 days to make one orbit (Earth takes 365 days to orbit the Sun once). Physics tells scientists that this cozy arrangement could leave Proxima b gravitationally locked to its star, like the Moon is gravitationally locked to Earth. If true, one side of Proxima b faces the star's intense radiation while the other one freezes in the darkness of space in a planetary recipe that doesn't bode well for life on either side.

But Del Genio's simulations show that Proxima b, or any planet with similar characteristics, could be habitable despite the forces conspiring against it. "And the clouds and oceans play a fundamental role in that," Del Genio said.

Del Genio's team upgraded an Earth climate model first developed in the 1970s to create a planetary simulator called ROCKE-3-D. Whether Proxima b has an atmosphere is an open and critical question that will hopefully be settled by future telescopes. But Del Genio's team assumed that it does.

With each simulation Del Genio's team varied the types and amounts of greenhouse gases in Proxima b's air. They also changed the depth, size, and salinity of its oceans and adjusted the ratio of land to water to see how these tweaks would influence the planet's climate.


Models such as ROCKE-3-D begin with only grains of basic information about an exoplanet: its size, mass, and distance from its star. Scientists can infer these things by watching the light from a star dip as a planet crosses in front of it, or by measuring the gravitational tugging on a star as a planet circles it.

These scant physical details inform equations that comprise up to a million lines of computer code needed to build the most sophisticated climate models. The code instructs a computer like NASA's Discover supercomputer to use established rules of nature to simulate global climate systems. Among many other factors, climate models consider how clouds and oceans circulate and interact and how radiation from a sun interacts with a planet's atmosphere and surface.

When Del Genio's team ran ROCKE-3-D on Discover they saw that Proxima b's hypothetical clouds acted like a massive sun umbrella by deflecting radiation. This could lower the temperature on Proxima b's sun-facing side from too hot to warm.


Other scientists have found that Proxima b could form clouds so massive they would blot out the entire sky if one were looking up from the surface.

"If a planet is gravitationally locked and rotating slowly on its axis a circle of clouds forms in front of the star, always pointing towards it. This is due to a force known as the Coriolis effect, which causes convection at the location where the star is heating the atmosphere," said Ravi Kopparapu, a NASA Goddard planetary scientist who also models the potential climates of exoplanets. "Our modeling shows that Proxima b could look like this."

In addition to making Proxima b's day side more temperate than expected, a combination of atmosphere and ocean circulation would move warm air and water around the planet, thereby transporting heat to the cold side. "So you not only keep the atmosphere on the night side from freezing out, you create parts on the night side that actually maintain liquid water on the surface, even though those parts see no light," Del Genio said.

Taking a New Look at an Old Role Model

Atmospheres are envelopes of molecules around planets. Besides helping maintain and circulate heat, atmospheres distribute gases that nourish life or are produced by it.

How Earth climate models help picture life on unimaginable worlds
This is an excerpt of Fortran code from the ROCKE-3D model that calculates the details of the orbit of any planet
around its star. This has been modified from the original Earth model so that it can handle any kind of planet in
any kind of orbit, including planets that are "tidally locked," with one side always facing the star. This code is
 needed to predict how high in the sky of a planet the star is at any time, and thus how strongly heated
the planet is, how long day and night are, whether there are seasons, and if so, how long they are
[Credit: NASA’s Goddard Institute for Space Studies/Anthony Del Genio]
These gases are the so-called "biosignatures" scientists will look for in the atmospheres of exoplanets. But what exactly they should be looking for is still undecided.

Earth's is the only evidence scientists have of the chemistry of a life-sustaining atmosphere. Yet, they have to be cautious when using Earth's chemistry as a model for the rest of the galaxy. Simulations from Goddard planetary scientist Giada Arney, for instance, show that even something as simple as oxygen—the quintessential sign of plant life and photosynthesis on modern Earth—could present a trap.


Arney's work highlights something interesting. Had alien civilizations pointed their telescopes toward Earth billions of years ago hoping to find a blue planet swimming in oxygen, they would have been disappointed; maybe they would have turned their telescopes toward another world. But instead of oxygen, methane could have been the best biosignature to look for 3.8 to 2.5 billion years ago. This molecule was produced in abundance back then, likely by the microorganisms quietly flourishing in the oceans.

"What is interesting about this phase of Earth's history is that it was so alien compared to modern Earth," Arney said. "There was no oxygen yet, so it wasn't even a pale blue dot. It was a pale orange dot," she said, referencing the orange haze produced by the methane smog that may have shrouded early Earth.

Findings like this one, Arney said, "have broadened our thinking about what's possible among exoplanets," helping expand the list of biosignatures planetary scientists will look for in distant atmospheres.

Building a Blueprint for Atmosphere Hunters

While the lessons from planetary climate models are theoretical—meaning scientists haven't had an opportunity to test them in the real world—they offer a blueprint for future observations.

How Earth climate models help picture life on unimaginable worlds
NASA scientists now have the most complete global picture of life on Earth to date. From the unique vantage point
of space, NASA observes not only Earth’s landmasses and oceans but also the organisms that live among them
[Credit: NASA's Goddard Space Flight Center]
One major goal of simulating climates is to identify the most promising planets to turn to with the Webb telescope and other missions so that scientists can use limited and expensive telescope time most efficiently. Additionally, these simulations are helping scientists create a catalog of potential chemical signatures that they will one day detect. Having such a database to draw from will help them quickly determine the type of planet they're looking at and decide whether to keep probing or turn their telescopes elsewhere.

Discovering life on distant planets is a gamble, Del Genio noted: "So if we want to observe most wisely, we have to take recommendations from climate models, because that's just increasing the odds."

Author: Lonnie Shekhtman | Source: NASA's Goddard Space Flight Center [January 25, 2020]



* This article was originally published here

Первый снег в Одесса зимнего сезона 2019-2020го

23 views   likes   dislikes  

Channel: Рассим Благодарь  

Впервые за зиму 2019-2020 го в одесской области выпал устойчивый снег который продержался как минимум один день. Съёмка снега выпавшего в ночь с 5 на 6 февраля.For the first time in the winter of 2019-2020, in the Odessa region, stable snow fell which lasted at least one day.

Video length: 2:28
Category: Entertainment
2 comments

Prehistoric Rock Art Fragments and Ancient Querns, Whitby Museum and Art Gallery, Whitby, North...

Prehistoric Rock Art Fragments and Ancient Querns, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.



* This article was originally published here

Tarantula Nebula spins web of mystery in Spitzer image


The Tarantula Nebula, seen in this image by the Spitzer Space Telescope, was one of the first targets studied by the infrared observatory after its launch in 2003, and the telescope has revisited it many times since. Now that Spitzer is set to be retired on Jan. 30, 2020, scientists have generated a new view of the nebula from Spitzer data.

Tarantula Nebula spins web of mystery in Spitzer image
This image from NASA's Spitzer Space Telescope shows the Tarantula Nebula in two wavelengths of infrared light.
The red regions indicate the presence of particularly hot gas, while the blue regions are interstellar dust
 that is similar in composition to ash from coal or wood-burning fires on Earth
[Credit: NASA/JPL-Caltech]
This high-resolution image combines data from multiple Spitzer observations, most recently in February and September 2019.

"I think we chose the Tarantula Nebula as one of our first targets because we knew it would demonstrate the breadth of Spitzer's capabilities," said Michael Werner, who has been Spitzer's project scientist since the mission's inception and is based at NASA's Jet Propulsion Laboratory in Pasadena, California. "That region has a lot of interesting dust structures and a lot of star formation happening, and those are both areas where infrared observatories can see a lot of things that you can't see in other wavelengths."


Infrared light is invisible to the human eye, but some wavelengths of infrared can pass through clouds of gas and dust where visible light cannot. So scientists use infrared observations to view newborn stars and still-forming "protostars," swaddled in the clouds of gas and dust from which they formed.

Located in the Large Magellanic Cloud—a dwarf galaxy gravitationally bound to our Milky Way galaxy—the Tarantula Nebula is a hotbed of star formation. In the case of the Large Magellanic Cloud, such studies have helped scientists learn about rates of star formation in galaxies other than the Milky Way.

Tarantula Nebula spins web of mystery in Spitzer image
This annotated image from NASA's Spitzer Space Telescope shows the Tarantula Nebula in infrared light.
The supernova 1987A and the starburst region R136 are noted. The magenta-colored regions are
 primarily interstellar dust that is similar in composition to ash from coal or wood fires on Earth
[Credit: NASA/JPL-Caltech]
The nebula also hosts R136, a "starburst" region, where massive stars form in extremely close proximity and at a rate far higher than in the rest of the galaxy. Within R136, in an area less than 1 light-year across (about 6 trillion miles, or 9 trillion kilometers), there are more than 40 massive stars, each containing at least 50 times the mass of our Sun.

By contrast, there are no stars at all within 1 light-year of our Sun. Similar starburst regions have been found in other galaxies, containing dozens of massive stars—a higher number of massive stars than what is typically found in the rest of their host galaxies. How these starburst regions arise remains a mystery.


On the outskirts of the Tarantula Nebula, you can also find one of astronomy's most-studied stars that has exploded in a supernova. Dubbed 1987A because it was the first supernova spotted in 1987, the exploded star burned with the power of 100 million Suns for months. The shockwave from that event continues to move outward into space, encountering material ejected from the star during its dramatic death.

When the shockwave collides with dust, the dust heats up and begins to radiate in infrared light. In 2006, Spitzer observations saw that light and determined that the dust is largely composed of silicates, a key ingredient in the formation of rocky planets in our solar system. In 2019, scientists used Spitzer to study 1987A to monitor the changing brightness of the expanding shockwave and debris to learn more about how these explosions change their surrounding environment.

Source: NASA Jet Propulsion Laboratory [January 27, 2020]



* This article was originally published here

Roman Statue of Mithras, Great North Museum, Hancock, Newcastle upon Tyne, January 2020.

Roman Statue of Mithras, Great North Museum, Hancock, Newcastle upon Tyne, January 2020.



* This article was originally published here

Mystery at Mars pole explained


In 1966, two Caltech scientists were ruminating on the implications of the thin carbon dioxide (CO2) Martian atmosphere first revealed by Mariner IV, a NASA fly-by spacecraft built and flown by JPL. They theorized that Mars, with such an atmosphere, could have a long-term stable polar deposit of CO2 ice that, in turn, would control global atmospheric pressure.

Mystery at Mars pole explained
Credit: NASA/JPL/Malin Space Science Systems
A new study from Caltech suggests that the theory, developed by physicist Robert B. Leighton (BS '41, MS '44, Ph.D. '47) and planetary scientist Bruce C. Murray, may indeed be correct.

Carbon dioxide makes up more than 95 percent of Mars's atmosphere, which has a surface pressure of only 0.6 percent that of Earth. One prediction of Leighton's and Murray's theory—with enormous implications for climate change on Mars—is that its atmospheric pressure would swing in value as the planet wobbles on its axis during its orbit around the sun, exposing the poles to more or less sunlight. Direct sunlight on the CO2 ice deposited at the poles leads to its sublimation (the direct transition of a material from a solid to a gaseous state). Leighton and Murray predicted that, as exposure to sunlight shifts, atmospheric pressure could swing from just one-quarter that of today's Martian atmosphere to twice that of today over cycles of tens of thousands of years.

Now, a new model by Peter Buhler, Ph.D. of JPL, which Caltech manages for NASA, and colleagues from Caltech, JPL, and the University of Colorado, provides key evidence to support this. The model was described in a paper published in the journal Nature Astronomy.


The team explored the existence of a mysterious feature at the south pole of Mars: a massive deposit of CO2 ice and water ice in alternating strata, like the layers of a cake, that extend to a depth of 1 kilometer, with a thin frosting of CO2 ice at the top. The layer-cake deposit contains as much CO2 as in the entire Martian atmosphere today.

In theory, that layering should not be possible because water ice is more thermally stable and darker than CO2 ice; CO2 ice, scientists long believed, would quickly destabilize if it was buried underneath water ice. However, the new model by Buhler and colleagues shows that the deposit could have evolved as a result of the combination of three factors: 1) the changing obliquity (or tilt) of the planet's rotation, 2) the difference in the way water ice and CO2 ice reflect sunlight, and 3) the increase in atmospheric pressure that occurs when CO2 ice sublimes.

"Usually, when you run a model, you don't expect the results to match so closely to what you observe. But the thickness of the layers, as determined by the model, matches beautifully with radar measurements from orbiting satellites," says Buhler.

Here's how the deposit formed, the researchers suggest: as Mars wobbled on its rotational axis over the past 510,000 years, the south pole received varying amounts of sunlight, allowing CO2 ice to form when the poles were receiving less sunlight and causing it to sublime when the poles were sunnier. When CO2 ice formed, small amounts of water ice were trapped along with the CO2 ice. When the CO2 sublimed, the more stable water ice was left behind and consolidated into layers.


But the water layers do not totally seal the deposit. Instead, the subliming CO2 raises Mars's atmospheric pressure, and the layer cake with CO2 ice evolves in equilibrium with the atmosphere. When the sunlight starts declining again, a new CO2 ice layer forms on top of the water layer, and the cycle repeats.

Because sublimation episodes have generally been declining in intensity, some CO2 ice was left behind between the water layers—thus, the alternation of CO2 and water ice. The deepest (and therefore oldest) CO2 layer formed 510,000 years ago following the last period of extreme polar sunlight, when all the CO2 sublimed into the atmosphere.

"Our determination of the history of Mars's large pressure swings is fundamental to understanding the evolution of Mars's climate, including the history of liquid water stability and habitability near Mars's surface," Buhler says. This work was part of Buhler's thesis work at Caltech. He continued the research in his current role as a postdoctoral researcher at JPL. His co-authors are his former advisers Andy Ingersoll and Bethany Ehlmann, both professors of planetary science at Caltech; Sylvain Piqueux of JPL; and Paul Hayne of the University of Colorado, Boulder.

Source: California Institute of Technology [January 28, 2020]



* This article was originally published here

Three Neolithic Tools and a Bronze Age Arrow Head, Whitby Museum and Art Gallery, Whitby, North...

Three Neolithic Tools and a Bronze Age Arrow Head, Whitby Museum and Art Gallery, Whitby, North Yorkshire, 2.2.20.



* This article was originally published here

NSF's newest solar telescope produces first images, most detailed images of the sun


Just released first images from the National Science Foundation's Daniel K. Inouye Solar Telescope reveal unprecedented detail of the sun's surface and preview the world-class products to come from this preeminent 4-meter solar telescope. NSF's Inouye Solar Telescope will enable a new era of solar science and a leap forward in understanding the sun and its impacts on our planet.

NSF's newest solar telescope produces first images, most detailed images of the sun
The Daniel K. Inouye Solar Telescope has produced the highest resolution image of the sun's surface ever taken. In this
picture, taken at 789 nanometers (nm), we can see features as small as 30km (18 miles) in size for the first time ever.
The image shows a pattern of turbulent, "boiling" gas that covers the entire sun. The cell-like structures -- each
about the size of Texas -- are the signature of violent motions that transport heat from the inside of the sun to its
surface. Hot solar material (plasma) rises in the bright centers of "cells," cools off and then sinks below the surface
 in dark lanes in a process known as convection. In these dark lanes we can also see the tiny, bright markers of
magnetic fields. Never before seen to this clarity, these bright specks are thought to channel energy up into
the outer layers of the solar atmosphere called the corona. These bright spots may be at the core of why
the solar corona is more than a million degrees [Credit: NSO/AURA/NSF]
Activity on the sun, known as space weather, can affect systems on Earth. Magnetic eruptions on the sun can impact air travel, disrupt satellite communications and bring down power grids, causing long-lasting blackouts and disabling technologies such as GPS.

This first images from NSF's Inouye Solar Telescope show a close-up view of the sun's surface, which can provide important detail for scientists. The image shows a pattern of turbulent "boiling" plasma that covers the entire sun. The cell-like structures - each about the size of Texas - are the signature of violent motions that transport heat from the inside of the sun to its surface. That hot solar plasma rises in the bright centers of "cells," cools off and then sinks below the surface in dark lanes in a process known as convection. (See video available with this news release.)

"Since NSF began work on this ground-based telescope, we have eagerly awaited the first images," said France Córdova, NSF director. "We can now share these images and videos, which are the most detailed of our sun to date. NSF's Inouye Solar Telescope will be able to map the magnetic fields within the sun's corona, where solar eruptions occur that can impact life on Earth. This telescope will improve our understanding of what drives space weather and ultimately help forecasters better predict solar storms."


Illuminating what we know about our nearest star

The sun is our nearest star -- a gigantic nuclear reactor that burns about 5 million tons of hydrogen fuel every second. It has been doing so for about 5 billion years and will continue for the other 4.5 billion years of its lifetime. All that energy radiates into space in every direction, and the tiny fraction that hits Earth makes life possible. In the 1950s, scientists figured out that a solar wind blows from the sun to the edges of the solar system. They also deduced for the first time that we live inside the atmosphere of this star. But many of the sun's most vital processes continue to confound scientists.

"On Earth, we can predict if it is going to rain pretty much anywhere in the world very accurately, and space weather just isn't there yet," said Matt Mountain president of the Association of Universities for Research in Astronomy, which manages the Inouye Solar Telescope. "Our predictions lag behind terrestrial weather by 50 years, if not more. What we need is to grasp the underlying physics behind space weather, and this starts at the sun, which is what the Inouye Solar Telescope will study over the next decades."

Solar magnetic fields constantly get twisted and tangled by the motions of the sun's plasma. Twisted magnetic fields can lead to solar storms that can negatively affect our technology-dependent modern lifestyles. During 2017's Hurricane Irma, the National Oceanic and Atmospheric Administration reported that a simultaneous space weather event brought down radio communications used by first responders, aviation and maritime channels for eight hours on the day the hurricane made landfall.

NSF's newest solar telescope produces first images, most detailed images of the sun
The NSF's Inouye Solar Telescope images the sun in more detail than we've ever seen before. The telescope can image
a region of the sun 38,000km wide. Close up, these images show large cell-like structures hundreds of kilometers
across and, for the first time, the smallest features ever seen on the solar surface, some as small as 30km
[Credit: NSO/AURA/NSF]
Finally resolving these tiny magnetic features is central to what makes the Inouye Solar Telescope unique. It can measure and characterize the sun's magnetic field in more detail than ever seen before and determine the causes of potentially harmful solar activity.

"It's all about the magnetic field," said Thomas Rimmele, director of the Inouye Solar Telescope. "To unravel the sun's biggest mysteries, we have to not only be able to clearly see these tiny structures from 93 million miles away but very precisely measure their magnetic field strength and direction near the surface and trace the field as it extends out into the million-degree corona, the outer atmosphere of the sun."


Better understanding the origins of potential disasters will enable governments and utilities to better prepare for inevitable future space weather events. It is expected that notification of potential impacts could occur earlier - as much as 48 hours ahead of time instead of the current standard, which is about 48 minutes. This would allow for more time to secure power grids and critical infrastructure and to put satellites into safe mode.

The engineering

To achieve the proposed science, this telescope required important new approaches to its construction and engineering. Built by NSF's National Solar Observatory and managed by AURA, the Inouye Solar Telescope combines a 13-foot (4-meter) mirror - the world's largest for a solar telescope - with unparalleled viewing conditions at the 10,000-foot Haleakalā summit.

Focusing 13 kilowatts of solar power generates enormous amounts of heat - heat that must be contained or removed. A specialized cooling system provides crucial heat protection for the telescope and its optics. More than seven miles of piping distribute coolant throughout the observatory, partially chilled by ice created on site during the night.

Комментариев нет:

Fast Radio Burst Observations Deepen Astronomical Mystery

Image of the host galaxy of FRB 180916 (center) acquired on Hawaii’s Maunakea with the 8-meter Gemini North telescope of the international Gemini Observatory (a program of the NSF’s OIR Lab). Images acquired in SDSS g', r', and z' filters are used for the blue, green, and red colors, respectively. The position of the FRB in the spiral arm of the galaxy is marked by a green circle. Credit: Gemini Observatory/NSF’s Optical-Infrared Astronomy Research Laboratory/AURA.  download JPG | TIFF - download unannotated images JPG | TIFF

Observations with the 8-meter Gemini North telescope, a program of the NSF’s National Optical-Infrared Astronomy Research Laboratory, have allowed astronomers to pinpoint the location of a Fast Radio Burst in a nearby galaxy — making it the closest known example to Earth and only the second repeating burst source to have its location pinpointed in the sky. The source of this burst of radio waves is located in an environment radically different from that seen in previous studies. This discovery challenges researchers’ assumptions on the origin of these already enigmatic extragalactic events.

An unsolved mystery in astronomy has become even more puzzling. The source of Fast Radio Bursts (FRBs) — sudden bursts of radio waves lasting a few thousandths of a second — has remained unknown since their discovery in 2007. Research published today in the scientific journal Nature, and presented at the 235th meeting of the American Astronomical Society, has pinpointed the origin of an FRB to an unexpected environment in a nearby spiral galaxy. Observations with the Gemini North telescope of NSF’s Optical-Infrared Astronomy Research Laboratory (OIR Lab) on Maunakea in Hawai‘i, played a vital role in this discovery, which renders the nature of these extragalactic radio pulses even more enigmatic.

The sources of FRBs and their nature are mysterious — many are one-off bursts but very few of them emit repeated flashes. The recently discovered FRB — identified by the unpoetic designation FRB 180916.J0158+65 — is one of only five sources with a precisely known location and only the second such source that shows repeated bursts. Such FRB’s are referred to as localized and can be associated with a particular distant galaxy, allowing astronomers to make additional observations that can provide insights into the origin of the radio pulse.

“This object’s location is radically different from that of not only the previously located repeating FRB, but also all previously studied FRBs,” elaborates Kenzie Nimmo, PhD student at the University of Amsterdam and a fellow lead author of this paper. “This blurs the differences between repeating and non-repeating fast radio bursts. It may be that FRBs are produced in a large zoo of locations across the Universe and just require some specific conditions to be visible.”

Pinpointing the location of FRB 180916.J0158+65 required observations at both radio and optical wavelengths. FRBs can only be detected with radio telescopes, so radio observations are fundamentally necessary to accurately determine the position of an FRB on the sky. This particular FRB was first discovered by the Canadian CHIME radio telescope array in 2018[1]. The new research used the European VLBI Network (EVN)[2] to precisely localize the source, but measuring the precise distance and local environment of the radio source was only possible with follow-up optical observations with the Gemini North telescope. The international Gemini Observatory comprises telescopes in both the northern and southern hemispheres, which together can access the entire night sky.

“We used the cameras and spectrographs on the Gemini North telescope to image the faint structures of the host galaxy where the FRB resides, measure its distance, and analyze its chemical composition,” explains Shriharsh Tendulkar, a postdoctoral fellow at McGill University in Montreal, Canada who led the Gemini observations[3] and subsequent data analysis. “These observations showed that the FRB originates in a spiral arm of the galaxy, in a region which is rapidly forming stars.”

However, the source of FRB 180916.J0158+65 — which lies roughly 500 million light-years from Earth — was unexpected and shows that FRB’s may not be linked to a particular type of galaxy or environment, deepening this astronomical mystery[4].

“This is the closest FRB to Earth ever localised,” explains Benito Marcote, of the Joint Institute for VLBI European Research Infrastructure Consortium and a lead author of the Nature paper. “Surprisingly, it was found in an environment radically different from that of the previous four localised FRBs — an environment that challenges our ideas of what the source of these bursts could be.”

The researchers hope that further studies will reveal the conditions that result in the production of these mysterious transient radio pulses, and address some of the many unanswered questions they pose. Corresponding author Jason Hessels of the Netherlands Institute for Radio Astronomy (ASTRON) and the University of Amsterdam states that “our aim is to precisely localize more FRBs and, ultimately, understand their origin.”

“It’s a pleasure to see different observing facilities complement one another during challenging high-priority investigations such as this,” concludes Luc Simard, Gemini Board member and Director General of NRC-Herzberg, which hosts CHIME, as well as the Canadian Gemini Office. “We are particularly honored to have the opportunity to conduct astronomical observations on Maunakea in Hawai’i. This site’s exceptional observing conditions are vital to making astronomical discoveries such as this.”

Chris Davis, National Science Foundation Program Officer for Gemini adds, “understanding the origin of FRBs will undoubtedly be an exciting challenge for astronomers in the 2020s; we’re confident that Gemini will play an important role, and it seems fitting that Gemini has made these important observations at the dawn of the new decade.”



Notes

[1] The Canadian Hydrogen Intensity Mapping Experiment (CHIME) collaboration operates an innovative radio telescope at the Dominion Radio Astrophysical Observatory in Canada. The CHIME telescope’s novel construction makes it particularly adept at discovering FRBs such as FRB 180916.J0158+65.

[2] Radio observations were made using eight radio telescopes of the European Very Long Baseline Interferometry Network (EVN) following the discovery of FRB 180916.J0158+65 by the CHIME/FRB Collaboration.

[3] The Gemini observations were made between July and September of 2019 using the Gemini Multi-Object Spectrograph (GMOS) on the Gemini North telescope on Hawaii’s Maunakea.

[4] Prior to the observations announced today, the evidence hinted at the possibility that repeating and non-repeating FRBs were formed in very different environments. The only repeating FRB apart from FRB 180916.J0158+65 with a precisely determined location was found to inhabit a region of massive star formation inside a dwarf galaxy. Conversely, the three localized non-repeating FRBs were all found in massive galaxies and appear not to be associated with star-forming regions, leading to speculation that there were two separate types of FRB.



More information

This research was presented in a paper in Nature entitled “A repeating fast radio burst source localized to a nearby spiral galaxy”.

NSF’s National Optical-Infrared Astronomy Research Laboratory, the US center for ground-based optical-infrared astronomy, operates the Gemini Observatory (a facility of NSF, NRC–Canada, CONICYT–Chile, MCTI–Brazil, MCTIP–Argentina, and KASI–Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and the Large Synoptic Survey Telescope (LSST, a facility that will be jointly operated by NSF and DOE). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai’i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O’odham Nation, to the Native Hawaiian community, and to the local Communities in Chile, respectively.



Contacts:
 
Peter Michaud
NewsTeam Manager
NSF’s National Optical-Infrared Astronomy Research Laboratory
Gemini Observatory, Hilo HI
Desk:: +1 808-974-2510
Cell: +1 808-936-6643
Email: pmichaud@gemini.edu

Jason Hessels
University of Amsterdam & ASTRON
Email: j.w.t.hessels@uva.nl
Phone: +31 610260062
Shriharsh Tendulkar
McGill University
Email: shriharsh@physics.mcgill.ca





* This article was originally published here

Astronomers witness the dragging of space-time in stellar cosmic dance


An international team of astrophysicists led by Australian Professor Matthew Bailes, from the ARC Centre of Excellence of Gravitational Wave Discovery (OzGrav), has shown exciting new evidence for 'frame-dragging'--how the spinning of a celestial body twists space and time--after tracking the orbit of an exotic stellar pair for almost two decades. The data, which is further evidence for Einstein's theory of General Relativity, is published in the journal Science.

Astronomers witness the dragging of space-time in stellar cosmic dance
Artist's depiction of 'frame-dragging': two spinning stars twisting space and time
[Credit: Mark Myers, OzGrav ARC Centre of Excellence]
More than a century ago, Albert Einstein published his iconic theory of General Relativity - that the force of gravity arises from the curvature of space and time and that objects, such as the Sun and the Earth, change this geometry. Advances in instrumentation have led to a flood of recent (Nobel prize-winning) science from phenomena further afield linked to General Relativity. The discovery of gravitational waves was announced in 2016; the first image of a black hole shadow and stars orbiting the supermassive black hole at the centre of our own galaxy was published just last year.

Almost twenty years ago, a team led by Swinburne University of Technology's Professor Bailes--director of the ARC Centre of Excellence in Gravitational Wave Discovery (OzGrav)--started observing two stars rotating around each other at astonishing speeds with the CSIRO Parkes 64-metre radio telescope. One is a white dwarf, the size of the Earth but 300,000 times its density; the other is a neutron star which, while only 20 kilometres in diameter, is about 100 billion times the density of the Earth. The system, which was discovered at Parkes, is a relativistic-wonder system that goes by the name 'PSR J1141-6545'.


Before the star blew up (becoming a neutron star), a million or so years ago, it began to swell up discarding its outer core which fell onto the white dwarf nearby. This falling debris made the white dwarf spin faster and faster, until its day was only measured in terms of minutes.

In 1918 (three years after Einstein published his Theory), Austrian mathematicians Josef Lense and Hans Thirring realised that if Einstein was right all rotating bodies should 'drag' the very fabric of space time around with them. In everyday life, the effect is miniscule and almost undetectable. Earlier this century, the first experimental evidence for this effect was seen in gyroscopes orbiting the Earth, whose orientation was dragged in the direction of the Earth's spin. A rapidly spinning white dwarf, like the one in PSR J1141-6545, drags space-time 100 million times as strongly!

A pulsar in orbit around such a white dwarf presents a unique opportunity to explore Einstein's theory in a new ultra-relativistic regime.

Astronomers witness the dragging of space-time in stellar cosmic dance
Artist's depiction of a rapidly spinning neutron star and a white dwarf dragging the fabric of space time
around its orbit [Credit: Mark Myers, OzGrav ARC Centre of Excellence]
Lead author of the current study, Dr Vivek Venkatraman Krishnan (from Max Planck Institute for Radio Astronomy - MPIfR) was given the unenviable task of untangling all of the competing relativistic effects at play in the system as part of his PhD at Swinburne University of Technology. He noticed that unless he allowed for a gradual change in the orientation of the plane of the orbit, General Relativity made no sense.

MPIfR's Dr Paulo Friere realised that frame-dragging of the entire orbit could explain their tilting orbit and the team presents compelling evidence in support of this in today's journal article--it shows that General Relativity is alive and well, exhibiting yet another of its many predictions.


The result is especially pleasing for team members Bailes, Willem van Straten (Auckland University of Tech) and Ramesh Bhat (ICRAR-Curtin) who have been trekking out to the Parkes 64m telescope since the early 2000s, patiently mapping the orbit with the ultimate aim of studying Einstein's Universe. 'This makes all the late nights and early mornings worthwhile', said Bhat.

Lead author Vivek Venkatraman Krishnan, Max Planck Institute for Radio Astronomy (MPIfR): 'At first, the stellar pair appeared to exhibit many of the classic effects that Einstein's theory predicted. We then noticed a gradual change in the orientation of the plane of the orbit.'

'Pulsars are cosmic clocks. Their high rotational stability means that any deviations to the expected arrival time of its pulses is probably due to the pulsar's motion or due to the electrons and magnetic fields that the pulses encounter.' 'Pulsar timing is a powerful technique where we use atomic clocks at radio telescopes to estimate the arrival time of the pulses from the pulsar to very high precision. The motion of the pulsar in its orbit modulates the arrival time, thereby enabling its measurement.'


Dr Paulo Freire: 'We postulated that this might be, at least in-part, due to the so-called "frame-dragging" that all matter is subject to in the presence of a rotating body as predicted by the Austrian mathematicians Lense and Thirring in 1918.'

Professor Thomas Tauris, Aarhus University: 'In a stellar pair, the first star to collapse is often rapidly rotating due to subsequent mass transfer from its companion. Tauris's simulations helped quantify the magnitude of the white dwarf's spin. In this system the entire orbit is being dragged around by the white dwarf's spin, which is misaligned with the orbit.'


Dr Norbert Wex, Max Planck Institute for Radio Astronomy (MPIfR): 'One of the first confirmations of frame-dragging used four gyroscopes in a satellite in orbit around the Earth, but in our system the effects are 100 million times stronger.'

Evan Keane (SKA Organisation): 'Pulsars are super clocks in space. Super clocks in strong gravitational fields are Einstein's dream laboratories. We have been studying one of the most unusual of these in this binary star system. Treating the periodic pulses of light from the pulsar like the ticks of a clock we can see and disentangle many gravitational effects as they change the orbital configuration, and the arrival time of the clock-tick pulses. In this case we have seen Lens-Thirring precession, a prediction of General Relativity, for the first time in any stellar system.'

From Willem van Straten (AUT): 'After ruling out a range of potential experimental errors, we started to suspect that the interaction between the white dwarf and neutron star was not as simple as had been assumed to date.'

Source: Swinburne University of Technology [January 30, 2020]



* This article was originally published here

Understanding long-term trends in ocean layering


Water layering is intensifying significantly in about 40% of the world's oceans, which could have an impact on the marine food chain. The finding, published in the Journal of Geophysical Research: Oceans, could be linked to global warming.

Understanding long-term trends in ocean layering
Credit: Tohoku University
Tohoku University geophysicist Toshio Suga collaborated with climate physicist Ryohei Yamaguchi of Korea's Pusan National University to investigate how upper-ocean stratification has changed over a period of 60 years.

Upper-ocean stratification is the presence of water layers of varying densities scattered between the ocean's surface and a depth of 200 metres. Density describes how tightly water is packed within a given volume and is affected by water temperature, salinity and depth. More dense water layers lie beneath less dense ones.


Ocean water density plays a vital role in ocean currents, heat circulation, and in bringing vital nutrients to the surface from deeper waters. The more significant the stratification in the upper ocean, the larger the barrier between the relatively warm, nutrient-depleted surface, and the relatively cool, nutrient-rich, deeper waters. More intense stratification could mean that microscopic photosynthetic organisms called phytoplankton that live near the ocean's surface won't get the nutrients they need to survive, affecting the rest of the marine food chain.

Understanding long-term trends in ocean layering
Upper ocean stratification has been strengthening in a large part of the global ocean since the 1960s.
Colour shows trends in density difference between the surface and 200-m depth
(unit: kg m-3/decade) [Credit: Ryohei Yamaguchi]
Scientists think that global warming could be increasing upper ocean stratification, but investigations have been limited and have usually used short-term data, leading to a large degree of uncertainty. Suga and Yamaguchi compiled temperature and salinity data from the World Ocean Database 2013, covering the period from 1960 to 2017. They then used mathematical equations to calculate the difference in temperature and salinity content between 10 and 200 metres in the regions where data was available.


They found that around 40% of the world's oceans are witnessing a rise in upper ocean density stratification. Half of this rise is happening in tropical waters. They also found that rising stratification in mid-latitude and high-latitude oceans of the Northern Hemisphere varied seasonally, with faster changes happening in the summer compared to winter months.

Additionally, inter-annual variations in several regions correlated with climatic events, such as the Pacific Decadal Oscillation, the North Atlantic Oscillation and El Nino. This suggests that changes in density stratification could be a key factor explaining how large-scale atmospheric changes impact biogeochemical processes, the researchers say.

Suga and Yamaguchi note further studies are needed to confirm this link. But for this to happen, continued international corroborative efforts are needed to gather global, long-term temperature and salinity data across various upper-ocean depths.

Source: Tohoku University [January 30, 2020]



* This article was originally published here

DNA extracted in museum samples can reveal genetic secrets


DNA in preserved museum specimens can allow scientists to explore the history of species and humanities impact on the ecosystem, but samples are typically preserved in formaldehyde which can damage DNA and make very difficult to recover.

DNA extracted in museum samples can reveal genetic secrets
The protocol begins with Vortex Fluidic Device (VFD) treatment of a mixture of proteinase K and the frozen, then
broken-up tissue. The reaction mixture is next processed to remove solids and DNA polymerase inhibitors.
The recovered DNA is then purified and concentrated. Finally, the DNA is amplified, quantified,
 and characterized by (B) qPCR and (C) DNA sequencing of the samples
[Credit: Christian A. Totoiu et al., 2020]
Researchers have used a vortex fluidic device (VFD) to speed up DNA extraction from an American lobster preserved in formaldehyde - with the results providing a roadmap for exploring DNA from millions of valuable and even extinct species in museums worldwide.

Flinders PHD candidate Jessica Phillips says processing the preserved tissue from museum specimens in the VFD breaks apart proteins, releasing DNA which offers important historical genetic information.

"DNA extraction is achieved by processing the preserved tissue in an enzyme solution in the VFD. This enzyme breaks apart the proteins, releasing the DNA which can be analysed. By using the VFD we are able to accelerate this process from days to hours," says Ms Phillips.

"For 150 years these samples have been preserved in formaldehyde which can damage the DNA and also make DNA difficult to recover. We used mechanical energy in a vortex fluidic device (VFD) to accelerate the extraction by processing the preserved tissue in an enzyme solution in the VFD."


This work is a collaboration between University of California, Irvine (UCI), The Department of Organismic and Evolutionary Biology at Harvard University, and Flinders University.

Researchers say the results provide a roadmap for exploring DNA from millions of historical and even extinct species in museums worldwide.

Research Chair of Clean Technology Research Professor Colin Raston says the work builds on the body of about 80 papers that his research group has published about the vortex fluidic device.

"Applications of the VFD are rapidly expanding, but this has only been possibly by internal collaboration. The DNA extraction application involved collaboration with two other research laboratories headed by Professor Greg Weiss at UCI and Professor Peter Girguis at Harvard."

"We have only scratched the surface about what is possible for this device," says Professor Raston."

The study is published in PLOS ONE.

Author: Yaz Dedovic | Source: Flinders University [January 31, 2020]



* This article was originally published here

Featured

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

Popular