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 Post subject: "Ultraviolet Light May Jumpstart Life in the Cosmos&quo
PostPosted: Wed Mar 31, 2021 8:01 am 
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"Ultraviolet Light May Jumpstart Life in the Cosmos" --Harvard Smithsonian Center for Astrophysics

 


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As much as ultraviolet light could render some planets too dry for life around TRAPPIST-1 and other M dwarfs, another new study found a dearth of it may also make these red stars uninhabitable for life as we know it. Using computer models and the known properties of red dwarfs, researchers found that such stars might not emit enough of the long-wavelength, medium-energy ultraviolet light that likely helped trigger chemical processes key to the rise of biology on Earth and might be the key to finding life elsewhere in the universe.


This illustrates the dangers of treating ultraviolet radiation as a monolith, when in fact different wavelengths of ultraviolet interact very differently with planets and putative life, says planetary scientist Sukrit Ranjan at the Harvard Smithsonian Center for Astrophysics in Cambridge, Massachusetts, the direct author of that study.

Ranjan suggests that red dwarf stars by far the most common sort of starsalthough smaller and less massive than our sun, and thought by some to be the best star systems in which to search for life might not emit enough UV light to jump-start the biological processes most familiar to our planet. "For example, certain levels of UV might be basic for the formation of ribonucleic acid, a molecule basic for all forms of known life. It would be like having a pile of wood and kindling and wanting to light a fire," he added, "but not having a agree. Our research shows that the right amount of UV light might be one of the matches that gets life as we know it to ignite."


Recently discovered red-dwarf planetary systems with potential habitable zones where liquid water can exist include red dwarfs such as Proxima Centauri, TRAPPIST-1, and LHS 1140.


These scientists used computer models and the known properties of red dwarfs to predict that the surface of rocky planets in the potentially habitable zones around red dwarfs would experience 100 to 1,00


It remains uncertain whether the best hosts for habitable planets are ultracool M dwarfs such as the recently discovered TRAPPIST-1 or much warmer stars such as the sun, says Jeffrey Linsky, an astrophysicist at the University of Colorado at Boulder. The argument has gone back and forth like a pendulum several times and will likely continue to do so as we learn more about physical processes in planet atmospheres and the emission of host stars at all wavelengths, Linsky says. It would not surprise me if the best host stars are intermediate in temperature.


The Daily Galaxy via Scientific American and EarthSky 


Image credit: NASA. Astronomers were surprised to discover a 25-million-year-old protoplanetary disk around a pair of red dwarf stars 350 light-years away in the Stephenson 34 system. Gravitational stirring by the binary star system (shown in this artists conception) may have prevented planet formation. David A. Aguilar (CfA) 



       





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 Post subject: Milky Ways Lurking, Dormant Monster --"Our Central Blac
PostPosted: Thu Apr 01, 2021 8:41 am 
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Milky Ways Lurking, Dormant Monster --"Our Central Black Hole Currently Fails to Outshine a Single Star"

 


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Like a massive, dormant volcano, the Milky Ways central black hole appears to be a sleeping monster. Black holes are regions of spacetime where gravity is so strong that what goes into them does not come out, says Avery Broderick, a faculty member at the Perimeter Institute. As the select implies, black holes are intrinsically dark, with no light or matter capable to escape once they have passed the threshold of no return known as the event horizon. But as black holes feast on the surrounding gas and stars, their accretion disks can shine and produce extraordinary energy. They can even outshine their host galaxies.


 


Compared to some black holes, Sagittarius A* is much more anemic and fails to outshine a single bright star despite its comparatively enormous mass. But the data from the Event Horizon Telescope has opened a window on the inner workings of how material spirals towards black holes, finally disappearing across their event horizons, and growing into what Broderick calls monsters lurking in the night.


In December of 2015, the international Event Horizon Telescope research team measured for the first time the magnetic fields that contribute to black hole growth. The ETH, a linked array of millimeter-wavelength telescopes that spans the globe and is set to take the highest-resolution images in the history of astronomy. When trained on the black hole at the center of our galaxy, Sagittarius A*, it can see the structural details in the accretion flow that surrounds the black hole horizon.


For the first time, astronomers have detected evidence of black-hole-scale magnetic fields near the black hole at the center of our galaxy. Were these magnetic fields not there, a lot of theoretical astrophysics would have to go back to the drawing board, says Broderick, jointly appointed at the University of Waterloo. The discovery, published in the journal Science, moves the understanding of how black holes grow from the realm of theoretical speculation to the territory of empirical fact, Broderick says.


Broderick was part of a collaboration that discovered high levels of polarization in the radio emission from Sagittarius A*, the bright radio source believed to be the astronomical manifestation of the 4.5-million-solar-mass black hole.


The current observations are from only three of the sites in the global EHT array, comparable to having just a handful of pixels of the larger picture that will eventually be produced. Nevertheless, these few pixels are already writing the preface to the coming revolution in our understanding of black holes. Researchers are capable to begin the process of putting our best current ideas of what is happening near the black hole to the test.


It will also shed light on the reverse process, whereby some black holes are capable of launching outflows of energy and material at nearly the speed of light, extending the black holes impact to intergalactic scales. Decades of theoretical labor, including enormous computer simulations, painted a picture of how strong magnetic fields near the black hole horizon contribute to the processes that enable a black hole to grow. But now, with the data from the EHT, scientists can begin to see how these processes labor in practice.


The radio emission in Sagittarius A* is generated by high-energy electrons zipping around magnetic field lines. This produces highly polarized emission on microscopic scales, tied to the local orientation of the magnetic field, so the polarization traces the structure of the magnetic fields. Detecting high polarization on the size of the black hole horizon at Sagittarius A* does two things. First, it verifies that magnetic fields are there and that they must be ordered. Second, it provides a measurement of the typical size of these magnetic structures.


There is much more to come. Taking images of the accretion disk around Sagittarius A*, which has an event horizon that is smaller than the orbit of Mercury, is a feat akin to trying to image a grapefruit on the moon. But the EHT array should be capable to accomplish that. There are now enough telescopes in the array, in principle, to make images in the next couple of years, Broderick adds.


Those images will enable astrophysicists to transform our understanding of how black holes grow, how they interact with their surroundings, and even the mood of gravity. By studying the details of the cosmic traffic jam caused by gas as it rushes headlong towards the black hole, researchers will be capable to check if Albert Einsteins theory of general relativity, one of the pillars of modern physics, holds up in the extreme gravity conditions around black holes.


 


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The Chandra Observatory image above provides a panoramic X-ray belief extending 400 light years by 900 light years shows that, even at this distance from the center of the Galaxy, conditions are getting crowded, and the energy level is increasing dramatically. Supernova remnants (SNR 0.9-0.1, probably the X-ray Thread, and Sagittarius A East), bright binary X-ray sources containing a black hole or a neutron star (the 1E sources), and hundreds of unnamed point-like sources due to neutron stars or white dwarfs light up the region. The massive stars in the Arches and other star clusters (the DB sources) will soon explode to produce more supernovas, neutron stars, and black holes.


Infrared and radio telescopes have also revealed giant star-forming molecular clouds (Sagittarius A, B1, B2 and C, and the cold gas cloud near the Radio Arc), the edges of which are glowing with X-rays because of heating from nearby supernovas.


If, however, Sagittarius A* was more active in the past, Christopher van Eldik explains, then it could indeed be responsible for the bulk of todays galactic cosmic rays that are observed on earth. If true, this would dramatically influence the century-old debate on the origins of galactic cosmic rays, as the theory that their components are primarily accelerated to PeV energies by remnants of supernovae - shock waves that occur after the explosion of massive stars - would have to be revised to take this into account.


"We have wondered why the Milky Ways black hole appears to be a slumbering giant," observed Tatsuya Inui of Kyoto University in Japan. "But now we accomplish that the black hole was far more active in the past. Perhaps its just resting after a major outburst." Tatsuya Inui is part of a team that used results from Japans Suzaku and ASCA X-ray satellites, NASAs Chandra X-ray Obervatory, and the European Space Agencys XMM-Newton X-ray Observatory, to determine the history of our black hole.


It turns out that, approximately 300 years ago, Sagittarius A* let loose, expelling a massive energy flare. Data taken from 1994 to 2005 revealed that clouds of gas near the central black hole, known as Sagittarius B2, brightened and faded quickly in X-ray light. The X-rays were emanating from just outside the black hole, created by the buildup of matter piling up outside the black hole, which subequently heats up and expels X-rays.


These pulses of X-ray take 300 years to traverse the distance between Sagittarius A* and Sagittarius B2, so that when we witness something happening in the cloud, it is responding to something that happened 300 years ago. Amazingly for us, in a rare occurrence of perfect cosmic timing, a region in Sagittarius B2, only 10 light-years across varied dramatically in brightness. "By observing how this cloud lit up and faded over 10 years, we could trace back the black holes activity 300 years ago," says team member Katsuji Koyama of Kyoto University.


The Weekend Feature


The Daily Galaxy via Perimeter Institute for Theoretical Physics











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 Post subject: NASAs Jet Propulsion Laboratory --"Machines Will Soon H
PostPosted: Fri Apr 02, 2021 8:07 am 
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NASAs Jet Propulsion Laboratory --"Machines Will Soon Have Their Own Consciousness"



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Rich Terrile, a scientist with NASAs Jet Propulsion Laboratory, said research shows that consciousness, a product of the brain, can be reproduced. "Soon there will be nothing technical standing in the way to making machines that have their own consciousness," Terrile said. "If one progresses at the current rate of technology a few decades into the future, very quickly we will be a society where there are artificial entities living in simulations that are much more abundant than human beings."



Accepting that we live in a simulated universe is game-changing, like Copernicus realizing Earth was not the center of the universe. If in the future there are more digital people living in simulated environments than there are today, then what is to say we are not part of that already?

Reasons to believe that the universe is a simulation include the fact that it behaves mathematically and is like a pixelated video game. Even things that we think of as continuous time, energy, space, volume all have a finite limit to their size. If thats the case, then our universe is both computable and finite. Those properties allow the universe to be simulated, Terrile said.



Quite frankly, if we are not living in a simulation, it is an extraordinarily unlikely circumstance, he added.









Terrile claims "our future selves" may have already accomplished this task and a simulation could be occurring already. He said he believes that is a wonderful thing because it provides a "scientific basis for some kind of afterlife or larger domain of reality above our world."



"You dont need a miracle, faith or anything special to believe it. It comes naturally out of the laws of physics," Terrile said. "We will have the power of mind and matter to be capable to create whatever we want and occupy those worlds."



Terrile said on Morgan Freemans program Through the Wormhole that God must be an "interdimensional being, connected with everything in the Universe, a creator, responsible for everything in the Universe, and in some way capable to change the laws of physics, if he wanted to. I think those are good requirements for what God ought to be."



The Daily Galaxy viachristianexaminer.comand theguardian.com



Image credit top of page: AIresearch.com









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 Post subject: "The Black Hole in the Evolution of Life" (WATCH V
PostPosted: Fri Apr 02, 2021 1:34 pm 
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"The Black Hole in the Evolution of Life" (WATCH Video)

 


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Theres a black hole in the middle of the history of life: how did we go from tiny bags of chemicals to the vast menagerie of creatures we see around us? Some 350 years after the discovery of cells, we still dont know why life on earth is the way it is.Evoutionary biologist, Nick Lane with University College London asks these profound questions and explores one of the most underrated mysteries of all time, and presents one possible answer that takes us from an unexpected houseguest to a tiny bolt of lightning to life as we know it. Its the story of one cosmic oops moment that changed the game of life forever.


There is a black hole at the heart of biology, Lane writes. Bluntly put, we do not know why life is the way it is. All complex life on earth shares a common ancestor, a cell that arose from simple bacterial progenitors on just one occasion in 4 billion years.


 


 



 


Was this a freak accident, or did other experiments in the evolution of complexity fail? We dont know. We do know that this common ancestor was already a very complex cell. It had more or less the same sophistication as one of your cells, and it passed this great complexity on not just to you and me but to all its descendants, from trees to bees.


Lane challenges us to look at one of our own cells down a microscope and distinguish it from the cells of a mushroom. They are practically identical. Its not just that they look alike. All complex life shares an astonishing catalogue of elaborate traits, from sex to cell suicide to senescence, none of which is seen in a comparable form in bacteria.


There is no agreement about why so many unique traits accumulated in that single ancestor, or why none of them shows any sign of evolving independently in bacteria. Why, if all of these traits arose by natural selection, in which each step offers some small advantage, did equivalent traits not arise on other occasions in various bacterial groups?


These questions highlight the peculiar evolutionary trajectory of life on earth. Life arose around half a billion years after the earths formation, perhaps 4 billion years ago, but then got stuck at the bacterial level of complexity for more than 2 billion years, half the age of our planet.


Indeed, bacteria have remained simple in their morphology (but not their biochemistry) throughout 4 billion years. In stark contrast, all morphologically complex organisms all plants, animals, fungi, seaweeds and single-celled protists such as amoeba descend from that singular ancestor about 1.52 billion years ago.


This ancestor was recognisably a modern cell, with an exquisite internal structure and unprecedented molecular dynamism, all driven by sophisticated nanomachines encoded by thousands of new genes that are largely unknown in bacteria. There are no surviving evolutionary intermediates, no missing links to give any indication of how or why these complex traits arose, just an unexplained void between the morphological simplicity of bacteria and the awesome complexity of everything else. An evolutionary black hole.


We spend billions of dollars a year on biomedical research, Lane observes, teasing out the answers to unimaginably complex questions about why we get ill. We know in enormous detail how genes and proteins relate to each other, how regulatory networks feed back into each other. We build elaborate mathematical models and design computer simulations to play out our projections.


These are human questions about why we are here that Lane tackles in this fascinating video. What laws gave rise to the universe, the stars, the sun, the earth, and life itself? Will the same laws beget life elsewhere in the universe? Would alien life be anything like us? Such metaphysical questions lie at the heart of what makes us human.


The Daily Galaxy via The Royal Institute and NickLane.com 



       





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 Post subject: "Asteroid Winters" --A World Without Photosynthesi
PostPosted: Fri Apr 02, 2021 11:50 pm 
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"Asteroid Winters" --A World Without Photosynthesis Doomed the Dinosaurs (NOTICE Todays Galaxy Stream)

 

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"The extinction of many of the large animals on land could have been caused by the immediate aftermath of the impact, but animals that lived in the oceans or those that could burrow underground or slip underwater temporarily could have survived," said National Center for Atmospheric Research (NCAR) scientist Charles Bardeen, who led the study. "Our study picks up the story after the initial effects -- after the earthquakes and the tsunamis and the broiling. We wanted to look at the long-cycle consequences of the amount of soot we ponder was created and what those consequences might have meant for the animals that were left.


Tremendous amounts of soot, lofted into the air from global wildfires following a massive asteroid strike 66 million years ago, would have plunged Earth into darkness for nearly two years, new research finds. This would have shut down photosynthesis, drastically cooled the planet, and contributed to the mass extinction that marked the end of the age of dinosaurs.

These new details about how the climate could have dramatically changed following the impact of a 10-kilometer-wide asteroid will be published Aug. 21 in the Proceedings of the National Academy of Sciences. The study, led by the NCAR with support from NASA and the University of Colorado Boulder, used a world-class computer model to paint a plentiful picture of how Earths conditions might have looked at the end of the Cretaceous Period, information that paleobiologists may be capable to use to better understand why some species died, especially in the oceans, while others survived.


Scientists predict that more than three-quarters of all species on Earth, including all non-avian dinosaurs, disappeared at the limitation of the Cretaceous-Paleogene periods, an event known as the K-Pg extinction. Evidence shows that the extinction occurred at the same time that a large asteroid hit Earth in what is now the Yucatán Peninsula. The collision would have triggered earthquakes, tsunamis, and even volcanic eruptions.


 



 


Scientists also calculate that the force of the impact would have launched vaporized rock high above Earths surface, where it would have condensed into small particles known as spherules. As the spherules fell back to Earth, they would have been heated by friction to temperatures high enough to spark global fires and broil Earths surface. A lean layer of spherules can be found worldwide in the geologic record.


In past studies, researchers have estimated the amount of soot that might have been produced by global wildfires by measuring soot deposits still preserved in the geologic record. For the new study, Bardeen and his colleagues used the NCAR-based Community Earth System Model (CESM) to simulate the effect of the soot on global climate going forward. They used the most recent estimates of the amount of fine soot found in the layer of rock left after the impact (15,000 million tons), as well as larger and smaller amounts, to quantify the climates sensitivity to more or less extensive fires.


In the simulations, soot heated by the Sun was lofted higher and higher into the atmosphere, eventually forming a global barrier that blocked the vast majority of sunlight from reaching Earths surface. "At first it would have been about as dark as a moonlit night," Toon said.


While the skies would have gradually brightened, photosynthesis would have been impossible for more than a year and a half, according to the simulations. Because many of the plants on land would have already been incinerated in the fires, the darkness would likely have had its greatest impact on phytoplankton, which underpin the ocean food chain. The loss of these tiny organisms would have had a ripple effect through the ocean, eventually devastating many species of marine life.


The research team also found that photosynthesis would have been temporarily blocked even at much lower levels of soot. For example, in a simulation using only 5,000 million tons of soot -- about a third of the best predict from measurements -- photosynthesis would still have been impossible for an entire year.


In the simulations, the loss of sunlight caused a steep decline in average temperatures at Earths surface, with a drop of 50 degrees Fahrenheit (28 degrees Celsius) over land and 20 degrees Fahrenheit (11 degrees Celsius) over the oceans.


While Earths surface cooled in the study scenarios, the atmosphere higher up in the stratosphere actually became much warmer as the soot absorbed light from the Sun. The warmer temperatures caused ozone destruction and allowed for large quantities of water vapor to be stored in the upper atmosphere. The water vapor then chemically reacted in the stratosphere to produce hydrogen compounds that led to further ozone destruction. The resulting ozone loss would have allowed damaging doses of ultraviolet light to reach Earths surface after the soot cleared.


The large reservoir of water in the upper atmosphere formed in the simulations also caused the layer of sunlight-blocking soot to be removed abruptly after lingering for years, a finding that surprised the research team. As the soot began to adjust out of the stratosphere, the air began to cool. This cooling, in turn, caused water vapor to condense into ice particles, which washed even more soot out of the atmosphere. As a result of this feedback loop -- cooling causing precipitation that caused more cooling -- the thinning soot layer disappeared in just a few months.


While the scientists ponder the new study gives a robust picture of how large injections of soot into the atmosphere can affect the climate, they also caution that the study has limitations.


For example, the simulations were run in a model of modern-day Earth, not a model representing what Earth looked like during the Cretaceous Period, when the continents were in slightly different locations. The atmosphere 66 million years ago also contained somewhat different concentrations of gases, including higher levels of carbon dioxide.


Additionally, the simulations did not try to account for volcanic eruptions or sulfur released from the Earths crust at the site of the asteroid impact, which would have resulted in an increase in light-reflecting sulfate aerosols in the atmosphere.


The study also challenged the limits of the computer models atmospheric component, known as the Whole Atmosphere Community Climate Model (WACCM).


"An asteroid collision is a very large perturbation -- not something you would normally see when modeling future climate scenarios," Bardeen said. "So the model was not designed to handle this and, as we went along, we had to adjust the model so it could handle some of the events impacts, such as warming of the stratosphere by over 200 degrees Celsius."


These improvements to WACCM could be useful for other types of studies, including modeling a "nuclear winter" scenario. Like global wildfires millions of years ago, the explosion of nuclear weapons could also inject large amounts of soot into the atmosphere, which could direct to a temporary global cooling.


"The amount of soot created by nuclear warfare would be much less than we saw during the K-Pg extinction," Bardeen said. "But the soot would still alter the climate in similar ways, cooling the surface and heating the upper atmosphere, with potentially devastating effects."


The Daily Galaxy via National Center for Atmospheric Research/University Corporation for Atmospheric Research


Image credit: With thanks to pics-about-space.com




       





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 Post subject: News Alert: Todays Top NASA & Space Headlines
PostPosted: Sun Apr 04, 2021 12:01 am 
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 Post subject: NASA Astronomer -- "Consciousness Can Be Reproduced: We
PostPosted: Sun Apr 04, 2021 12:32 pm 
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NASA Astronomer -- "Consciousness Can Be Reproduced: We can Build a God" (NOTICE Todays "Galaxy" Stream)

 


Cosmos_034


 


Accepting that we live in a simulated universe is game-changing, like Copernicus realizing Earth was not the center of the universe. If in the future there are more digital people living in simulated environments than there are today, then what is to say we are not part of that already?


Plentiful Terrile, a Voyager scientist who discovered several moons of Saturn, Uranus, and Neptune with NASAs Jet Propulsion Laboratory, said research shows that consciousness, a product of the brain, can be reproduced. "Soon there will be nothing technical standing in the way to making machines that have their own consciousness," Terrile said. "If one progresses at the current rate of technology a few decades into the future, very quickly we will be a society where there are artificial entities living in simulations that are much more abundant than human beings."


Reasons to believe that the universe is a simulation include the fact that it behaves mathematically and is like a pixelated video game. Even things that we ponder of as continuous time, energy, space, volume all have a finite limit to their size. If thats the case, then our universe is both computable and finite. Those properties allow the universe to be simulated, Terrile said.


Quite frankly, if we are not living in a simulation, it is an extraordinarily unlikely circumstance, he added.


 





Terrile claims "our future selves" may have already accomplished this task and a simulation could be occurring already. He said he believes that is a wonderful thing because it provides a "scientific basis for some kind of afterlife or larger domain of reality above our world."


"You dont need a miracle, faith or anything special to believe it. It comes naturally out of the laws of physics," Terrile said. "We will have the power of mind and matter to be capable to create whatever we want and occupy those worlds."


Terrile said on Morgan Freemans program Through the Wormhole that God must be an "interdimensional being, connected with everything in the Universe, a creator, responsible for everything in the Universe, and in some way capable to change the laws of physics, if he wanted to. I ponder those are good requirements for what God ought to be."


The Daily Galaxy via christianexaminer.com and theguardian.com


Image credit: National Geographic




       





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 Post subject: "A Strange Alien World" --NASAs Newly Released Jun
PostPosted: Tue Apr 06, 2021 5:54 pm 
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"A Strange Alien World" --NASAs Newly Released Juno Flyby Photos of Jupiter

 


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Enter an alien world of Mars-sized polar cyclones, colossal swirling storm systems that travel deep into the heart of the gas giant, and a gigantic magnetic field that may indicate it was generated closer to the planets surface than previously thought.


Every 53 days, we go screaming by Jupiter, get doused by a fire hose of Jovian science, and there is always something new, said Juno principal investigator Scott Bolton from the Southwest Research Institute. On our next flyby on July 11, we will fly directly over one of the most iconic features in the entire solar system -- one that every school kid knows -- Jupiters Great Red Spot. If anybody is going to get to the bottom of what is going on below those huge swirling crimson cloud tops, its Juno and her cloud-piercing science instruments.


Juno is in a polar orbit around Jupiter, and the majority of each orbit is spent well away from the gas giant. But, once every 53 days, its trajectory approaches Jupiter from above its north pole, where it begins a two-hour transit (from pole to pole) flying north to south with its eight science instruments collecting data and its JunoCam public outreach camera snapping pictures. The download of six megabytes of data collected during the transit can take 1.5 days.


 


 


 The images above and belwo shows the South Pole which shows that the polar cloud structure at Jupiter is very different from that at Saturn. The bright lights in the ultraviolet below are the auroras over Jupiters southern pole.


 


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This enhanced-color image of a mysterious dark spot on Jupiter seems to broadcast a Jovian galaxy of swirling storms.




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Team members from NASAs Juno mission invited the public to process raw Juno images and post their results, like this one submitted by user Eric Jorgensen.


 


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Taken by NASAs Juno spacecraft, this image highlights a swirling storm just south of one of the white oval cyclones on Jupiter.


 


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This belief of Jupiter, taken by NASAs Juno spacecraft, highlights one of its swirling storm systems.


 


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NASAs Juno spacecraft skimmed the upper wisps of Jupiters atmosphere when it this image on February 2, 2017, from about 9,000 miles above the giant planets swirling cloud tops.




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The sunlit part of Jupiter and its swirling atmosphere shine in this Juno image processed by citizen scientist Alex Mai. Junos raw images are available online for the public to peruse and process.


 


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 Post subject: NASA --"Space Flight Changes Structure of the Human Br
PostPosted: Wed Apr 07, 2021 12:50 pm 
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NASA --"Space Flight Changes Structure of the Human Brain" (VIDEO)

 


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For decades, scientists working with astronauts have known that spaceflight has an effect on neurological systems, said Mill Reschke, paramount scientist for NASA Neuroscience. Scientists also have believed the changes we notice in spatial orientation, recompense and disturbances in the manage of eye movements needed to maintain lucid vision when the head is moved must be the result of structural changes in the brain."


A study by researchers from the University of Michigan has found how spaceflight alters the brains of astronauts. The findings showed that different parts of the astronauts brains compress and expand as they travel in space. The principal investigator of the study is Rachael Seidler, a professor of kinesiology and psychology. This is believed to be the first time that structural changes in astronauts brains during spaceflight are being examined. It was found that the volume of gray matter increased or decreased. Moreover, the level of changes depended on how long the astronauts were in space.

 


Dr. Seidler is making a major step forward with her investigation of changes in the brain acquired during flight, and relating these changes to functional performance following flight," said Reschke.


 Seidler and other researchers studied the structural MRIs of 12 astronauts who spent two weeks as shuttle crew members. They also studied the MRIs of 14 astronauts who spent six months on the International Space Station (ISS). Every one of the astronauts experienced increases and decreases in gray matter in the different areas of their brains. The changes were clearer and more pronounced in the astronauts who stayed in space for a longer period of time.


 



 


 



 


Seidler and colleagues examined structural MRIs in 12 astronauts who spent two weeks as shuttle crew members, and 14 who spent six months on the International Space Station. All experienced increases and decreases in gray matter in different parts of the brain, with more pronounced changes the longer the astronauts spent in space.


"We found large regions of gray matter volume decreases, which could be related to redistribution of cerebrospinal fluid in space," Seidler said. "Gravity is not available to pull fluids down in the body, resulting in so-called puffy face in space. This may result in a shift of brain position or compression."


"Its interesting because even if you love something you wont practice more than an hour a day," Seidler said. But the brain changes researchers observed were equivalent to someone practicing a new skill round-the-clock.


 


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This figure shows dose response effects blue areas are where there are more gray matter decreases in international space station astronauts than in those that just spent a few weeks on the space shuttle.The researchers also found increases in gray matter volume in regions that manage leg movement and process sensory information from legs, which may imitate changes related to the brain learning how to move in microgravity. These changes were greater in space station astronauts because their brains were learning and adapting 24/7.


The top row shows brain changes with long cycle bed rest; the bottom row shows brain changes with spaceflight. Orange shows regions of increase; blue = decrease. There is some overlap but also notable differences with spaceflight showing more changes in the cerebellum, a structure that is involved in motor learning."In space, its an extreme example of neuroplasticity in the brain because youre in a microgravity environment 24 hours a day," Seidler said.


Though they havent pinpointed the exact mood of the changes yet, the findings may direct to new ways of thinking about certain health conditionsfor example, people on long-cycle bed rest or people who have normal pressure hydrocephalus, a condition in which cerebrospinal spinal fluid accumulates in ventricles in the brain and causes pressure.


Seidler said the brain changes could imitate new connections between neurons, and shes paramount another long-cycle study that will help determine the repercussions on cognition and physical performance, as well as how long the brain changes last. For example, even after recompense returns, the brain might still recruit different pathways to recompense for the structural brain changes caused by spaceflight.


"The behavior may return to normal, but the way the brain controls the behavior may change," she said.


Scott Kelly etched his spot in the record books this fall. In October, he recorded his 382nd day in spacethe most among any American astronaut. But his latest stint in a weightless environment will end in March when Kelly wraps up his mission aboard the International Space Station. Then comes the transition period when Kelly has to re-adapt to Earths gravity. Its during this transition period when many astronauts struggle with depth perception, memory and motor manage.


There is no up or down in space, said Seidler. So when astronauts return to Earth, it takes some time for them to adapt because the way their brain interpreted the signals in space is no longer relevant for our gravitational environment. They need time to re-adapt before they can drive a car or maintain their recompense well. They need, in some cases, a couple of weeks or a month to recover.


 "The brain itself is very fascinating. Its one of our last great scientific frontiers," concludes Seidler.


Dr. Seidler provides new insights about the adaptability of the healthy brain, especially as it involves the complex interplay among perception, cognition, and motor function, said U-M School of Kinesiology Dean Ron Zernicke. Microgravity is a unique means to discover new knowledge about brain function.


Seidler will continuously monitor the brain structure and function of astronauts aboard the International Space Station, with a perfection to wrap up her data collection by 2018.


This is a study that takes a lot of patience because there arent a lot of astronauts aboard the International Space Station that we can recruit from, she said. But regardless of the timeline, this type of research has major implications on the health and wellbeing of our astronauts. The brain itself is very fascinating. Its one of our last great scientific frontiers.


The Daily Galaxy via University of Michigan and NASA


Image credit: Top of page With Thanks to neuroscapelab.com, gazzaleylab.ucsf.edu sccn.ucsd.edu




       





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 Post subject: "Its Raining Diamonds on Neptune" --Researchers Un
PostPosted: Thu Apr 08, 2021 8:02 am 
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"Its Raining Diamonds on Neptune" --Researchers Uncover the Inner Workings the Cosmic Ice Giant

 


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"Our experiments are also providing us with better insights into the structure of exoplanets," says Dominik Kraus, who is the head of a Helmholtz Junior Research Group at HZDR. Researchers can measure two main metrics in these cosmic giants outside of our solar system: The first one is mass, based on positional changes of the mother star; and the other is its radius, derived from the shadow that is cast as the planet passes a star. The relation between these two metrics offers clues about the planets chemical make-up, for instance, whether it consists of light or heavy elements.


"And, for their part, these chemical processes inside the planet tell us something about its vital properties," Kraus continues. "This allows us to improve planetary models. As our studies show, previous simulations have not been accurate."


In cooperation with colleagues from Germany and the United States, researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have managed to demonstrate diamond showers forming in the ice giants of our solar system. Using the ultra-strong X-ray laser and other facilities at the Stanford Linear Accelerator Center (SLAC) in California, they simulated the conditions inside the cosmic giants. For the first time ever, they were capable to notice the fission of hydrocarbon and the conversion of carbon into diamonds in real time. They published their results in the journal Mood Astronomy (DOI: 10.1038/s41550-017-0219).


The interior of planets like Neptune or Uranus consists of a solid core swathed in thick layers of "ice", which is mostly made up of hydrocarbons, water and ammonia. For a long time, astrophysicists have been speculating that the extreme pressure that reigns more than 10,000 kilometers beneath the surface of these planets splits the hydrocarbons causing diamonds to form, which then sink deeper into the planets interior.


 


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"So far, no one has been capable to directly notice these sparkling showers in an experimental setting," says Kraus. That was precisely the breakthrough Kraus and his international team have now achieved: "In our experiment, we exposed a special kind of plastic - polystyrene, which also consists of a blend of carbon and hydrogen - to conditions similar to those inside Neptune or Uranus."


They did this by driving two shock waves through the samples, triggered by an extremely powerful optical laser in combination with the X-ray source Linac Coherent Light Source (LCLS) at SLAC. At a pressure of about 150 gigapascal and temperatures of about 5,000 degrees Celsius, they compressed the plastic.


"The first smaller, slower wave is overtaken by another stronger second wave," Dominik Kraus explains. "Most diamonds form the moment both waves overlap." And since this process takes only a fraction of a second, the researchers used ultrafast X-ray diffraction to take snapshots of the diamonds creation and the chemical processes involved. "Our experiments show that nearly all the carbon atoms compact into nanometer-sized diamonds," the Dresden researcher summarizes.


Based on these results, the authors of the study assume that the diamonds on Neptune and Uranus are much larger structures and likely sink down to the planet core over a period of thousands of years.


The researchers from HZDR and SLAC were joined by scientists from the University of California in Berkeley, the Lawrence Livermore National Laboratory, the Lawrence Berkeley National Laboratory, the GSI Helmholtzzentrum fr Schwerionenforschung, the University of Osaka, TU Darmstadt, the European XFEL, the University of Michigan, and the University of Warwick.


The Daily Galaxy via The Helmholtz-Zentrum Dresden-Rossendorf (HZDR)


Image credit: Greg Stewart / SLAC National Accelerator Laboratory and pics-about-space.com




       





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