4419 - SOLAR ECLIPSE – 2024 , much more to learn?

 

-    4419  -  SOLAR  ECLIPSE – 2024 , much more to learn?       Although Earth-based telescopes can provide images of the sun in a higher resolution, these telescopes can't study the extreme ultraviolet part of the solar light spectrum. Because these frequencies are filtered out by Earth's atmosphere, ground-based telescopes therefore don't see many of the key phenomena driving the sun's behavior.

-------------------------  4419    -    SOLAR  ECLIPSE – 2024 , much more to learn?

-    There is a gap in our observations of the sun. Part of its atmosphere is effectively invisible to our telescopes. However, images taken from Earth during a solar eclipse are filling in that hole, providing an unprecedented look at our star's hidden layer.

-

-   On eclipse day, 66 cameras fitted with special filters and distributed across three observing locations in Mexico,  April 6, 2024, and the U.S. will capture tens of thousands of images during the roughly four-minute eclipse.

-

-   Made of extremely thin, charged gas called plasma, the solar corona is the upper part of the sun's atmosphere. It is a million times dimmer than the underlying photosphere that makes up the sun's visible surface, so it is completely outshined by the light of the star when viewed in visible light.

-

-   To observe the corona, astronomers need to obscure the visible solar disk to allow the faint coronal light to appear against the dark cosmos. To do this, they use an instrument called a coronagraph, which is equipped with an occulter that blocks the sun's light.

-

-   However, if the occulter were to cover only the visible sun, the diffraction, the bending of light around an obstacle, would let the bright light of the photosphere spill around the occulter's edges and ruin the photographs. Therefore, astronomers use bigger occulters that also cover the inner corona up to the distance of one solar radius from the sun's surface.

-

-    The moon, however, being far away, causes no diffraction while being just the right size to perfectly cover the solar disk during a total eclipse.   If you take images from space telescopes such as the Solar Dynamics Observatory, you can see the sun's surface in extreme ultraviolet light.

-

-    The corona is the source of the solar wind, the constant stream of charged particles that expands across the solar system. Occasionally, it erupts with massive outbursts known as “coronal mass ejections”, which can cause dramatic geomagnetic storms on Earth. Many of the processes that accelerate this solar wind into space happen in the coronagraph's blind spot: The sun itself.

-

-    The coronal gas, made mostly of ionized hydrogen and helium, with a smattering of heavier elements, such as iron, magnesium, silicon or calcium, loops around the sun's magnetic-field lines. Elsewhere, it streams into space from large sunspots or active regions and flows from coronal holes where the magnetic-field lines are broken.

-

-     In addition to capturing the white light of the corona, the researchers can now visualize spectral lines of various energetic ions present in the coronal gas. This opens the door for more exciting science.   Different types of ions emerge at different temperatures, so by imaging spectral lines of different types of ions, we can measure the temperature in different parts of the corona. 

-

-   Newly discovered fast magnetic waves might explain why the sun's corona is so hot. Scientists may have just found what makes the sun's outer atmosphere, the corona, so inexplicably hot.

-

-   For decades, scientists have been struggling to explain why temperatures in the sun's outer atmosphere, the corona, reach mind-boggling temperatures of over 1.8 million degrees Fahrenheit. The sun's surface has only about 10,000 degrees F, and with the corona farther away from the source of the heat inside the star, the outer atmosphere should, in fact, be cooler.

-

-    Using images taken by the “Extreme Ultraviolet Imager” (EUI), a camera that detects the high-energy extreme ultraviolet light emitted by the sun, scientists have discovered small-scale fast-moving magnetic waves that whirl on the sun's surface. These fast-oscillating waves produce so much energy, according to latest calculations, that they could explain the coronal heating.

-

-    Scientists have previously detected slower magnetic waves, but those didn't seem to produce enough energy to explain the enormous temperature difference between the sun's surface and the outer atmosphere.

-

-    Over the past 80 years, astrophysicists have tried to solve this problem and now more and more evidence is emerging that the corona can be heated by magnetic waves.   Solar Orbiter, launched in February 2020, takes the closest images of the star at the center of our solar system.

-

-   Solar Orbiter, which makes regular approaches to less than 48 million miles from the sun (closer than the orbit of the solar system's innermost planet Mercury), doesn't have those issues.  In its first images of the sun alone, released in June 2020, Solar Orbiter found other indications of processes that might play a role in the coronal heating mystery.

-

-

April 4, 2023        SOLAR  ECLIPSE – 2024 , much more to learn?          4419

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--------------------- ---  Friday, April 5, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4418 - EXOPLANET FOUND - will it host life

 

-    4418  -  EXOPLANET  FOUND  -  will it host life?      Hycean Planet Found? “TOI-270 d”.  It may be able to host life even though being outside what scientists consider the regular habitable zone. Exoplanet's thick atmospheres can trap enough heat to keep the oceans warm even though they’re not close to their stars.

------------------------- ? 4418    -   EXOPLANET  FOUND  -  will it host life

-    The word “hycean” is a portmanteau of ‘hydrogen’ and ‘ocean’ and it describes worlds with surface oceans and thick hydrogen-rich atmospheres. Scientists think that they may be common around red dwarfs and that they could be habitable, although any life that exists on a hycean world would be aquatic.

-

-    Because they contain so much water, scientists think they’re larger than comparable non-hycean planets. Their larger size makes them easier targets for atmospheric study by the JWST.

-

-    The telescope’s ability to characterize exoplanet atmospheres could be the key to confirming their existence. Using transmission spectroscopy, the space telescope can watch as starlight travels through their atmospheres, revealing the presence of certain important chemicals and even biosignatures.

-

-    The exoplanet “TOI-270 d" could be a hycean world.   The JWST has ushered in a new era in atmospheric characterizations of temperate low-mass exoplanets with recent detections of carbon-bearing molecules in the candidate Hycean world “K2-18 b,” .

-

-     TOI-270 is an M-dwarf (red dwarf) star about 73 light-years away. Red dwarfs are known to sometimes flare violently, ruling out habitability on nearby planets. However, TOI-270 is a quiet star. It hosts three sub-Neptune planets, and the pair of outermost planets, TOI-270 c and d, are both candidate hycean worlds. TOI-270 d is considered the strongest candidate.

-

-    TOI-270 d is about 4.2 Earth masses and measures about 2.1 Earth radii. It takes just over   11 Earth days to complete an orbit, a fact that aids atmospheric study. The Hubble Space Telescope looked at TOI-270 d recently, and its observations suggested a hydrogen-rich atmosphere with some evidence of H2O.

-

-    Though scientists still haven’t proven that hycean worlds exist, they know something about their atmospheric chemistry. On an ocean world with a thick, hydrogen-rich atmosphere, scientists expect to find strong signatures of CH4 (methane) and CO2 and no evidence of NH3 (ammonia.) This is what the JWST found at K2-18b, though there is still uncertainty if that exoplanet is a hycean world.

-

-     Every planet is different, but each type should have things in common. For Hycean worlds, the presence of an ocean below a thin H2-rich atmosphere may be inferred by an enhancement of CO2, H2O, and/or CH4, together with a depletion of NH3.  Since TOI-270 d is a candidate hycean world, its spectroscopy should be similar to other hycean candidates like K2-18b.

-

-   In October, 2023, the JWST observed TOI-270 b and d during two transits. The observations amounted to a total exposure time of 5.3 hours. This rare event allows for transmission spectroscopy of both planets.

-

-    The appearance of CS2 (carbon disulphide) in TOI-270 d’s atmosphere is intriguing. It’s considered a detectable biomarker in hycean world atmospheres, as well as in hydrogen-rich atmospheres of rocky worlds, although the direct sources could also be volcanic or photo-chemical.

-

-    The atmospheric spectrum also contains hints of C2H6 (ethane.) Ethane can be a byproduct of photo-chemical reactions involving methane and other gases, including biogenic ones. Its presence is another indication that methane is present.

-

-   The abundances of ethane and carbon disulphide are well above theoretical predictions.  All the researchers can conclude is that TOI-720 d is a candidate hycean world. But while the previous HST observations that hinted at its status showed the presence of H2O in an H2-rich atmosphere, the JWST observations provide more depth. The JWST’s more robust detections of CH4 and CO2, along with its non-detection of NH3, makes it an even stronger hycean world candidate.

-

-  

March 29, 2023              EXOPLANET  FOUND  -  will it host life?            4418

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---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Thursday, April 4, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4417 - EXOPLANET - search for life

 

-    4417    -   EXOPLANET  -   search for life.  -    With all the in-motion SETI research underway, just how prepared are we for a confirmed, door-ringing neighborhood watch revelation?  We should begin to think about how we convey this information, possible impacts to society, to religion, to politics, to technology, to governments.​

-

-------------------------  4417    -  EXOPLANET  -   search for life

-

-    To spot potential intelligent life out there in the great beyond, first you must cast a net wide by using an array of techniques and technologies.  

-

-    Any "fishing expedition" for E.T. includes close-in studies of life in extreme environments right here on Earth, to help us recognize any signatures we might find on Mars or deep diving through the icy shell of Jupiter's moon, Europa.

-

-    The search can also blend in the use of space-based telescopes to inspect Earth-like planets circling their home stars. Then there's cupping a proverbial ear to the cosmos using radio telescopes to pick up any bustling interstellar civilization or perhaps look for far-off laser-pulsed communiqués from extraterrestrial homebodies.

-

-    These and other efforts are actively pursued by the “SETI Institute” in Mountain View, California. More than a hundred institute scientists are busily carrying out research in astronomy and astrophysics, astrobiology, as well as exoplanets, climate and bio-geoscience and the Search for Extraterrestrial Intelligence (SETI).

-

-     All 27 antennas that constitute the Very Large Array (VLA) in New Mexico have been outfitted with new gear to perform 24/7 SETI observations under a collaboration between the SETI Institute and the National Radio Astronomy Observatory, the group that operates the VLA.

-

-    "COSMIC” is really the most comprehensive SETI search on a single instrument in history.    It will analyze data for the possible presence of "techno-signatures" - detectable signatures and signals that shout out the presence of distant advanced civilizations.

-

-   In scientific circles, techno-signatures are viewed as a subset of the far more established search for "biosignatures", evidence of microbial or other primitive life loitering on some of the billions of exoplanets we now know exist.

-

-   This includes the SETI Institute's newly augmented Allen Telescope Array situated northeast of San Francisco. The Allen Telescope Array (ATA) has undergone antenna redesign and now is outfitted with high-end computers, signal processors, and other electronics making it far faster than ever before.   The instrument is performing at a level that it has never performed at since it was built.

-

-   SETI Institute scientists are to delve into powerful Fast Radio Bursts (FRBs), a head-scratching phenomenon wanting of explanation.

-

-   During nine years of deep space scoping, it showed our galaxy contains billions of exoplanets.  It told us that planets are everywhere and a lot of them are potentially habitable.

-

-     Launched on March 6, 2009, the Kepler space telescope became NASA's first mission to detect Earth-size planets in the habitable zones of their stars.

-

-

March 29, 2023       EXOPLANET  -   search for life                      4417

------------------------------------------------------------------------------------------                                                                                                                       

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---   Some reviews are at:  --------------     http://jdetrick.blogspot.com ----- 

--  email feedback, corrections, request for copies or Index of all reviews

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Thursday, April 4, 2024  ---------------------------------

 

 

 

 

 

         

 

 

4414 - NUCLEAR ENERGY - solution waiting to happen?

 

-    4414  -   NUCLEAR  ENERGY  -  solution waiting to happen?  -    In December 2022, after more than a decade of effort and frustration, scientists at the US National Ignition Facility (NIF) announced that they had set a world record by producing a fusion reaction that released more energy than it consumed, a phenomenon known as “ignition”.

-

-------------------------  4414  -  NUCLEAR  ENERGY  -  solution waiting to happen?

-

-    They have now proved that the feat was no accident by replicating it again and again.  The stadium-sized laser facility, housed at the Lawrence Livermore National Laboratory (LLNL) in California, has unequivocally achieved its goal of ignition in four out of its last six attempts, creating a reaction that generates pressures and temperatures greater than those that occur inside the Sun.

-

-    The NIF was designed not as a power plant, but as a facility to recreate and study the reactions that occur during thermonuclear detonations after the United States halted underground weapons testing in 1992. The higher fusion yields are already being used to advance nuclear-weapons research, and have also fueled enthusiasm about fusion as a limitless source of clean energy.

-

-     The NIF works by firing 192 laser beams at a frozen pellet of the hydrogen isotopes deuterium and tritium that is housed in a diamond capsule suspended inside a gold cylinder. The resulting implosion causes the isotopes to fuse, creating helium and copious quantities of energy.  December, 2022, those fusion reactions for the first time generated more energy, roughly 54% more, than the laser beams delivered to the target.

-

-    The facility set a new record on 30 July when its beams delivered the same amount of energy to the target, 2.05 megajoules, but, this time, the implosion generated 3.88 megajoules of fusion energy, an 89% increase over the input energy. Scientists at the laboratory achieved ignition during two further attempts in October,2023. And the laboratory’s calculations suggest that two others in June and September generated slightly more energy than the lasers provided, but not enough to confirm ignition.

-

-    Researchers can repeatedly hit a goal they’ve been chasing for more than a decade. Tiny variations in the laser pulses or minor defects in the diamond capsule can still allow energy to escape, making for an imperfect implosion, but the scientists now better understand the main variables at play and how to manipulate them.

-

-    It’s a long way from there to providing fusion energy to the power grid, however, and the NIF, although currently home to the world’s largest laser, is not well-suited for that task. The facility’s laser system is enormously inefficient, and more than 99% of the energy that goes into a single ignition attempt is lost before it can reach the target.

-

-   Developing more efficient laser systems is one goal of the DOE’s new inertial-fusion-energy research program. The agency announced $42 million over four years to establish three new research centers, each involving a mix of national laboratories, university researchers and industry partners, that will work towards this and other advances.

-

-    Most government investments in fusion-energy research have gone towards devices known as tokamaks, which use magnetic fields inside a doughnut-shaped ‘torus’ to confine fusion reactions. This is the approach under development at ITER, an international partnership to build the world’s largest fusion facility near Saint-Paul-lez-Durance, France.

-

-    The NIF latest series of experiments features a 7% boost in laser energy, which should, in theory, lead to even larger yields. The first experiment in this series was one of the successful ignitions, on 30 October. Although it didn’t break the record, an input of 2.2 megajoules of laser energy yielded an output of 3.4 megajoules of fusion energy.

-

-     For more than 50 years, the Palisades nuclear fission power plant provided safe and clean electricity to southwest Michigan.   Located about 40 miles west of Kalamazoo, MI and on the shore of Lake Michigan, the Palisades was shut down permanently in May, 2022.

-

-   It was subsequently purchased by Holtec International, a firm that specializes in managing nuclear fue and decommissioning nuclear power plants.  The plan was for Holtec to decommission Palisades and then use the location to build and commission two small modular reactors, the next generation of even safer, clean nuclear fission power plant technology.

-

-   The costs associated with building and commissioning of two small modular reactors would not be sufficiently covered by any Department of Energy loan guarantees. And, it was announced that the Department of Energy would provide a $1.52 billion loan guarantee to re-start Palisades.  Palisades will become the first ever nuclear power plant to be restarted in U.S. history.

-

-   For decades, there has been so much irrational resistance to nuclear power, specifically nuclear fission, that it has held back the development of next generation nuclear power, which is far safer.

-

-   The U.S. continues to produce more than 60% of its electricity from fossil fuels.  The solution has always been there, but ignorance and politics have set many countries back by decades. This has only meant that countries continue to use coal, natural gas, and even old growth forests to fuel energy needs.

-

-   Perhaps more surprising than the $1.52 billion loan guarantee for the restarting of Palisades, was the messaging coming out of the government.  The governor of Michigan said of the plans to restart Palisades that it would drive $363 million of regional economic impact and helping Michigan lead the future of clean energy.

-

-    Nuclear power is our single largest source of carbon-free electricity, directly supporting 100,000 jobs across the country and hundreds of thousands of more indirectly.   Has the tide finally turned for nuclear power? Have the realities of clean energy finally sunk in on those who are misinformed or delusional?

-

-    The Watts Bar Nuclear Power Plant commissioned its new Unit 2 power plant just in 2016.

That was the very first new nuclear power plant to be commissioned this century.   The Vogtle Electric Generating Plant in Georgia began operations last year. It felt like a minor miracle after a decade of development and an unbelievable cost of $35 billion.

-

-   So, two new nuclear fission power plants commissioned in the last 8 years, and now the approval to restart the operations of a third.  The reality is that energy production and demand continue to rise to all-time highs.  And more than 60% of all electricity produced in the U.S. continues to be from coal and natural gas.

-

-   If the goal is to reduce or eliminate emissions, then nuclear power is the only choice for baseload 24/7/365 electricity production. It always has been… And yet,  nuclear power, as a percentage of energy source, has been flat for the last 20 years.

-

-    But one thing is certain, demand will continue to increase.   Within a few years, the increase in electricity required to power artificial intelligence software will be more than 100 terawatt hours year and growing.  And then there are electric cars to recharge.

-

-   Aside from the demand, there have always been some stark realities related to energy production by energy source.   Energy sources that require massive material (thus environmental damage due to extensive mining) and large areas are inefficient and have environmental and economic disadvantages.

-

-     Nuclear energy has the smallest overall footprint, by far, with natural gas a distant second, and solar after that.   Or, how about the striking images of what happens to a solar power plant when it meets a hailstorm.

-

-    Considering all of the mining that had to take place to manufacture these panels, which have now become useless and will almost certainly end up in a landfill somewhere.  That’s not the solution to clean energy.

-

-

March 29, 2023            NUCLEAR  ENERGY  -  solution waiting to happen?       4414

------------------------------------------------------------------------------------------                                                                                                                       

--------  Comments appreciated and Pass it on to whomever is interested. ---

---   Some reviews are at:  --------------     http://jdetrick.blogspot.com ----- 

--  email feedback, corrections, request for copies or Index of all reviews

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Tuesday, April 2, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4416 - SUPERNOVA EXPLOSION - we live on what's left behind?

 

-    4416  -    SUPERNOVA  EXPLOSION  -  we live on what's left behind?  -   The threat posed by stellar cataclysms such as supernovae and related phenomena such as gamma-ray bursts are cataclysms are remote, but when they occur closer to home they can pose a threat to life on Earth.

-----------  4416    -    SUPERNOVA  EXPLOSION  -  we live on what's left behind?

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-    Supernovae are exploding stars and they are rare.   They emit torrents of radiation.  One close enough to Earth could threaten life on the planet.

-

-    Stars like the sun are remarkably constant. They vary in brightness by only 0.1% over years and decades, thanks to the fusion of hydrogen into helium that powers them. This process will keep the sun shining steadily for about 5 billion more years, but when stars exhaust their nuclear fuel, their deaths can lead to pyrotechnics.

-

-    The sun will eventually die by growing large and then condensing into a type of star called a “white dwarf”. But stars more than eight times more massive than the sun die violently in an explosion called a “supernova”.

-

-    Supernovae happen across the Milky Way only a few times a century, and these violent explosions are usually remote enough that people here on Earth don't notice. For a dying star to have any effect on life on our planet, it would have to go supernova within 100 light years from Earth.

-

-    Very few stars are massive enough to die in a supernova. But when one does, it briefly rivals the brightness of billions of stars. At one supernova per 50 years, and with 100 billion galaxies in the universe, somewhere in the universe a supernova explodes every hundredth of a second.

-

-   The dying star emits high energy radiation as gamma rays. Gamma rays are a form of electromagnetic radiation with wavelengths much shorter than light waves. They're invisible to the human eye. The dying star also releases a torrent of high-energy particles in the form of cosmic rays which are subatomic particles moving at close to the speed of light.

-

-   Supernovae in the Milky Way Galaxy are rare, but a few have been close enough to Earth that historical records discuss them. In 185 A.D., a star appeared in a place where no star had previously been seen. It was probably a supernova.

-

-    Observers around the world saw a bright star suddenly appear in 1006 A.D. Astronomers later matched it to a supernova 7,200 light years away. Then, in 1054 A.D., Chinese astronomers recorded a star visible in the daytime sky that astronomers subsequently identified as a supernova 6,500 light years away.

-

-   Johannes Kepler observed the last supernova in the Milky Way in 1604, so in a statistical sense, the next one is overdue.

-

-    At 600 light years away, the red supergiant Betelgeuse in the constellation of Orion is the nearest massive star getting close to the end of its life. When it goes supernova, it will shine as bright as the full moon for those watching from Earth, without causing any damage to life on our planet.

-

-   If a star goes supernova close enough to Earth, the gamma-ray radiation could damage some of the planetary protection that allows life to thrive on Earth. There's a time delay due to the finite speed of light. If a supernova goes off 100 light years away, it takes 100 years for us to see it.

-

-   Astronomers have found evidence of a supernova 300 light years away that exploded 2.5 million years ago. Radioactive atoms trapped in seafloor sediments are the telltale signs of this event. Radiation from gamma rays eroded the ozone layer, which protects life on Earth from the sun's harmful radiation. This event would have cooled the climate, leading to the extinction of some ancient species.

-

-    Safety from a supernova comes with greater distance. Gamma rays and cosmic rays spread out in all directions once emitted from a supernova, so the fraction that reach the Earth decreases with greater distance. For example, imagine two identical supernovae, with one 10 times closer to Earth than the other. Earth would receive radiation that's about a hundred times stronger from the closer event.

-

-    A supernova within 30 light years would be catastrophic, severely depleting the ozone layer, disrupting the marine food chain and likely causing mass extinction. Some astronomers guess that nearby supernovae triggered a series of mass extinctions 360 to 375 million years ago. Luckily, these events happen within 30 light years only every few hundred million years.

-

-    Neutron stars merge when gravity pulls them together, which releases intense radiation when neutron stars collide.   So, supernovae aren't the only events that emit gamma rays. Neutron star collisions cause high-energy phenomena ranging from gamma rays to gravitational waves.

-

-   Left behind after a supernova explosion, neutron stars are city-size balls of matter with the density of an atomic nucleus, 300 trillion times denser than the sun. These collisions created many of the gold and precious metals on Earth. The intense pressure caused by two ultradense objects colliding forces neutrons into atomic nuclei creates heavier elements such as gold and platinum.

-

-   A neutron star collision generates an intense burst of gamma rays. These gamma rays are concentrated into a narrow jet of radiation that packs a big punch.  If the Earth were in the line of fire of a gamma-ray burst within 10,000 light years, or 10% of the diameter of the galaxy, the burst would severely damage the ozone layer. It would also damage the DNA inside organisms' cells, at a level that would kill many simple life forms like bacteria.

-

-   That sounds ominous, but neutron stars do not typically form in pairs, so there is only one collision in the Milky Way about every 10,000 years. They are 100 times rarer than supernova explosions.   But, across the entire universe, there is a neutron star collision every few minutes.

-

-   Gamma-ray bursts may not hold an imminent threat to life on Earth, but over very long time scales, bursts will inevitably hit the Earth. The odds of a gamma-ray burst triggering a mass extinction are 50% in the past 500 million years and 90% in the 4 billion years since there has been life on Earth.

-

-   By that math, it's quite likely that a gamma-ray burst caused one of the five mass extinctions in the past 500 million years. Astronomers have argued that a gamma-ray burst caused the first mass extinction 440 million years ago, when 60% of all marine creatures disappeared.

-

-    The most extreme astrophysical events have a long reach.   Astronomers were reminded of this in October 2022, when a pulse of radiation swept through the solar system and overloaded all of the gamma-ray telescopes in space.

-

-   It was the brightest gamma-ray burst to occur since human civilization began. The radiation caused a sudden disturbance to the Earth's ionosphere, even though the source was an explosion nearly 2 billion light years away. Life on Earth was unaffected, but the fact that it altered the ionosphere is sobering, a similar burst in the Milky Way would be a million times brighter.

-

-    Astronomers have found evidence that the bright gamma-ray burst “GRB 230307A” observed last year was caused by two neutron stars merging, not from a collapsing massive star. The study analyzed data from both the Hubble Space Telescope and the James Webb Space Telescope.

-

-   Prior research has shown that the strongest occasional flashes of light in the night sky are made by gamma-ray bursts. There are two basic kinds of GRBs: those that last longer than two seconds and those that are shorter. Study of these bursts has shown that the shorter bursts are typically the result of merging neutron stars. Longer bursts were believed to occur when a massive star collapses.

-

-   Neutron stars are created when massive supergiant stars collapse during a supernova. Once created, they can wander aimlessly alone through space. Sometimes, though, they travel close to another neutron star, forming a neutron binary system. As they orbit one another, they release gravitational waves, which can be measured here on Earth.

-

-    As they spiral, they are also pulled more tightly to one another until they eventually merge, emitting a massive burst of gamma rays, which on Earth looks like a bright burst of light,  called “kilonovae”. In studying GRB 230307A, researchers found that not only had it had been the source of the second-largest gamma-ray burst ever recorded, but it was also due to a kilonova, confounding theories regarding how GRBs are created.

-

-    The merger itself, and the material left after the collision was the first study of its kind. In focusing on the atomic nuclei left behind after the collision, the researchers found evidence of the creation of several heavy elements, including gold and silver. Further study of how such elements were formed, they suggest, could help to better understand how the universe as a whole was formed.

-

-

April 2, 2023      SUPERNOVA  EXPLOSION  -  we live on what's left behind?            4416

------------------------------------------------------------------------------------------                                                                                                                       

--------  Comments appreciated and Pass it on to whomever is interested. ---

---   Some reviews are at:  --------------     http://jdetrick.blogspot.com ----- 

--  email feedback, corrections, request for copies or Index of all reviews

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Tuesday, April 2, 2024  ---------------------------------

 

 

 

 

 

           

 

 

4415 - SOLAR ECLIPSE - in 2024, what we hope to learn?

 

-    4415  - SOLAR  ECLIPSE  -    in 2024, what we hope to learn? -  A total solar eclipse will be seen across the United States in April 2024.  When a rare total solar eclipse sweeps across North America on April 8, scientists will be able to gather invaluable data on everything from the sun's atmosphere to strange animal behaviors and even possible effects on humans.

-------------------------  4415    -   SOLAR  ECLIPSE  -    in 2024, what we hope to learn?

-   This solar eclipse comes with the sun near the peak of its 11-year solar cycle, setting the stage for a breathtaking display. The corona will glow spectacularly from the moon's silhouette along the path of totality, a corridor stretching from Mexico to Canada across the United States.

-

-  When the moon passes directly in front of the sun and blocks it, the elusive outermost edge of the sun's atmosphere, or corona, will be visible in a very special way.   Things are happening with the corona that we don't fully understand.

-

-   The heat within the corona intensifies with distance from the sun's surface.  This is a counter-intuitive phenomenon that scientists struggle to fully comprehend or explain.

-

-   Solar flares are a sudden explosion of energy that releases radiation into space.  They take place in the corona as do solar prominences, enormous plasma formations that loop out from the sun's surface.

-

-    During an eclipse, the bottom most part of the corona is more clearly visible than when using specialized instruments to block the central part of the sun.  This will afford scientists a chance to study changes in part of the Earth's upper atmosphere known as the ionosphere, important because it affects radio waves used for communication and navigation.

-

-    The ionosphere, which is where Earth's atmosphere meets space, is affected by the sun, which electrically charges the particles there during the day.  NASA's three sounding rockets will be launched before, during and just after the eclipse from Virginia to measure these changes.

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-    The major decrease in sunlight provoked by the eclipse should allow researchers to learn more about how light affects the ionosphere so they can better predict potential problematic disruptions.

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-    Beyond the drop in sunlight, temperatures and wind, conditions to which animals are sensitive can also decrease significantly during an eclipse.   Eclipses affect birds.   Weather surveillance radar are used to detect birds in flight to learn how migrations are affected.

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-   The 2017 eclipse disrupted the daily activities of insects and birds, but did not trigger usual animal nocturnal behaviors such as birds migrating or bats emerging.   This time around, birds might be more apt to migrate during the eclipse, given that it's in April.

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-   Eclipses have a special power. They move people to feel a kind of reverence for the beauty of our universe.  Scientists in the United States were excited to use the October "ring of fire" eclipse as valuable practice for a total eclipse in the Americas in 2024.

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-   An annular eclipse occurs when the moon is further away from Earth, causing it to be slightly smaller than the sun in the sky. The smaller moon is unable to block the entire disk of the sun, creating a "ring of fire" for a few minutes when the moon passes in front of the sun.

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-   The total solar eclipse that passes across the United States on April 8, 2024. You can get viewing details for totality at Space.com.

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-     “Inouye”, the world's largest solar telescope, will not be in the eclipse path during April 2024's events. But Inouye will provide a high-resolution "unobstructed view of the sun while the eclipse is happening. Inouye's results can then be compared with other telescopes to get a fuller picture of solar activity and its effects on Earth, particularly with the sun at a height of solar activity.

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-   Iinouye is like a microscope, essentially to zoom in and look at features we wouldn't be able to see otherwise without this type of high resolution, and then connecting it to other telescope observations.

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-   It will be able to view a very active corona, or upper atmosphere of the sun, during the precious minutes that the sun is nearly completely blocked by the moon. The sun is nearing its maximum of solar activity in its 11-year-cycle, unlike the last U.S. total solar eclipse of 2017, meaning that "the corona will be very active this time around.

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-    Solar activity has an immense impact on the ionosphere, which is a layer of Earth's atmosphere that interacts with electromagnetic radiation from above and below its extent. These interactions affect the propagation of radio signals.

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-    With the sun mostly blacked out temporarily by the eclipse, NSF will be carefully watching what happens when you suddenly turn off that X-ray and the ultraviolet rays from the sun that usually filter into the ionosphere and affect its extent.  The ionosphere actually expands and contracts depending on how much energy it is absorbing from the sun.

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-   The ham radio community will also help with ionospheric studies during the eclipse, using their GPS receivers to help professional scientists track changes in that layer of the Earth's atmosphere.

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-     Scientists will be watching local weather to see how it is affected by the lack of solar radiation. The moon's shadow traverses across the atmosphere at supersonic speeds, so things change fast and very quickly throughout the eclipse region.

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-    In April, 2024, scientists will chase the total eclipse in the Gulfstream-V aircraft to study the elusive "low corona," referring to the parts of the upper atmosphere of the sun that are not observable from space.

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-    Once this eclipse campaign is over, NSF says no other total solar eclipse will be visible in the United States until 2044.

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-   This total solar eclipse in North America could shed light on a persistent puzzle about the sun.   During the eclipse, the path of totality, where observers experience the darkest part of the moon's shadow (the umbra), crosses Mexico, arcing north-east through Texas, the Midwest and briefly entering Canada before ending in Maine.

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-   Total solar eclipses occur roughly every 18 months at some location on Earth. The last total solar eclipse that crossed the US took place on August 21, 2017.

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-   We can observe the sun's faint corona with incredible clarity, from distances very close to the sun, out to several solar radii. One radius is the distance equivalent to half the sun's diameter, about 696,000km (432,000 miles).

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-    Measuring the corona is extremely difficult without an eclipse. It requires a special telescope called a coronagraph that is designed to block out direct light from the sun. This allows fainter light from the corona to be resolved. The clarity of eclipse measurements surpasses even coronagraphs based in space.

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-   We can also observe the corona on a relatively small budget, compared to, for example, spacecraft missions. A persistent puzzle about the corona is the observation that it is much hotter than the photosphere (the visible surface of the sun). As we move away from a hot object, the surrounding temperature should decrease, not increase. How the corona is heated to such high temperatures is one question to be investigated.

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-    We have two main scientific instruments. The first of these is Cip (coronal imaging polarimeter). Cip is also the Welsh word for "glance," or "quick look." The instrument takes images of the sun's corona with a polariser.

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-   The light we want to measure from the corona is highly polarized, which means it is made up of waves that vibrate in a single geometric plane. A polarizer is a filter that lets light with a particular polarization pass through it, while blocking light with other polarizations.

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-    The Cip images will allow us to measure fundamental properties of the corona, such as its density. It will also shed light on phenomena such as the solar wind. This is a stream of sub-atomic particles in the form of plasma, superheated matter, flowing continuously outward from the sun. Cip could help us identify sources in the sun's atmosphere for certain solar wind streams.

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-    Direct measurements of the magnetic field in the sun's atmosphere are difficult. But the eclipse data should allow us to study its fine-scale structure and trace the field's direction. We'll be able to see how far magnetic structures called large "closed" magnetic loops extend from the sun. This in turn will give us information about large-scale magnetic conditions in the corona.

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-    The second instrument is “Chils” (coronal high-resolution line spectrometer). It collects high-resolution spectra, where light is separated into its component colors. Here, we are looking for a particular spectral signature of iron emitted from the corona.

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-    It comprises three spectral lines, where light is emitted or absorbed in a narrow frequency range. These are each generated at a different range of temperatures (in the millions of degrees), so their relative brightness tells us about the coronal temperature in different regions.

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-   Mapping the corona's temperature informs advanced, computer-based models of its behavior. These models must include mechanisms for how the coronal plasma is heated to such high temperatures. Such mechanisms might include the conversion of magnetic waves to thermal plasma energy. If we show that some regions are hotter than others, this can be replicated in the models.

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-   This year's eclipse also occurs during a time of heightened solar activity, so we could observe a coronal mass ejection (CME). These are huge clouds of magnetized plasma that are ejected from the sun's atmosphere into space. They can affect infrastructure near Earth, causing problems for vital satellites.

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-   Many aspects of CMEs are poorly understood, including their early evolution near the sun. Spectral information on CMEs will allow us to gain information on their thermodynamics, and their velocity and expansion near the sun.

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-    Our eclipse instruments have recently been proposed for a space mission called moon-enabled solar occultation mission (Mesom). The plan is to orbit the moon to gain more frequent and extended eclipse observations.

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-    We will also have an advanced commercial 360-degree camera to collect video of the April 8 eclipse and the observing site.

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March 29, 2023        SOLAR  ECLIPSE  -    in2024, what we hope to learn?           4412

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