Tagged: Astronomy Magazine Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 7:46 am on April 29, 2022 Permalink | Reply
    Tags: "How the James Webb Space Telescope will search for extraterrestrial life", Astronomy Magazine, , If Earth-sized planets were found to have an atmosphere similar to our home planet (that is containing mainly oxygen; nitrogen and carbon dioxide) that planet could likely support life forms., If the JWST detected CFCs in exoplanet atmospheres then that would be a tell-tale indication that a civilization is there., , Technological life could perhaps be identified by looking for the presence of chemicals that don’t occur naturally., The NASA Galileo spacecraft detected the vegetation red edge (VRE) biosignature-a mixture of red and infrared light that is reflected by plants.   

    From Astronomy Magazine: “How the James Webb Space Telescope will search for extraterrestrial life” 

    From Astronomy Magazine

    April 22, 2022
    Chris Holt

    The world’s most powerful telescope, now in space, will offer new tools to address the timeless question about life in the universe: Are we alone on Earth?


    Jurik Peter/Shutterstock.

    To date the only life we know about is here on Earth. Since the beginning of civilization, people have wondered whether there is life elsewhere in the universe. In 1984 American astronomer Jill Tarter and Thomas Pierson launched a project called Search for Extra-Terrestrial Intelligence (SETI), dedicated to that interstellar hunt.

    The nonprofit institute was designed to pick up radio signals from space. Radio signals can travel long distances because they are less scattered or absorbed compared to other sorts of radiation, making them more likely to be detected by the 42 radio telescopes that make up the one-of-a-kind Allen Telescope Array in the Cascade Mountains of California. But for 30 years, no verified alien signal has been received.

    Probing exoplanets

    Now, the James Webb Space Telescope (JWST) has been successfully deployed to aid the search. With its gigantic mirror and ultra-sensitive detectors, the world’s most powerful telescope (floating roughly 1 million miles away from Earth) will examine many distant unexplored planets orbiting distant stars. Twenty years ago, no other planets were known apart from those in our solar system. But since then, more than 4,000 other planets, called the exoplanets, have been discovered orbiting other stars. NASA estimates that the true number of exoplanets could be trillions.

    The first signs of life beyond our solar system might come from extraterrestrial plant life. The Galileo spacecraft, on its way to Jupiter, pointed its instruments back to Earth and picked up the distinct indication of the presence of plants.

    It detected the vegetation red edge (VRE) biosignature-a mixture of red and infrared light that is reflected by plants. The JWST will measure the VRE of distant Earth-like planets in the habitable zone around stars; and if there is a planet covered in jungle, for example, it should have a large VRE signal that should be easy to detect.

    There could be important signs of life in the composition of the atmospheres of the exoplanets. When an exoplanet passes across the face of its star, sunlight passes through its atmosphere and could be picked up by the JWST. Spectroscopy would then be used to discover which wavelengths are missing from the light. Atoms and molecules in the atmosphere absorb certain wavelengths and therefore leave a unique fingerprint for the JWST to detect. In that way, the composition of the atmosphere can be determined and the presence of life possibly inferred. If Earth-sized planets were found to have an atmosphere similar to our home planet (that is, containing mainly oxygen, nitrogen and carbon dioxide), that planet could likely support life forms.

    Technological life could perhaps be identified by looking for the presence of chemicals that don’t occur naturally. If aliens looked at the atmosphere of Earth from a distance, they would probably see chlorofluorocarbons (CFCs), which were manufactured for use in refrigeration and cleaning materials. Jacob Haqq-Misra at the Blue Marble Space Institute in Seattle has suggested that if the JWST detected CFCs in exoplanet atmospheres then that would be a tell-tale indication that a civilization is there.

    Recognizing life

    Of course living things on exoplanets might resemble nothing like life on Earth. Sometimes even life on Earth can seem alien, such as “extremophile” organisms. This is a class of organism, mostly microbes, that live in extremely harsh environments where life is impossible for other living creatures. Some live at very high temperatures, up to 250 Fahrenheit. Others survive extreme cold, as low as -4 Fahrenheit. Some live in strong acids with pH below 3, and there are other places on Earth where we would not expect to find life at all.

    However, it might be sensible initially to start looking at Earth-like planets where life is more likely — rather than those planets that have a temperature of 250 Fahrenheit, for instance, or are bathed in acid. Prime candidates might have a temperature where liquid water could form on the surface, and they’re orbiting around a stable star.

    Our Sun is classified as a G-type yellow star. But these stars tend to be short-lived and less common in space as we know it. More likely subject of study could be planets in orbit around the more numerous red dwarf stars, which are slightly cooler and less luminous than our Sun. These stars have much longer lifetimes, so there is more time for life to start up and evolution has more time to develop complicated life forms.

    First target

    The first project for JWST is to look at an exoplanet system called TRAPPIST-1, which is 40 light years away from us.

    This consists of seven rocky Earth-sized planets in orbit around a cool red dwarf star. Three of the rocky planets are in the so-called habitable zone, which means they could have liquid water on their surfaces. The TRAPPIST-1 star is only 1/10 the mass of our Sun and is much cooler, but the planets orbit close to the star so they receive light levels similar to here on Earth.

    Whether there is life anywhere else in the universe is one of the most important questions in science. The universe might be teeming with life, or maybe we are totally alone, marooned on a lonely world in the vastness of space. The definitive answer, either way, will likely require a profound psychological and philosophical adjustments for humankind.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 10:48 am on April 22, 2022 Permalink | Reply
    Tags: "Astronomers detect first potential 'rogue' black hole", , Astronomy Magazine,   

    From Astronomy Magazine: “Astronomers detect first potential ‘rogue’ black hole” 

    From Astronomy Magazine

    April 12, 2022
    Ashley Balzer

    We’ve seen plenty of black holes tearing material off a companion, but not sitting alone in space. Now, we might have spotted one.

    1
    A lone black hole gives off no light – but its gravity does distort the path of light traveling around it.
    Credit: Ute Kraus (background Milky Way panorama: Axel Mellinger), Institute of Physics, University of Hildesheim [[Universität Hildesheim](DE).

    Each second, a brand new baby black hole is born somewhere in the cosmos as a massive star collapses under its own weight.

    But black holes themselves are invisible. Historically, astronomers have only been able to detect these stellar-mass black holes when they are acting on a companion.

    Now, a team of scientists has made the first-ever confirmed detection of a stellar-mass black hole that’s completely alone. The discovery opens up the possibility of finding even more — an exciting prospect, considering there should be around 100 million such “rogue” black holes drifting through our galaxy unseen.

    Relying on the neighbors

    Black holes are difficult to find because they don’t shine like stars. Anything with mass warps the fabric of space-time, and the greater the mass, the more extreme the warp. Black holes pack so much mass into such a tiny area that space folds back in on itself. That means that if anything, even light, gets too close, its path will always bend back toward the center of the black hole.

    Astronomers have found a couple hundred of these ghostly goliaths indirectly, by seeing how they influence their surroundings. They’ve identified around 20 black holes of the small, stellar-mass variety in our galaxy by watching as stars are devoured by invisible companions. As the black hole pulls matter from its neighbor, the material forms a swirling, glowing accretion disk that signals the black hole’s presence.

    After decades of searching, astronomers have finally found an isolated stellar-mass black hole. Located about 5,200 light-years away toward the center of our galaxy, the yet-to-be-named rogue black hole weighs in at just over seven times the Sun’s mass. It’s moving faster than nearly all the visible stars in its area, which hints at how it formed.

    Scientists think that when a massive star runs out of fuel and collapses, the supernova explosion it experiences may be uneven. “This black hole seems to have gotten a natal kick at birth that sent it speeding away,” says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore, who led the study. The team’s results have been submitted to The Astrophysical Journal.

    2
    Gravitational lensing occurs when a massive foreground object bends and magnifies the light of a background object far behind it. When the lensing object is small (a star, planet, or black hole), this phenomenon is called gravitational microlensing.

    Seeing the Unseeable

    The team combined two cosmic techniques to spot the black hole: gravitational lensing and astrometry. The first works because when gravity warps space-time, it changes the path light takes when it passes close by. When a celestial object passes very close to a more distant star in the sky from our line of sight, the starlight bends as it travels past the closer object. If the foreground object doing the bending is relatively small — say, a planet, star, or black hole, rather than an entire galaxy or galaxy cluster — the process is called, specifically, microlensing.

    Microlensing makes the nearer object act as a natural magnifying glass, temporarily brightening the distant star’s light — an effect telescopes can pick up. Astronomers can roughly estimate how massive the nearer object is by how long the spike in starlight lasts; more massive objects create longer microlensing events. So, a long microlensing event caused by something we can’t see could signal a rogue black hole.

    But black holes can’t be confirmed by microlensing alone. A small, faint star moving slowly could masquerade as a black hole. It too would produce a long signal, due to its slow speed, and if the star is dim enough, astronomers might not see it, only able to detect light from the background star.

    That’s where astrometry comes in. This technique involves making precise measurements of an object’s position. By seeing how much the background star’s position appears to shift during a microlensing event, astronomers can very accurately find out how massive the nearer object is.

    “That’s how we knew we found a black hole,” Sahu says. “The object we detected is so massive that if it were a star, it would be shining brightly; yet we detected no light from it.”

    This discovery is the culmination of seven years of observations. The microlensing signals that can reveal small, solo black holes last almost a year. Two ground-based telescopes, the Optical Gravitational Lensing Experiment (OGLE) and Microlensing Observations in Astrophysics (MOA) telescope, picked up on the event. It lasted long enough that astronomers suspected the lensing object could be a black hole.


    That’s when they began making astrometric measurements. The deflection the intervening object caused in the background star’s light was so small that only the Hubble Space Telescope could detect it. The team spent several more years analyzing the astrometric signal, which in general can last five to 10 times longer than its microlensing counterpart.

    “It’s extremely gratifying to be part of such a monumental discovery,” Sahu says. “I’ve been searching for rogue black holes for more than a decade, and it’s exciting to finally find one! I hope it will be the first of many.”

    Establishing the cosmic norm

    It’s still possible the object may not be a black hole after all. A separate team’s analysis of the same event puts the object somewhere between about 1.5 and 4 solar masses — lightweight enough that it could be either a black hole or a neutron star (the crushed core of a dead star that wasn’t quite massive enough to become a black hole). Considering that astronomers have never detected an isolated neutron star before either, this would still be a remarkable discovery. Both teams’ results are still being peer-reviewed.

    Regardless of this result, some astronomers think the stellar-mass black holes found in binary systems may represent a biased sample. Their masses only range from about 5 to 20 times the Sun’s mass, with most weighing in at around 7 solar masses. But the true range may be much broader.

    “Stellar-mass black holes that have been detected in other galaxies via gravitational waves are often far larger than those we’ve found in our galaxy — up to nearly 100 solar masses,” Sahu says. “By finding more that are isolated, we’ll be better able to understand what the true black hole population is like and learn even more about the ghosts that haunt our galaxy.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 9:22 am on April 8, 2022 Permalink | Reply
    Tags: "The Sun’s coronal loops may be an optical illusion", Astronomy Magazine,   

    From Astronomy Magazine : “The Sun’s coronal loops may be an optical illusion” 

    From Astronomy Magazine

    April 1, 2022
    Mark Zastrow

    The arcs of plasma that dance above the Sun may actually be wrinkles in a vast veil of plasma.

    1
    Coronal loops appear on the limb of the Sun in this image captured by the Solar Dynamics Observatory July 12, 2012. Credit: NASA/Goddard Space Flight Center.

    Some of the most spectacular features on the Sun are its coronal loops — incandescent structures of hot plasma that arc for thousands of miles above magnetically active regions of the Sun, forming what appear to be curving strands.

    But appearances can be deceiving. Now, a team of solar physicists say these iconic structures may not actually be loops at all. Instead, the loops may be an illusion rooted in a more complex structure — a magnetic sheet or curtain that is being pulled and wrinkled. The team call this the coronal veil, and they think that bright coronal loops appear where the veil is wrinkled and our line of sight runs through more of it.

    The insight came from exploring simulations of the Sun’s magnetic field published March 2 in The Astrophysical Journal.

    “I have spent my entire career studying coronal loops,” said Malanushenko, a researcher at the National Center for Atmospheric Research in Boulder, Colorado, and the study’s lead author, in a statement. “I never expected this. When I saw the results, my mind exploded. This is an entirely new paradigm of understanding the Sun’s atmosphere.”

    Lifting the veil

    For decades, scientists have generally assumed that coronal loops are what they look like — strands of hot glowing plasma. Because plasma consists of particles with an electric charge, their movements are influenced by the Sun’s magnetic field. Physicists say that plasma is “frozen in” to a magnetic field: The magnetic force guides plasma along magnetic field lines, the same lines that iron filings trace out around a bar magnet. Therefore, it’s not much of a stretch to think that these bright loops are thin strands of frozen-in plasma, following the curvature of the magnetic field.

    However, there are a couple issues with the strands hypothesis that call it into question. One is that magnetic field lines tend to fan out further from their source — whether that source is a bar magnet or a group of sunspots. That means if coronal loops are strands that trace magnetic field lines, they should also fan out and get wider high above the Sun’s surface. But that’s not what observations show. “The consensus is that they do expand with height but not nearly as much as we think they should,” Malanushenko told Astronomy.

    The other issue with the strands hypothesis is related to how the Sun’s atmosphere becomes less dense further away from its visible surface. This means that the tops of coronal loops should also be thinner and therefore not as bright as at their bases. Instead, they maintain a relatively even brightness from top to bottom.

    3
    These physical models demonstrate the difference between the traditional description of coronal loops as strands of plasma (left) and the new, proposed explanation that they are wrinkles in a plasma veil (right).
    Credit: Anna Malanushenko.

    But these inconsistencies go away under the veil hypothesis, where the loops don’t correspond to compact plasma strands, but are instead a perspective effect caused by wrinkles in a sheet of plasma. The effect is analogous to a thin veil: When the material bunches up so that we see it edge-on or is folded so that we are looking through multiple layers, it absorbs more light and blocks our view of what is behind it. Of course, because plasma in the solar corona is emitting light — not absorbing it — such wrinkles appear brighter to us, not darker.

    Hard to test

    The fact that we don’t have much experience with thin sheets of glowing gases in everyday life is likely part of the reason the wrinkled veil hypothesis hasn’t been seriously considered before, says Malanushenko.

    But there are some astrophysical precedents in the night sky — most famously, the Veil Nebula, which consists of the remnants of an expanding cloud of debris from a supernova in the constellation Cygnus 10,000 to 20,000 years ago.

    The object consists of what appear to be ropelike filaments, but the common explanation is that the expanding shock wave of heated gas forms a thin layer that is visible to us only when it is wrinkled and bunched up along our line of sight.

    For the Sun, the team backs up the veil hypothesis qualitatively with examples from a widely used model of the solar magnetic field called MURaM, developed by researchers at The MPG Institute for Solar System Research [Max-Planck-Institut für Sonnensystemforschung](DE), and The University of Chicago.

    “I was very excited that in a simulation, I could take a scalpel and slice the model in different sections, isolate individual loops, and study them,” says Malanushenko. “And what I saw was nothing like what I expected.”

    Features that appeared like coronal loops from one angle, when viewed in cross section, were not bundles of strands but swirling sheet-like features.

    4
    In this MURaM simulation of the Sun’s magnetic field, features that look like coronal loops (left) are formed from swirling sheets of plasma (right). Credit: Anna Malanushenko.

    The team readily acknowledges that much more work must be done to verify their hypothesis — and there are plenty of challenges in doing so observationally, says Malanushenko. The team thinks the structures are so complex that even with multiple viewpoints, it would be very hard, if not impossible, to tell which loop is which and determine the geometry of the veil, if it exists.

    Making direct measurements of the coronal veil with spacecraft is also beyond our capabilities at the moment. NASA’s Parker Solar Probe, launched in 2018, will make the closest ever approach by a spacecraft to the Sun, coming within 4 million miles (6.4 million kilometers) of its visible surface. But to directly sample coronal loops or make in situ measurements, a craft would have to get about 1,000 times closer.

    For now, the team plans to follow up by performing more modeling and comparing the results to observations. One strategy to distinguish between the loop and veil theories is to look at the contrast in brightness of apparent loops, as well as the space between them. Strands should stand out starkly against their background, while a veil would result in more diffuse emission between the bright wrinkles.

    It’s possible that improvements in modeling will enable a stronger observational strategy, says Malanushenko. “Given the strength of this impact, yes, we should be careful. We should look for observational confirmation.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 10:02 am on March 11, 2022 Permalink | Reply
    Tags: "Do supermassive black holes stifle star formation within galaxies?", Astronomy Magazine, , ,   

    From Astronomy Magazine : “Do supermassive black holes stifle star formation within galaxies?” 

    From Astronomy Magazine

    March 3, 2022
    Connor Lynch

    Not all galactic neighborhoods are under construction; some have gone quiet. A new paper sheds new light on the ongoing debate about the reasons why.

    1
    Yoshihiro Miyagi/Shutterstock

    Black holes are the closest things we have left to mythological monsters — the “Here be dragons” warning of our cosmological maps. The supermassive black holes at the center of galaxies deserve particular notice. They are the unbelievably massive anchors of the hundreds of billions of solar systems in our galaxy, as well as others.

    But not all interstellar communities are growing. Some are “quenched” galaxies, where new star formation appears to have ground to a halt. Why and how this happens has been frustrating astronomers and astrophysicists for 20 years. A recently published study [MNRAS] makes a strong case that the most important factor is at the very core of those galaxies, and the supernatural strength of black holes: their mass.

    Breaking up the chunks in interstellar soup

    University of Cambridge astronomer Joanna Piotrowska, the study’s lead author, explains that despite the complexity of black holes, galaxies and astrophysics in general, there are only two basic ways a galaxy can be star-quenching: either something is cutting off its supply of gas, or something is preventing that gas from accumulating.

    There have been three prevailing theories as to how this happens. All have to do with mass. The first — supernovae explosions — relies on the mass of the stars in the galaxy: supernovae explosions. Essentially, the theory says, exploding stars expel dust out of the galaxy and make it unavailable for star formation. Still, it supernovae are the weakest of the three options, and they don’t have the strength to throw cosmic dust completely out of reach.

    The next is halo shock-heating. Essentially, as a black hole draws material towards itself, that material is being forced through the halo of material already around it. This friction generates enormous amounts of energy, heating up the halo and letting it stay buoyant. As the theory goes, the more material being pulled in — or the more accretion happening, in technical terms — the more quenched a galaxy should be, which should increase the mass of the halo around the black hole.

    The final theory is very simple. Once black holes are massive enough, they become what are called active galactic nuclei, small regions at the center that emits massive amounts of energy, powerful enough to hurl jets of wind and dust around themselves.

    Their gravity injects massive amounts of turbulence and heat into the surrounding gas, preventing the gas from condensing and collapsing into stars. Just like a tetherball, hit with enough force, it will stay in the air, rather than falling back down against the pole. It’s this theory that Piotrowska and co-author Asa Bluck ascribe to in their research.

    A walk through a random forest

    To test that theory, the researchers combined cosmological observations from the Sloan Digital Sky Survey with three cosmological simulations — EAGLE, Illustris and IllustrisTNG — that allowed them them to analyze a whopping 200,000 galaxies. Looking at central galaxies (the ones at the heart of galactic superclusters), they employed a method of machine learning called a “random forest” to analyze them.

    In their analysis, the scientists fed the parameters of each of these three theories into an algorithm, then asked the machine learning program to make use of those parameters and try to replicate their observed results. Because the program is more simple, they were able to “figure out exactly what it’s doing, and why,” says Bluck. The problem with more complex machine learning methods is that understanding how they find answers is very difficult. “In terms of simplicity, you always want the simplest thing that solves the problem,” he says. “We didn’t want to hit a nail with a nuclear bomb; we used a hammer.” The results were pleasantly clear, Piotroska says. “The end result is [the theory of] black hole mass beats the other parameters by a long stretch.”

    “According to my honest knowledge,” she adds, “this is the most obvious and methodologically strong demonstration that supermassive black holes kill star formation in massive galaxies.”

    Graduate student Alex Gurvich of Northwestern University, who specializes in using simulations to study the interactions between stellar feedback and star formation and was not involved in this study, agrees. He says the research helps answer a longstanding mystery in astronomy, where one of the leading theories has been that accretion by the black hole should be the cause of quenching, and so the faster a black hole is accreting, the faster it should quench. But there are “confusing observational results,” he says, “where star formation is off, but there’s no accretion. And vice versa: star formation is happening, but so is accretion. Why isn’t it turned off yet?” The question hints at the idea that total black hole mass, not accretion at any given moment in time, is more important in quenching star formation. And this paper, he says, nailed that down, calling it “a step forward not just for the field but its methodology.”

    For Bluck, the machine learning approach developed by Piotrowski helped the scientists avoid the trap of mistaking correlation for causation. (In other words, they were able to definitively show a galaxy’s massive size can cause it to halt star formation.) “By combining these two things, we go beyond correlation [between supermassive galaxies and star-quenching] and approach causation,” Bluck says. “And when you consider these are things sometimes billions of light years away, feeling we can say something definitive about causation is awesome.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 6:14 pm on February 18, 2022 Permalink | Reply
    Tags: "Finding Neptune-How we discovered the eighth planet", , Astronomy Magazine, , , ,   

    From Astronomy Magazine : “Finding Neptune-How we discovered the eighth planet” 

    From Astronomy Magazine

    February 10, 2022
    William Sheehan

    1
    Voyager 2 captured this stunning shot of Neptune with its narrow angle camera on Aug. 31, 1989.
    Credit: Kevin M. Gill- JPL/Caltech-NASA(US). Illustration: Tatyana Antusenok/Dreamstime.

    The story of how observers discovered Uranus and Neptune is among the most celebrated in the annals of astronomy. As the first modern additions to the solar system, joining the classical planets known to the ancients, the ice giants forever changed our conception of the universe. And the discovery of Neptune was an inspiring testament to the scientific method: A mysterious discrepancy between observation and theory led to a prediction that was validated in dramatic, cosmos-shattering fashion.

    At least, that’s how the story usually goes. But finding Neptune was less straightforward than the story suggests. It’s a tale filled with fascinating characters, missed opportunities, and even international intrigue. And in the end, the entire discovery hinged on a crucial bit of luck that went unnoticed for nearly 150 years.

    A discovery re-discovered

    It’s easy to forget that for most of the 18th century, the solar system was a remarkably simple and straightforward place (which certainly made orrery-makers’ jobs easier). There was the Sun, the seven planets including Earth, our Moon, the four moons of Jupiter, the five moons of Saturn, and a few periodic comets. The zone between Mars and Jupiter, soon to fill in with asteroids, was still empty. The entire outer solar system beyond Saturn and below the sphere of the fixed stars was devoid of features, as it had been since Aristotle’s time. And all the solar system’s bodies moved tidily and predictably according to Newton’s law of gravity.

    But this ancient, elegant picture was shattered by William Herschel’s serendipitous discovery of Uranus in March 1781. And that was just the beginning when it came to shaking up the solar system: The new planet’s orbit obstinately refused to follow the path mathematicians insisted it should, pointing to another hidden planet lurking beyond.

    In 1821, a now largely forgotten French astronomer named Alexis Bouvard published tables of Uranus’ motion, over which he had toiled for many years. Bouvard was a shepherd boy who rose, improbably, to become director of The Paris Observatory [Observatoire de Paris – PSL Centre de recherche en astronomie et astrophysique](FR). He was attempting to combine pre-discovery observations of Uranus from star catalogs (the earliest was from 1690) with the presumably far more accurate observations made since Herschel uncovered the world.

    But he couldn’t do it. He discarded the older observations, and for a moment, Uranus’ observed motion seemed to be reconciled with theory. However, soon it was off course again. Before 1821, Uranus appeared to be moving faster than it should have been, based on the known bodies near it. But within a few years, it appeared to be moving too slowly. Bouvard himself suspected an unknown planet might be the cause, yet he did nothing to follow up.

    Seeking the answer

    Over the years, the nagging difficulty of explaining the future path of Uranus only got worse. Eventually, two mathematical astronomers began to investigate.

    One was John Couch Adams, a native of Cornwall. Adams took nearly all the prizes in mathematics as an undergraduate at St. John’s College, Cambridge, and was awarded a fellowship. The other was Urbain Jean Joseph Le Verrier of France, a répétiteur (private tutor or assistant teacher) at the École Polytechnique (FR) who devoted most of his time to researching celestial mechanics.

    Adams got interested in the Uranus problem on his own, sketching his first plan to investigate as an undergraduate in 1841. Le Verrier, having already published important work on the stability of the solar system, was instead drafted onto the job during the summer of 1845 by the then-director of the Paris Observatory, François Arago. Arago had become frustrated by the lack of progress being made on the theory of Uranus by Eugène Bouvard, Alexis’ nephew, who had been assigned the investigation after Alexis retired.

    Few people are familiar with the intricacies of classical celestial mechanics anymore. And hardly anyone undertakes the incredibly long calculations with pencil and paper that were once required. Moreover, the prolonged concentration needed for such calculations feels quaint in an age of constant internet and media buzz. As a result, it is a bit difficult today to imagine just how challenging was the problem Adams and Le Verrier set for themselves.

    It had, of course, always been mathematical astronomers’ jobs to make predictions. They used Kepler’s laws to predict planets’ future positions given elements of their elliptical orbits, and applied Newton’s theory of gravitation to Keplerian elliptical motion to account for perturbations due to other planets. All of this was very complicated and tedious, but fairly straightforward, provided that one had accurate orbital elements and that the desired prediction wasn’t too far into the future. (Even with a supercomputer, the long-term effects of three-body interactions soon get very ugly.)

    In searching for the distant planet, however, Adams and Le Verrier had to reverse-engineer the operations. Instead of starting with Uranus’ orbital elements and computing the motions of the unknown perturber, they had to start with Uranus’ motions and try to firmly pin down the orbital elements that explained them. “Doing multi-parameter minimization, which is what they were trying to do, is no easy task, especially if you don’t have a computer,” says Greg Laughlin, an astronomer at Yale University and an expert in numerical simulations.

    Luckily, Adams and Le Verrier were up to the task, albeit in their own eccentric ways. Adams was extraordinarily conscientious in both his studies and tutorial responsibilities, permitting himself to indulge his Uranus hobby only during vacations. He was also capable of carrying out long and tedious calculations in his head without missing a beat, as was Le Verrier.

    Using data on the observed motion of Uranus obtained from the Royal Observatory in Greenwich, Adams attempted to use the unknown planet hypothesis to reconcile observation with theory. In the end, Adams carried out six calculations using different hypotheses. His first two calculations used the simplifying assumption of a circular orbit. And all but the last relied on the semi-empirical Bode’s law — which predicted that each planet (moving outward) should be about twice as far from the Sun as the last ­— to determine the supposed world’s mean distance.

    He finished his most accurate calculations in September 1845 and made slight corrections the following month. These gave theoretical positions for the presumed planet. As it would turn out, they were only off by a quite searchable 2° on either side of where Neptune really was at the time. Still, no one searched for the new world.

    Adams communicated his first result to his overworked teacher and director of the Cambridge Observatory, James Challis. Having mountains of other work piled on his desk, Challis did what any overextended person would do: He suggested Adams take his ideas up the ladder to a higher authority.

    That authority was the Astronomer Royal, George Biddell Airy. With a letter of introduction to Airy but no formal appointment, Adams attempted to pay Airy an unannounced visit. Adams attempted three total visits, once on the way to, and twice returning from, a vacation in Cornwall. Airy was home, but did not receive Adams, so Adams left a note. To the Astronomer Royal’s credit, Airy did follow up with a response letter, in which he posed to Adams a rather technical question.

    Adams never replied. The late astronomy historian Craig Waff did discover during a visit to the Truro Records office in 2004 that Adams had begun to draft a letter back to Airy. The reason it wasn’t sent will likely never be known; perhaps it was merely a matter of becoming absorbed with other duties, with a chaser dose of procrastination. As always in the course of history, the discovery story of Neptune includes a trail of wistful what-might-have-beens.

    The discovery in Berlin

    Except for a few further computations made at the end of 1845, Adams laid the Uranus problem aside for a time. In early 1846, he started helping Challis compute comet orbits from Challis’ backlog of observations. The initiative to explain the orbit of Uranus fell on Le Verrier and the French.

    Le Verrier attacked the problem with his considerable computational abilities. He was “a calculating machine,” says Guy Bertrand, a graduate student at Paris Observatory. “He double-checked every calculation and did a lot of them mentally.” For his Ph.D. dissertation, Bertrand is reconstructing all of Le Verrier’s calculations — no small feat, considering he published only brief summaries of them. “There are thousands of these scraps of paper,” says Bertrand. “In all these pages, I found hardly any errors.”

    On June 1, 1846, Le Verrier announced his results so far, and included a position for the planet that, as Airy recognized immediately, was close to the location that Adams had proposed the previous autumn. Airy saw an opportunity and used his influence to get Challis to search that region of the sky at Cambridge University Observatory using the 11.6-inch Northumberland refractor.

    3
    The telescope used by Galle and d’Arrest to discover Neptune, originally at Berlin Observatory, is now on display in the German Museum of Masterpieces of Science and Technology [Deutsches Museum von Meisterwerken der Naturwissenschaft und Technik](DE). Credit: William Sheehan.

    Challis obliged, and started a thorough if rather plodding hunt, which would have led to the discovery of the planet eventually. Indeed, he even recorded Neptune twice in early August, but did not get around to comparing its changing position between observations. Science historians have often criticized Challis as a bumbler, but he was at least looking.

    In France, meanwhile, Le Verrier encountered nothing but apathy. Finally, after he published a new calculation that put the planet just over a degree from where it actually was, and made a new pitch for astronomers to seek it out, Le Verrier found his man. Or rather men. They were Johann Galle, an astronomer at The Berlin Observatory (Berliner Sternwarte](DE), and a student named Heinrich Louis d’Arrest, who suggested using a star map just published in Berlin that was not yet distributed to astronomers elsewhere to aid in their search.

    4
    The heavily populated outer solar system is shown here as it appeared in April 2019. Unknown to even late-19th-century astronomers was the fact that beyond Neptune exists a vast ring of icy bodies called Kuiper belt objects (KBOs). A subset of these KBOs orbit the Sun in a 2:3 resonance with Neptune. Credit: Roen Kelly/
    Astronomy, after Minor Planet Center.

    After an hour’s work at the telescope on Sept. 23, 1846, with Galle calling out the positions of stars in the field and d’Arrest checking them on the map, one finally elicited the exclamation: “That star is not on the map!” Close scrutiny revealed the aquamarine world’s disc, of which Galle said, “My God in heaven, that’s a big fellow!” And so it was — a planet nearly the same size as Uranus and the last giant to be added to our solar system.

    An international furor

    The post-discovery history of Neptune is nearly as interesting as the find itself. The early efforts of Adams and Challis’ unavailing search came to light and provoked what threatened to be an international incident during a time of strained British-French relations. This was resolved with Le Verrier and Adams both receiving shares of the credit. A few historians have claimed there was a British conspiracy to doctor the documents in order to steal credit from the French. But there is no evidence of this at all.

    4
    Five days before zipping by the solar system’s eighth planet in 1989, Voyager 2 captured this view of the ice giant’s surprisingly complicated clouds. At center is a so-called great dark spot, a type of temporary neptunian storm. A patch of elongated cirrus clouds, called a scooter, is also visible to the north.
    NASA/JPL-caltech/Voyager-ISS/Justin Cowart.

    On the other hand, recent research has added new perspectives on some important issues about the calculations leading to the triumphant discovery. Soon after the discovery of Neptune, the American mathematician Benjamin Peirce suggested that Adams and Le Verrier had been lucky rather than good in some of their assumptions. In particular, those relating to the 2:1 orbital resonance between Uranus and Neptune. (For every orbit Neptune completes, Uranus completes roughly two.) Such resonances can wreak gravitational havoc: At the resonance itself, the planets’ orbits become unstable.

    Adams and Le Verrier assumed Neptune was just outside the resonance, allowing its orbit to remain stable. But there were early hints that this was an incorrect assumption. As Adams refined his sixth and final set of calculations, he grew nervous: The planet’s predicted orbit was getting uncomfortably close to the 2:1 resonance, which would make it unlikely to exist at all. But his worries had been misplaced. In fact, it was quickly determined after its discovery that Neptune lies just inside the 2:1 resonance. As a result, Peirce argued that the apparent accuracy of Le Verrier and Adams’ calculations was a “happy accident.”

    Most astronomers at the time, including Adams and Le Verrier, dismissed Peirce’s criticism — after all, the predictions had been accurate enough to successfully find Neptune. But Peirce had a valid point. The 2:1 resonance between the ice giants turns out to be extremely important in understanding how the planets’ gravitational pulls affect each other’s orbits.

    This was clearly shown in 1990, when a team of researchers at The Chinese University of Hong Kong [香港中文大学] (HK) published a paradigm-shifting paper that cleverly simplified the main features of the perturbation problem, eliminating the need to grasp the intricate arcana of classical celestial mechanics. With their model, they showed that the 2:1 resonance of Neptune perturbs Uranus’ orbital motion by an order of magnitude more than what Le Verrier and Adams had assumed. Le Verrier and Adams never uncovered these effects because they used incorrect values for Uranus’ orbit, including its eccentricity and average distance from the Sun.

    The reason the orbital perturbations were much stronger than Le Verrier and Adams thought is related to the fact that the 2:1 resonance is not exact. (The period of Neptune differs from twice that of Uranus by 2 percent.) Though Le Verrier and Adams worried about the 2:1 resonance destabilizing their calculations, they couldn’t anticipate a side-effect of the actual near-resonance. Namely, the orbital perturbation Uranus experiences undergoes “beats,” slow variations in amplitude that occur when two objects are very nearly, but not quite, in resonance, like strings of a musical instrument slightly out of tune.

    In light of this analysis, it turns out Le Verrier and Adams’ incomplete understanding of perturbation theory led them to make two mistakes. First, they made the deviations symmetric around the 1822 Uranus-Neptune conjunction, which was incorrect. The deviation from the mean motion that they thought was a maximum during this period was actually a minimum. Second, they entirely missed another possible location for Neptune, 180 degrees out of phase from the first, on the opposite side of the Sun! That they chose the position they did, which happened to be near the planet at the time, was indeed a happy accident.

    Nevertheless, their efforts represented a significant accomplishment. According to CUHK physicist Kenneth Young, who co-authored the 1990 paper, “Le Verrier’s and Adams’ calculations were valid within the limitations of the theory they used.” In fact, Young adds, “even a search with many fewer parameters than those actually involved would have been a major computational endeavor in the days before electronic computers.”

    So, the fulfillment of their prediction in d’Arrest’s exclamation, “That star is not on the map!” proves not to have been, as expected by later investigators, a model for future planetary discovery. Instead, it was a freak event, not likely to be repeated again in the history of astronomy.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 10:18 am on January 21, 2022 Permalink | Reply
    Tags: "Snapshot-Sagittarius A* gives its compliments to the chef", , Astronomy Magazine, , , , ,   

    From Astronomy Magazine : “Snapshot-Sagittarius A* gives its compliments to the chef” 

    From Astronomy Magazine

    January 7, 2022
    Caitlyn Buongiorno

    1
    Credit: Gerald Cecil/The University of North Carolina-Chapel Hill (US)/The National Aeronautics and Space Agency(US)/The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganisation](EU); Image Processing: Joseph DePasquale (The Space Telescope Science Institute (US)).

    Like any happy eater, our Milky Way’s supermassive black hole, Sagittarius A* (Sgr A*), belches every time it consumes a particularly hefty meal. The resulting small outbursts, or mini-jets, can be difficult to spot outright, but may leave traces in the surrounding gas.

    2
    SCIENCE: Gerald Cecil (UNC-Chapel Hill)/NASA, ESA; IMAGE PROCESSING: Joseph DePasquale (STScI).

    Such evidence of a blowtorchlike jet released just a few thousand years ago was outlined in a paper published Dec. 6 in The Astrophysical Journal. Though the jet wasn’t spotted directly, the Hubble Space Telescope instead saw indirect evidence of the jet’s material pushing on a nearby hydrogen cloud.

    National Aeronautics and Space Administration(US)/European Space Agency [Agence spatiale européenne] [Europäische Weltraumorganisation](EU) Hubble Space Telescope.

    Another lingering jet was previously spotted in 2013 by NASA’s Chandra X-ray Observatory and the Karl G. Jansky Very Large Array.

    The National Aeronautics and Space Administration Chandra X-ray telescope(US).

    National Radio Astronomy Observatory(US)Karl G Jansky Very Large Array located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro. The VLA comprises twenty-eight 25-meter radio telescopes.

    Both jets clearly indicate that the 4.1-million-solar-mass Sgr A* is far from a sleeping giant.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 9:34 am on January 21, 2022 Permalink | Reply
    Tags: "Spend some time observing in Auriga - Photo Essay", , Astronomy Magazine, , ,   

    From Astronomy Magazine : “Spend some time observing in Auriga – Photo Essay” 

    From Astronomy Magazine

    January 11, 2022
    Michael E. Bakich

    With three Messier objects and loads of other bright targets, the Charioteer has a lot to offer.

    1
    Credit: Richard Talcott and Roen Kelly/Astronomy.

    The constellation Auriga (pronounced or-EYE-guh) the Charioteer, a star pattern known by this name for several thousand years, is easy to recognize primarily because of its brightest star, Capella (Alpha [α] Aurigae). This luminary is the sixth-brightest nighttime star and shines with an intense yellow light. The constellation’s Beta star, magnitude 1.9 Menkalinan, is 40th brightest.

    The Charioteer is visible in the evening from mid-autumn through winter in the Northern Hemisphere. Its center lies at R.A. 6h01m and Dec. 42° north. Auriga ranks 21st in size out of the 88 constellations, covering 657.44 square degrees (1.59 percent) of the sky. Its size is a bit of a hindrance to its visibility, however. It lies in the middle of the constellation ladder (43rd) in terms of overall brightness.

    The best date each year to see Auriga is December 21, when it stands opposite the Sun in the sky and reaches its highest point at local midnight. With respect to visibility, anyone living north of latitude 34° south can see the entire figure at some time during the year. And it’s completely invisible only to those who live at latitudes south of 62° south.

    Auriga contains three Messier objects (all open clusters) and several other open clusters and emission nebulae. Because it lies along the Milky Way, it doesn’t contain any galaxies. As you can see, however, lots of targets lie within its borders for you to point a telescope at. Good luck!

    Auriga targets

    2
    Credit: Anthony Ayiomamitis.

    Open cluster NGC 2281 glows at magnitude 5.4 and measures 14′ across. It lies 0.8° south-southwest of magnitude 5.0 Psi^⁷ (ψ^⁷) Aurigae. Through a 4-inch scope at 100x, you’ll spot two dozen stars. Four stars forming a parallelogram sit at the center of the cluster.

    3
    Credit: Jaspal Chadha.

    NGC 1664 is an attractive open cluster 2° west of magnitude 3.0 Epsilon (ε) Aurigae. It glows at magnitude 7.6 and spans 18′. A 4-inch scope at 100x reveals three dozen stars. The background star field is rich, but you’ll have no trouble picking out the cluster.

    4
    Credit: Martin C. Germano.

    NGC 1778 is a magnitude 7.7 open cluster with a diameter of 8′. You’ll find it 2° east-southeast of magnitude 5.1 Omega (ω) Aurigae. Through a 4-inch scope, you’ll see two dozen stars unevenly spread across this cluster’s face. Double the aperture to 8 inches, and you’ll raise that star count to 50.

    5
    Credit: Martin C. Germano.

    Barnard 29 is a dark nebula that lies 2.4° southeast of magnitude 2.7 Iota (ι) Aurigae. Through a 12-inch scope, B29 appears as a gray, mottled region that blends gradually into its starry surroundings. The darkest area appears 15′ across.

    6
    Credit: Alistair Symon.

    The Flaming Star Nebula (IC 405) appears as a dim 30′ by 20′ wisp of light. To observe it, first find AE Aurigae, which lies 4.2° east-northeast of Iota. Through a 6-inch scope, the nebula appears triangular.

    7
    Credit: Martin C. Germano.

    Open cluster NGC 1857 sits 0.8° south-southeast of magnitude 4.7 Lambda (λ) Aurigae. It glows at magnitude 7.0 and measures 5′. Through an 8-inch scope, you’ll see 25 stars around 13th magnitude. The exception is SAO 57903, a magnitude 7.4 yellow star at the center.

    8
    Credit: Mark Hanson.

    IC 410 is a large (40′ by 30′) emission nebula 2.4° west-northwest of magnitude 4.7 Chi (χ) Aurigae. The nebulosity glows brightest in an area 5′ in diameter on the northwestern edge. Use a 12-inch scope with an Oxygen-III filter and this object will knock your socks off.

    9
    Credit: Martin C. Germano.

    NGC 1907 is a magnitude 8.2 open cluster that spans 6′. A 4-inch scope at 100x shows about a dozen stars. Use a low-power eyepiece and you’ll sweep up an even-brighter open cluster: M38, 0.5° to the north-northeast.

    10
    Credit: Anthony Ayiomamitis.

    The Starfish Cluster (Messier 38) is the westernmost and faintest (magnitude 6.4) of the three Messier open clusters in this constellation. A 4-inch scope will reveal three dozen stars in an area 20′ across.

    11
    Al and Andy Ferayomi/Adam Block/The National Optical Astronomy Observatory (US)/The Association of Universities for Research in Astronomy (AURA)(US)/The National Science Foundation (US).

    Emission nebula NGC 1931 sits 0.8° east-southeast of magnitude 5.1 Phi (ϕ) Aurigae. An 8-inch scope at 200x shows the nebula, which spans 4′. It orients northeast to southwest and shows non-uniform brightness across its face.

    12
    Credit: Anthony Ayiomamitis.

    The Pinwheel Cluster (Messier 36) is the least spectacular of the Messier trio in Auriga. At magnitude 6.0, however, it still outshines 99.99 percent of the sky’s star clusters. Through a 4-inch scope, you’ll see several dozen stars strewn across an area 12′ wide.

    13
    Credit: Anthony Ayiomamitis.

    The Salt and Pepper Cluster (Messier 37) displays an even distribution of stars — a rarity in open clusters. A 3-inch scope reveals 50 stars. Through a 10-inch scope, you’ll count 200, and a 16-inch will reveal 500. M37 glows at magnitude 5.6 and is 20′ across.

    14
    Credit: Martin C. Germano.

    NGC 2126 lies midway between magnitude 1.9 Menkalinan (Beta [β] Aurigae) and magnitude 3.7 Delta (δ) Aurigae. It glows at magnitude 10.2 and spans 6′. Through a 6-inch telescope, you’ll see about 20 stars. The magnitude 6.0 star SAO 40801 lies 3′ northeast of the cluster.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 12:17 pm on January 14, 2022 Permalink | Reply
    Tags: "Don’t Look Up!", "How prepared is Earth for an asteroid collision?", Astronomy Magazine, Space based asteroid missions,   

    From Astronomy Magazine : “How prepared is Earth for an asteroid collision?” 

    From Astronomy Magazine

    December 20, 2021 [Just today in social media.]
    Corey S. Powell

    The National Aeronautics and Space Agency(US) and other world space agencies have been studying this possibility and the forecast for near-earth celestial objects for years. Their efforts helped inform the new film Don’t Look Up!

    1
    muratart/Shutterstock.

    Contrary to what you may have read, Earth will not be devastated by the asteroid Apophis on April 13, 2029. Neither will Bennu, a 1/3-mile-wide pile of flying space rubble, strike us on Sept. 24, 2182. Every single scare story out there warning of an impending celestial collision is just that, a scary tale. At the same time, it is inevitable that such an impact will eventually occur — and when it does, the event could generate vast firestorms, tsunamis and extinctions.

    That is the asteroid paradox, explains Amy Mainzer, a planetary-defense expert at The University of Arizona’s (US) Lunar and Planetary Laboratory: The odds of a major impact in any given year are minuscule, but the potential consequences are enormous. Further confounding things, the smaller the impact, the more likely it is to occur and the more difficult it is to predict. All those variables make it intensely challenging for scientists like Mainzer to assess asteroid risks in a useful way, and then to communicate that risk to the public. “You don’t need to run out and buy asteroid insurance,” she says. “But you don’t want to completely ignore the problem either.”

    Mainzer has been pondering these issues a lot lately in her role as the science advisor for Don’t Look Up!, a new film directed by Adam McKay (Vice, The Big Short, Anchor Man). The dark-satire film portrays a chaotic, confused global response to news that a comet is on a collision course with our planet. (Comets and asteroids pose similar hazards, but the filmmakers chose a comet for its greater drama.) The movie skewers, in wincingly believable ways, the powerful human desire not to believe in invisible dangers until they are right upon us.

    McKay conceived Don’t Look Up! as a metaphor for climate change, but it also literally depicts the asteroid-detection problems that Mainzer has spent her career attempting to solve. “The first thing I want to tell people is that we don’t know of anything that’s headed on a collision course. This is a science-fiction movie,” she says.

    Full disclosure is built into the way space-science works. The Center for Near-Earth Object (NEO) Studies at JPL/Caltech-NASA(US) uses orbit-simulation software called Sentry II to assess the danger posed by any newfound asteroid. In less than one hour, it can calculate an object’s exact odds of impact within the next hundred years — down to the sliver of 1 in 10 million. The resulting database is openly accessible. You can see for yourself that no large objects have any significant probability of landing on our heads within a human lifetime.

    That reassurance comes with a significant caveat, though, because current asteroid surveys are far from complete. Mainzer has been working to remedy that as the principal investigator on NEOWISE, a repurposed NASA infrared space telescope that now scans the sky for previously unknown space rocks.

    National Aeronautics and Space Administration(US) Wise/NEOWISE Telescope.

    For years, asteroid hunters have campaigned for a modern successor to complete the job. This past June, NASA formally authorized the much more powerful NEO Surveyor, with Mainzer reprising her role as head surveyor.
    NEO Surveyor Infrared Space Telescope depiction

    “March 26, 2026 is our target date on the launch pad,” she says.

    By the mid 2030s, NEO Surveyor should have found 90 percent of the potentially hazardous asteroid more than 140 meters (460 feet) in diameter; astronomers focus on that size cutoff because such objects are small enough to slip through current surveys but large enough to cause significant regional damage. For even bigger asteroids, capable of causing global destruction on Earth, the coverage should approach 100 percent. Plug all of those newfound asteroids through the Sentry II software, and we will have a near-complete database of every large object that could potentially menace our planet over the next century. That will be a huge step beyond where we are now.

    Simulating an impact

    Scientists today run into their own asteroid paradox. There is no objective formula showing what level of risk requires action, nor what action would be desirable. A critical part of unwinding the paradox is the complicated, unsexy process of analysis: If NEO Survey or one of the other asteroid surveys uncovers a potentially hazardous object, scientists need to crunch a lot of data to figure out exactly how big and how dangerous the object is. And they need to do the job as quickly as possible, so we have maximum time to prepare a response.

    To hone that process, NASA has sponsored a series of planetary-defense simulations in which scientists pretend they have discovered a new Earth-threatening asteroid. A 2021 exercise, coordinated last spring by Vishnu Reddy at the University of Arizona, imagined that an asteroid similar to Apophis really was on a collision course with us, and then set the participants loose trying to understand what was happening. The simulation culminated with a deadly impact in the Czech Republic, and was scary enough that the associated website and press releases are plastered with “EXERCISE” and “FICTIONAL” warnings.

    People focus on the Armageddon-style heroics of sending a mission to blow the asteroid to bits, “but if you don’t have the analysis tools in place, it’s all kind of a moot point,” Mainzer says. “Are you looking at a situation where the only thing you can do is move people out of the way? Or do you have enough flexibility to mitigate the risk?”

    Asteroid deflection scheduled

    Fortunately, the world’s space agencies are stepping up their efforts to learn how to move a dangerous asteroid out of the way. Next year, NASA’s DART spacecraft (Double Asteroid Redirection Test) will ram headlong into a 500-foot (160-meter) asteroid called Dimorphos, the first test of asteroid deflection.
    National Aeronautics Space Agency(US) DART in space depiction.

    National Aeronautics and Space Administration(US) NASA Double Asteroid Redirection Test (DART) Mission (US) schematic.

    About four years later, the European Space Agency’s Hera spacecraft will swing by to make a close study of DART’s effect on Dimorphos.

    European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)’s Hera spacecraft depiction.

    The joint missions will vastly improve our knowledge of what asteroids are like on the inside and what it will take to move a risky one out of the way.

    Even then, risk itself remains a slippery concept, one that often means something quite different to scientists than it does to the public. This disconnect is a theme that Don’t Look Up! explores in biting detail. In the real world, would the public trust scientists’ recommendations to act against a dangerous asteroid, even if the calculated risk sounds low and the cost of a deflection mission runs into the billions of dollars? Mainzer worries about the obstacles created by scientific jargon; McKay points to the many people who dismiss expert analysis of the pandemic and climate change, even in the face of events unfolding all around.

    On the flip side, message boards and online forums like Quora are full of questions from people who doubt that scientists would reveal an Earth-threatening object if they found one. Mainzer laughs ruefully at the possibility. “Most scientists that I’ve ever met, the challenge is getting them to stop talking,” she says. “The problem is that scientists tell us things that we may not want to hear. But we need to hear them.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 11:40 am on January 14, 2022 Permalink | Reply
    Tags: "Are we ready for the next big solar storm?", Astronomy Magazine, ,   

    From Astronomy Magazine : “Are we ready for the next big solar storm?” 

    From Astronomy Magazine

    January 4, 2022
    Joshua Rapp Learn

    The biggest geomagnetic storm in recorded history happened more than 150 years ago. Now, we’re entering yet another period of solar maximum.

    1
    Lia Koltyrina/Shutterstock.

    It was just another September night in 1859 when Richard Carrington and Richard Hodgson witnessed a remarkable event. The British astronomers weren’t together, but both happened to be peering at the Sun through telescopes at the precise moment that a massive ejection spewed from the fiery star. Within a few days, others on Earth noticed colorful aurora streaking across the skies and telegraph lines — the advanced technology of the day in Europe and North America — erupting in sparks.

    The solar flare came to be known as The Carrington Event, named after one of the two astronomers who first described it. Despite occurring more than 150 years ago, it still stands as the strongest known geomagnetic storm (though we lack measurements to say precisely how big it was).

    Earth has felt the effects of a few significant geomagnetic storms since then, all of which caused power blackouts and satellite damage. As a result, power companies and satellite manufacturers have built resistance into our technology. But what would happen if another Carrington Event-level solar flare occurred today? Would we be ready for it?

    According to Alexa Halford, an associate chief of the Heliophysics Science Division at The Goddard Space Flight Center-NASA (US), the answer is a cautious affirmative. “There’s still a lot to learn, she says, but we’ve had success.”

    Decades of learning

    Flares occur when electromagnetic radiation erupts from the Sun. These bursts often last a few minutes, though they are sometimes longer. They are sometimes associated with coronal mass ejections [CME’s], which blow out gas material and magnetic fields. But not every solar flare or coronal mass ejection will have an impact on Earth; it depends on both the size of the burst and the direction it’s heading. If a solar flare occurs on the far side of the Sun, for example, it’s unlikely to affect us.

    Even if it does happen on the near side, the direction of the burst often misses us — as we’re quite far away and a relatively small target compared to the Sun. This occurred in 2001, for example, when one of the largest solar flares in recorded history exploded into a coronal mass ejection at a speed of about 4.5 million miles per hour. Luckily, it swept by us on its way into space.

    Technology was relatively simple in 1859 when the Carrington Event occurred, but it still had a big impact on telegraph lines. At the time, people had to unplug the wires to stop the sparks erupting from them. But they remained partly functional, thanks to the particles ejected from the flare that struck the current in the lines. “They actually had to unplug them, and they still had enough energy and currents to run for a period of time,” Halford says.

    There have been earlier solar flares whose impacts were felt on Earth, of course. A Sun storm that occurred in 993 C.E. left evidence on tree trunks that archaeologists still use today to date ancient wood materials, such as the brief Viking settlement in the Americas. Another significant solar flare occurred during World War I. It wasn’t as large as the Carrington Event, but it still confused detection equipment. Technicians believed bombs were dropping when it was actually interference from the flare hitting the magnetosphere, Halford says.

    A large coronal mass ejection recently struck Earth in March 1989, and the resulting geomagnetic storm caused serious havoc on Earth. The flare knocked out the power grids in Quebec and parts of New England, as the utility company Hydro-Quebec was down for nine hours. Power transformers even melted due to an overloading of electricity in the grid.

    Safety measures

    That 1989 event finally got the attention of infrastructure planners. “Those are the kinds of things that we have really learned our lesson from,” Halford says. Power companies began building safety measures, such as tripwires, into the electricity grid to stop cascading failure. If power increases too quickly, these tripwires are programmed to switch off so that damage is limited and transformers don’t burn out as they did in 1989.

    Geomagnetic storms can also cause bit flips, surface charging or internal charging to satellites orbiting our planet — all things that occurred this October when a solar flare produced a coronal mass ejection and a geomagnetic storm that hit Earth. Satellites are particularly susceptible because they don’t benefit from the relative protection of our atmosphere. But most of the satellites launched in the past two decades have been built robustly enough that they are resistant to overcharging.

    The bit flips occur when ionized particles from the solar outbursts switch the function of memory bits. This can cause big problems for GPS satellites, which effect everything from navigation to precision drilling. Even banking relies on GPS satellite to dictate the timing of transactions. “That kind of failure would really hurt the economy,” Halford says. “It’s important and definitely something we should be worried about.”

    While satellites are now built more robustly, she adds that it’s unlikely a storm would take out enough GPS satellites to cause many larger problems, though. These problems can also sometimes be easily fixed by power cycling, or simply by restarting the affected device. The October flare caused some minor problems, but the Federal Aviation Administration didn’t report any major navigation issues, Halford says.

    Positive impacts

    Not all impacts of a large solar flare would necessarily be negative. When these events occur, they thicken the density of Earth’s upper atmosphere. In effect, the atmosphere rises in altitude for a short period. This can impact the orbits of satellites, potentially causing problems, but it can also affect the orbits of space debris floating around up there. The extra drag could cause this junk to fall into orbit and burn up.

    “You want some storms so we can naturally get rid of some of the debris,” Halford says. But it might be a double-edged sword, as the event could cause the orbital decay of operating equipment up there as well.

    Another potentially positive effect for Earthlings living closer to the equator is the increased visibility of aurora. Northern lights and southern lights are caused when solar particles enter the atmosphere and collide with gas particles. This usually happens at the poles, where the magnetic field is weaker. But during solar flares, more of the particles make it through the atmosphere. Aurora borealis was recently visible in New York during the October solar storm.

    These opportunities will only increase as we approach a period of solar maximum, which is when we see the greatest period of solar activity every 11 years or so. “The next few years should be really exciting because we will have a lot more chances to see the aurora,” Halford says.

    This might also be a likely time for another big solar flare to strike. According to Halford, it’ll be a chance to see how well our safety measures and precautions can deal with this influx of solar particles — but don’t hold your breath. A study published in 2019 [Scientific Reports] found the chance of a Carrington-like event occurring before 2029 is less than 1.9 percent. “A Carrington Event is one of those kinds of things that you kind of want to have happen,” Halford says, “because we think we can weather it.”

    See the full article here3 .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
  • richardmitnick 12:32 pm on January 7, 2022 Permalink | Reply
    Tags: "How the GOODS fields expanded our cosmic boundaries", Astronomers threw an enormous amount of resources at two small patches in the sky in search of the faintest and most distant galaxies., Astronomy Magazine, , , , COSMOS (Cosmological Evolution Survey), Galaxy Evolution from Morphology and Spectral Energy Distributions, Hubble Deep Field, Hubble Ultra-Deep Field, , , The GOODS field, The Great Observatories Origins Deep Survey   

    From Astronomy Magazine : “How the GOODS fields expanded our cosmic boundaries” 

    From Astronomy Magazine

    December 22, 2021 [Just today in social media]
    Jure Japel

    Astronomers threw an enormous amount of resources at two small patches in the sky in search of the faintest and most distant galaxies.

    1
    An excerpt of the Hubble Ultra-Deep Field, a part of the GOODS-South field.
    Credit: H. Teplitz and M. Rafelski The National Aeronautics and Space Agency(US), The European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU), The Caltech IPAC-Infrared Processing and Analysis Center (US); A. Koekemoer-The Space Telescope Science Institute (US), R. Windhorst-The Arizona State University (US)); and Z. Levay (STScI)

    In the northern constellation Ursa Minor lies a small and inconspicuous patch of sky devoid of prominent stars or galaxies. A similar, twin patch lies in the southern sky in the direction of Fornax. The two regions, known among astronomers as the GOODS fields, don’t seem like much at first glance. But make no mistake about it — the fields have redefined our understanding of the young universe.

    That infant universe looked much different than it does today. The universe has been expanding and evolving for billions of years. What gave rise to the rich assemblage of galaxies of different shapes and sizes? Did galaxies always look like they do today? To answer such questions, astronomers follow a simple recipe: Observe very distant galaxies. Because light travels at a finite speed, we see distant objects as they were in the past. Unfortunately, distant galaxies are very faint.

    And here is where the GOODS fields come in. Astronomers threw a large amount of resources into the fields to get the most comprehensive look into the past. GOODS stands for The Great Observatories Origins Deep Survey. “We came up with the GOODS acronym because we wanted to deliver the goods,” jokes Mauro Giavalisco, an astronomer at The University of Massachusetts-Amherst (US).

    The idea for the fields didn’t just pop out of nowhere. Like many other success stories in science, it all started with a cup of coffee.

    The first of them all: Hubble Deep Field

    NASA Hubble Deep Field

    In 1994, the Hubble Space Telescope (HST) was on fire.

    National Aeronautics and Space Administration(US)/European Space Agency [Agence spatiale européenne] [Europäische Weltraumorganisation](EU) Hubble Space Telescope.

    Thought it had a rough start plagued by defective mirrors, after a shuttle service mission installed corrective optics-COSTAR, it finally started producing sharp images of planets, star systems, and galaxies.

    NASA COSTAR installation

    NASA COSTAR

    Robert Williams, then the director of the Space Telescope Science Institute in Baltimore, spent every morning drinking coffee and discussing the latest science results with a group of young scientists. The first deep HST images of galaxies made an especially strong impression on the group. Williams realized that, with a proper program, HST could look farther back in time than ever before. The idea of a deep field — a view constructed of images that represent the equivalent of extremely long exposures — began to emerge.

    The idea was risky: They didn’t know what, if anything, this deep field would reveal. And because HST was in high demand, it would be difficult to get the needed time for the program through the usual peer-review process. To make the project a reality, Williams made some shrewd moves. As a director, he had the discretion to dedicate a substantial amount of the observing time to the project. Furthermore, he decided to make the data public immediately after acquisition, starting a proud tradition of so-called treasury projects.

    At the end of 1995, HST observed a tiny spot in the sky for ten days straight. The combined image, known as the Hubble Deep Field, was spectacular. An area of about 2.6 arcminutes on a side contained roughly 3,000 galaxies, some of them emitting light when the universe was less than 2 billion years old.

    But why stop with the Hubble Deep Field? The success of the program quickly spurred thoughts of new, deeper fields.

    2
    The GOODS field has become such a standard that the larger GEMS (Galaxy Evolution from Morphology and Spectral Energy Distributions) field was also centered on it. This comparison of various deep fields taken by Hubble also includes the Hubble Ultra Deep Field (HUDF) and COSMOS (Cosmological Evolution Survey).
    NASA, ESA and Z. Levay (STScI)

    3
    COSMOS 3D dark matter map. Credit: NASA/ESA Hubble.

    4
    A team of astronomers studied over 1400 galaxies snapped by Hubble in the COSMOS survey, to test the hypothesis that galactic mergers trigger active galactic nuclei (AGN). In order to make this a blind test, the team modelled and removed the active nucleus (which normally appears as a bright spot) from each galaxy, and then cosmetically added a similar mark to the galaxies without an AGN, to make them visually indistinguishable. This explains the black dot visible near the centre of each of these images.

    They then categorised the galaxies, according to whether they showed no sign of recent mergers (top), minor signs (middle row) or clear signs of disruption from a recent merger (bottom).
    Analysing these results, they found that galaxies with active nuclei (left) and those with inactive nuclei (right) showed no statistically significant difference in the proportion that had undergone mergers. This means that processes other than galactic mergers must trigger AGN activity.
    Date 5 January 2011
    Source http://www.spacetelescope.org/images/heic1101a/
    Author NASA, ESA, M. Cisternas-The MPG Institute for Astronomy [MPG Institut für Astronomie](DE)

    NASA Hubble Ultra Deep Field. National Aeronautics Space Agency(US)/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU) NASA/ESA Hubble Space Telescope(US).

    Everyone gets the GOODS

    While astronomers have designated several deep fields in the sky over time, the GOODS fields stand out due to the repeated attention they received. Every time astronauts installed a new, more powerful camera on HST, the telescope was turned towards the fields to produce progressively deeper images.

    Hubble WFPC2 no longer in service.
    National Aeronautics Space Agency(USA) European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Hubble Wide Field Camera 3.

    National Aeronautics Space Agency(US)/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU) Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope(US).

    National Aeronautics Space Agency (US) Cosmic Origins Spectrograph.

    X-ray, infrared, and radio telescopes spent many hours staring at the fields, and so did the largest ground-based telescopes. The investment of time in the two fields, each about one-quarter the size of the Full Moon, was enormous.

    The idea to make high-quality data immediately available to everyone encouraged committees to award huge amounts of observing time and resources to study the fields. “The public observations turned out to be the winning paradigm for the investigation of the high redshift science,” says Giavalisco.

    The observations of the fields led to a massive number of studies and results. Scientists got a clear view of how galaxy characteristics changed over time. “People thought early galaxies were large and diffuse, but in fact, they were small and compact,” says Giavalisco. It turned out that galaxies formed stars more enthusiastically in the past. Carefully thought-out observations of the fields discovered many distant supernovae, leading to an improved understanding of the accelerated expansion of the universe. Deep X-ray observations revealed distant active galactic nuclei. The list is endless.

    The fields also contain some real astrophysical gems. For example, the northern GOODS field hosts the most distant object ever discovered: The galaxy named GN-z11 radiated the light we see today only 400 million years after Big Bang.

    4
    The northern GOODS field hosts the most distant galaxy ever discovered. The galaxy GN-z11 has about one percent of the Milky Way’s mass but forms stars approximately 20 times as fast.
    NASA, ESA, and P. Oesch-Yale University (US)

    James Webb Space Telescope continues the legacy

    National Aeronautics Space Agency(US)/European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) James Webb Infrared Space Telescope(US) annotated. Scheduled for launch in 2011 delayed to October 2021 finally launched December 25, 2021.

    Unsurprisingly, the long-awaited James Webb Space Telescope (JWST), launched Dec. 25, 2021 [11 years late] will also take a long, good look at the GOODS fields. “If one were to decide where could you get the most bang for your dollar, it would be in the GOODS fields because there’s already so much other information,” says Marcia Rieke, an astronomer at The University of Arizona (US) and the principal investigator of JWST’s NIRspec spectrograph.

    European Space Agency [Agence spatiale européenne](EU)Webb NIRspec.

    Rieke co-leads the JWST Advanced Deep Extragalactic Survey (JADES), a large program that will observe the two GOODS fields for almost 800 hours. The telescope will simultaneously use two instruments to acquire infrared images and spectra of the galaxies in the fields.

    The JADES program will continue the quest to understand galaxy evolution. JWST will observe the most distant galaxies, perhaps even the first stars. It will trace galaxy morphologies over time and unveil the universe’s chemical evolution. The puzzling origin of supermassive black holes in a young universe is also on the JWST’s agenda.

    Perhaps the most exciting part of staring into the GOODS fields is the unknown. Every time a new instrument or telescope looked at the fields, new and unexpected things emerged. There is no reason to believe that the same won’t happen with JWST — and its successors.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Astronomy is a magazine about the science and hobby of astronomy. Based near Milwaukee in Waukesha, Wisconsin, it is produced by Kalmbach Publishing. Astronomy’s readers include those interested in astronomy and those who want to know about sky events, observing techniques, astrophotography, and amateur astronomy in general.

    Astronomy was founded in 1973 by Stephen A. Walther, a graduate of The University of Wisconsin–Stevens Point (US) and amateur astronomer. The first issue, August 1973, consisted of 48 pages with five feature articles and information about what to see in the sky that month. Issues contained astrophotos and illustrations created by astronomical artists. Walther had worked part time as a planetarium lecturer at The University of Wisconsin–Milwaukee (US) and developed an interest in photographing constellations at an early age. Although even in childhood he was interested to obsession in Astronomy, he did so poorly in mathematics that his mother despaired that he would ever be able to earn a living. However he graduated in Journalism from the University of Wisconsin Stevens Point, and as a senior class project he created a business plan for a magazine for amateur astronomers. With the help of his brother David, he was able to bring the magazine to fruition. He died in 1977.

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: