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  • richardmitnick 10:55 am on May 31, 2019 Permalink | Reply
    Tags: , , , , NASA/NICER on the ISS, The map includes data from the first 22 months of NICER’s science operations.   

    From NASA: NICER’s Night Moves Trace the X-ray Sky” 

    NASA image
    From NASA

    May 30, 2019
    By Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Media contact: Claire Andreoli
    claire.andreoli@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    NASA/NICER on the ISS

    In this image, numerous sweeping arcs seem to congregate at various bright regions. You may wonder: What is being shown? Air traffic routes? Information moving around the global internet? Magnetic fields looping across active areas on the Sun?

    In fact, this is a map of the entire sky in X-rays recorded by NASA’s Neutron star Interior Composition Explorer (NICER), a payload on the International Space Station. NICER’s primary science goals require that it target and track cosmic sources as the station orbits Earth every 93 minutes. But when the Sun sets and night falls on the orbital outpost, the NICER team keeps its detectors active while the payload slews from one target to another, which can occur up to eight times each orbit.

    The map includes data from the first 22 months of NICER’s science operations. Each arc traces X-rays, as well as occasional strikes from energetic particles, captured during NICER’s night moves. The brightness of each point in the image is a result of these contributions as well as the time NICER has spent looking in that direction. A diffuse glow permeates the X-ray sky even far from bright sources.

    1
    This image of the whole sky shows 22 months of X-ray data recorded by NASA’s Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station during its nighttime slews between targets. NICER frequently observes targets best suited to its core mission (“mass-radius” pulsars) and those whose regular pulses are ideal for the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment. One day they could form the basis of a GPS-like system for navigating the solar system.

    The prominent arcs form because NICER often follows the same paths between targets. The arcs converge on bright spots representing NICER’s most popular destinations — the locations of important X-ray sources the mission regularly monitors.

    “Even with minimal processing, this image reveals the Cygnus Loop, a supernova remnant about 90 light-years across and thought to be 5,000 to 8,000 years old,” said Keith Gendreau, the mission’s principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re gradually building up a new X-ray image of the whole sky, and it’s possible NICER’s nighttime sweeps will uncover previously unknown sources.”

    NICER’s primary mission is to determine the size of dense remains of dead stars called neutron stars — some of which we see as pulsars — to a precision of 5%. These measurements will finally allow physicists to solve the mystery of what form of matter exists in their incredibly compressed cores. Pulsars, rapidly spinning neutron stars that appear to “pulse” bright light, are ideally suited to this “mass-radius” research and are some of NICER’s regular targets.

    Other frequently visited pulsars are studied as part of NICER’s Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) experiment, which uses the precise timing of pulsar X-ray pulses to autonomously determine NICER’s position and speed in space. It’s essentially a galactic GPS system. When mature, this technology will enable spacecraft to navigate themselves throughout the solar system — and beyond.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:26 am on February 20, 2019 Permalink | Reply
    Tags: , , , , MSX-NASA Modulated X-ray Source, NASA NavCube, NASA Set to Demonstrate X-ray Communications in Space, NASA XCOM, NASA/NICER on the ISS,   

    From NASA Goddard Space Flight Center: “NASA Set to Demonstrate X-ray Communications in Space” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    Feb. 19, 2019
    Lori Keesey
    NASA’s Goddard Spaceflight Center

    NASA Modulated X-ray Source, a key component in NASA’s first-ever demonstration of X-ray communication in space

    A new experimental type of deep space communications technology is scheduled to be demonstrated on the International Space Station this spring.

    Currently, NASA relies on radio waves to send information between spacecraft and Earth. Emerging laser communications technology offers higher data rates that let spacecraft transmit more data at a time. This demonstration involves X-ray communications, or XCOM, which offers even more advantages.

    X-rays have much shorter wavelengths than both infrared and radio. This means that, in principle, XCOM can send more data for the same amount of transmission power. The X-rays can broadcast in tighter beams, thus using less energy when communicating over vast distances.

    NASA XCOM

    If successful, the experiment could increase interest in the communications technology, which could permit more efficient gigabits-per-second data rates for deep space missions. Gigabits per second is a data transfer rate equivalent to one billion bits, or simple binary units, per second. These extremely high-speed rates of data transfer are not currently common, but new research projects have pushed computing capability toward this range for some technologies.

    “We’ve waited a long time to demonstrate this capability,” said Jason Mitchell, an engineer at NASA’s Goddard Spaceflight Center in Greenbelt, Maryland, who helped develop the technology demonstration, which relies on a device called the Modulated X-ray Source, or MXS.

    “For some missions, XCOM may be an enabling technology due to the extreme distances where they must operate,” Mitchell said.

    Perhaps more dramatically, at least as far as human spaceflight is concerned, X-rays can pierce the hot plasma sheath that builds up as spacecraft hurdle through Earth’s atmosphere at hypersonic speeds. The plasma acts as a shield, cutting off radio frequency communications with anything outside the vehicle for several seconds — a nail-biting period of time dramatically portrayed in the movie, Apollo 13. No one has ever used X-rays in a communications system, though, so other applications not yet conceived could emerge, Mitchell said.

    “Our goal for the immediate future is finding interested partners to help further develop this technology,” Mitchell said.

    Encoding Digital Bits

    To demonstrate this new communications technology, NASA will use the MXS to generate rapid-fire X-ray pulses. Operated by another Goddard-developed computing and navigation technology called NavCube, MXS will turn on and off many times per second while encoding digital bits for transmission.

    NASA’s NavCube

    From the experimental payload, the MXS device will then send the encoded data via the modulated X-rays to detectors on the Neutron-star Interior Composition Explorer, or NICER, which is located 165 feet away — about the width of a football field — on the space station. In this way, NICER becomes the receiver of a one-way X-ray signal.

    NASA NICER on the ISS


    NASA/NICER on the ISS

    3
    NASA’s first-ever demonstration of X-ray communication will occur on the International Space Station. This image shows the locations of the Modulated X-ray Source and the Neutron star Interior Composition Explorer, or NICER, which are critical to the demonstration. Credits: NASA

    Although the first XCOM test will involve the transmission of GPS-like signals, Mitchell said the team may attempt to transmit something more complicated after the initial attempt.

    “It’s important is that we transmit a known code we can identify to make sure NICER receives the signal precisely the way we sent it,” Mitchell said.

    Although primarily built to gather data about the densest objects in the universe — neutron stars and their pulsating next-of-kin, known as pulsars — NICER was also designed to demonstrate advanced technology. In addition to the XCOM demonstration, the mission proved the effectiveness of X-ray navigation in space, showing in 2017 that pulsars could be used as timing sources for navigational purposes.

    During that two-day demonstration, which the NICER team carried out with an experiment called Station Explorer for X-ray Timing and Navigation Technology, or SEXTANT, the mission gathered 78 measurements from four millisecond pulsars. The team fed that data into onboard algorithms to autonomously stitch together a navigational solution that revealed the location of NICER in its orbit around Earth as a space station payload. Within eight hours of starting the experiment, the system converged on a location within the targeted 6.2 miles and remained well below that threshold for the rest of the experiment.

    NICER’s ability to carry out science and demonstrate emerging, revolutionary technologies has captured the attention of those planning NASA’s next era of human spaceflight. Missions that perform multiple functions are now considered a model, said Jake Bleacher, lead exploration scientist responsible for identifying areas where Goddard scientists can support human exploration of the Moon and Mars.

    Technology Heritage

    The idea to use X-rays to communicate and navigate originated more than a decade ago when NICER Principal Investigator Keith Gendreau began work on enabling technologies for a proposed black hole imager aimed at directly imaging the event horizon of a supermassive black hole or the point of no return where nothing — neither particles nor photons — can escape.

    The idea was to establish a constellation of precisely aligned spacecraft that would in essence create an X-ray interferometer, an instrument used to measure displacements in objects. He conceived the idea of using X-ray sources as beacons to enable highly precise relative navigation. Using research and development funding, he developed the MXS.

    Gendreau then reasoned that if he could modulate X-rays through a modulator, he could also communicate, thus giving birth to the NICER three-in-one mission concept.

    The XCOM demonstration is managed by NASA’s Space Communications and Navigation program within the Human Exploration and Operations Mission Directorate. NICER is an Astrophysics Mission of Opportunity within the Explorers program. The Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation.

    For more Goddard technology news, go to: https://www.nasa.gov/sites/default/files/atoms/files/winter_2019_final_web_version.pdf

    For more on SCaN’s advanced communications and navigation technology program, go to: http://nasa.gov/scan

    See the full article here.


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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 12:09 pm on January 31, 2019 Permalink | Reply
    Tags: , , , , , , NASA/NICER on the ISS, NASA’s NICER Mission Maps ‘Light Echoes’ of New Black Hole   

    From NASA: “NASA’s NICER Mission Maps ‘Light Echoes’ of New Black Hole” 

    NASA image
    From NASA

    Jan. 30, 2019

    Jeanette Kazmierczak
    jeanette.a.kazmierczak@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    NASA NICER on the ISS


    NASA/NICER on the ISS

    1
    In this illustration of a newly discovered black hole named MAXI J1820+070, a black hole pulls material off a neighboring star and into an accretion disk. Above the disk is a region of subatomic particles called the corona. Credit: Aurore Simonnet and NASA’s Goddard Space Flight Center

    Scientists have charted the environment surrounding a stellar-mass black hole that is 10 times the mass of the Sun using NASA’s Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station. NICER detected X-ray light from the recently discovered black hole, called MAXI J1820+070 (J1820 for short), as it consumed material from a companion star. Waves of X-rays formed “light echoes” that reflected off the swirling gas near the black hole and revealed changes in the environment’s size and shape.

    “NICER has allowed us to measure light echoes closer to a stellar-mass black hole than ever before,” said Erin Kara, an astrophysicist at the University of Maryland, College Park and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who presented the findings at the 233rd American Astronomical Society meeting in Seattle. “Previously, these light echoes off the inner accretion disk were only seen in supermassive black holes, which are millions to billions of solar masses and undergo changes slowly. Stellar black holes like J1820 have much lower masses and evolve much faster, so we can see changes play out on human time scales.”

    A paper describing the findings, led by Kara, appeared in the Jan. 10 issue of Nature and is available online from [Nature].


    Watch how X-ray echoes, mapped by NASA’s Neutron star Interior Composition Explorer (NICER) revealed changes to the corona of black hole MAXI J1820+070.
    Credits: NASA’s Goddard Space Flight Center

    J1820 is located about 10,000 light-years away toward the constellation Leo. The companion star in the system was identified in a survey by ESA’s (European Space Agency) Gaia mission, which allowed researchers to estimate its distance.

    ESA/GAIA satellite

    Astronomers were unaware of the black hole’s presence until March 11, 2018, when an outburst was spotted by the Japan Aerospace Exploration Agency’s Monitor of All-sky X-ray Image (MAXI), also aboard the space station.

    JAXA MAXI on the ISS

    J1820 went from a totally unknown black hole to one of the brightest sources in the X-ray sky over a few days. NICER moved quickly to capture this dramatic transition and continues to follow the fading tail of the eruption.

    “NICER was designed to be sensitive enough to study faint, incredibly dense objects called neutron stars,” said Zaven Arzoumanian, the NICER science lead at Goddard and a co-author of the paper. “We’re pleased at how useful it’s also proven in studying these very X-ray-bright stellar-mass black holes.”

    A black hole can siphon gas from a nearby companion star into a ring of material called an accretion disk. Gravitational and magnetic forces heat the disk to millions of degrees, making it hot enough to produce X-rays at the inner parts of the disk, near the black hole. Outbursts occur when an instability in the disk causes a flood of gas to move inward, toward the black hole, like an avalanche. The causes of disk instabilities are poorly understood.

    Above the disk is the corona, a region of subatomic particles around 1 billion degrees Celsius (1.8 billion degrees Fahrenheit) that glows in higher-energy X-rays. Many mysteries remain about the origin and evolution of the corona. Some theories suggest the structure could represent an early form of the high-speed particle jets these types of systems often emit.

    Astrophysicists want to better understand how the inner edge of the accretion disk and the corona above it change in size and shape as a black hole accretes material from its companion star. If they can understand how and why these changes occur in stellar-mass black holes over a period of weeks, scientists could shed light on how supermassive black holes evolve over millions of years and how they affect the galaxies in which they reside.

    One method used to chart those changes is called X-ray reverberation mapping, which uses X-ray reflections in much the same way sonar uses sound waves to map undersea terrain. Some X-rays from the corona travel straight toward us, while others light up the disk and reflect back at different energies and angles.

    X-ray reverberation mapping of supermassive black holes has shown that the inner edge of the accretion disk is very close to the event horizon, the point of no return. The corona is also compact, lying closer to the black hole rather than over much of the accretion disk. Previous observations of X-ray echoes from stellar black holes, however, suggested the inner edge of the accretion disk could be quite distant, up to hundreds of times the size of the event horizon. The stellar-mass J1820, however, behaved more like its supermassive cousins.

    As they examined NICER’s observations of J1820, Kara’s team saw a decrease in the delay, or lag time, between the initial flare of X-rays coming directly from the corona and the flare’s echo off the disk, indicating that the X-rays traveled shorter and shorter distances before they were reflected. From 10,000 light-years away, they estimated that the corona contracted vertically from roughly 100 to 10 miles — that’s like seeing something the size of a blueberry shrink to something the size of a poppy seed at the distance of Pluto.

    “This is the first time that we’ve seen this kind of evidence that it’s the corona shrinking during this particular phase of outburst evolution,” said co-author Jack Steiner, an astrophysicist at the Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research in Cambridge. “The corona is still pretty mysterious, and we still have a loose understanding of what it is. But we now have evidence that the thing that’s evolving in the system is the structure of the corona itself.”

    To confirm the decreased lag time was due to a change in the corona and not the disk, the researchers used a signal called the iron K line created when X-rays from the corona collide with iron atoms in the disk, causing them to fluoresce. Time runs slower in stronger gravitational fields and at higher velocities, as stated in Einstein’s theory of relativity. When the iron atoms closest to the black hole are bombarded by light from the core of the corona, the X-ray wavelengths they emit get stretched because time is moving slower for them than for the observer (in this case, NICER).

    Kara’s team discovered that J1820’s stretched iron K line remained constant, which means the inner edge of the disk remained close to the black hole — similar to a supermassive black hole. If the decreased lag time was caused by the inner edge of the disk moving even further inward, then the iron K line would have stretched even more.

    These observations give scientists new insights into how material funnels in to the black hole and how energy is released in this process.

    “NICER’s observations of J1820 have taught us something new about stellar-mass black holes and about how we might use them as analogs for studying supermassive black holes and their effects on galaxy formation,” said co-author Philip Uttley, an astrophysicist at the University of Amsterdam. “We’ve seen four similar events in NICER’s first year, and it’s remarkable. It feels like we’re on the edge of a huge breakthrough in X-ray astronomy.”

    NICER is an Astrophysics Mission of Opportunity within NASA’s Explorer program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA’s Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 11:44 am on January 21, 2019 Permalink | Reply
    Tags: A huge flare from a black hole helps reveal how matter and energy are expelled, , , “Light echoes” — time lags between the x-ray light coming from two different areas around the black hole, , , , , MAXI J1820+070, NASA/NICER on the ISS   

    From Scientific American: “Erupting Black Hole Shows Intriguing ‘Light Echoes'” 

    Scientific American

    From Scientific American

    Jan 11, 2019
    Clara Moskowitz

    1
    A black hole called MAXI J1820+070 emitted a huge flare of X-ray light that astronomers monitored over time to study how black holes swallow and spit out matter. Photo: NASA’s Goddard Space Flight Center.

    A huge flare from a black hole helps reveal how matter and energy are expelled

    We tend to think black holes gobble up all the matter around them — but they can actually spew out as much as they suck in. And sometimes they seem to go downright crazy.

    Astronomers recently spotted one black hole, nearly 10,000 light-years from Earth, belching out an enormous explosion of x-ray light. Measurements of this tantrum have given scientists one of the clearest pictures yet of what happens when black holes erupt with energy. “One of our big questions is how do we go from this process of material flowing into the black hole to this process of flowing out?” says astronomer Erin Kara of the University of Maryland, College Park, lead author of a paper on the findings, published this week in Nature. “We know this is happening but we don’t understand how it works in detail.” Kara presented the discovery Wednesday at the American Astronomical Society’s annual meeting in Seattle.

    The outburst began on March 11, 2018, and quickly transformed a black hole that had been totally invisible to telescopes into one of the brightest objects (in terms of x-ray light) in the entire sky. The object, called MAXI J1820+070, was first spotted by the Monitor of All-sky X-ray Image (MAXI) experiment on the International Space Station. Another observatory on the station, the Neutron star Interior Composition Explorer (NICER), monitored the flare with near-daily observations over the next few months.

    JAXA MAXI on the ISS

    NASA/NICER on the ISS

    Not only did astronomers measure the black hole brightening extremely over this time, they also observed what they called “light echoes” — time lags between the x-ray light coming from two different areas around the black hole. Some light travels straight from a region called the corona, made of electrons and other charged particles close in to the black hole. Farther out and perpendicular to the corona is the “accretion disk” — a wider pancake of gas swirling around the hole and falling into it. Other light comes out of the corona and bounces off this disk, arriving at the NICER detectors later. As NICER watched the eruption, the time between echoes became shorter and shorter, indicating the distance between the disk and corona was shrinking. The scientists had evidence the boundaries of the disk were not changing, so they concluded the corona itself must be getting shorter and thus light did not have to travel so far to reach the disk. “This is the clearest detection to date of these light echoes off of the gas falling into a stellar-mass black hole in our own galaxy,” says Dan Wilkins, an astrophysicist at Stanford University who was not involved in the study. “Being able to detect a change in the time delays between the echoes over the course of the outburst means we can start to learn about what is happening around the black hole.”

    2
    This illustration shows X-rays from the black hole’s corona (blue) echoing off its accretion disk (orange). Timing these echoes helped scientists determine that the corona was shrinking over time. Photo: NASA’s Goddard Space Flight Center

    Zeroing in on the corona is especially helpful because scientists think this region is likely the base from which powerful beams of particles and light, called relativistic jets, are launched. These jets travel close to light-speed and can be spotted coming from black holes across the universe. “The big fun of this paper, from my point of view, is that we really can ‘see’ the corona shrinking during the evolution of the outburst,” says Stephen Eikenberry of the University of Florida, a co-author on the new paper. “I don’t know of any real theoretical prediction for this ‘shrinkage’ nor of any prior observation of it, so this result will already require overhauling of the theories we have for jet formation.”

    The black hole in this study holds about 10 times the mass of the sun. The new observations should help astronomers understand not just star-size black holes like this one but also the gargantuan “supermassive” black holes that are located at the centers of galaxies and contain millions of times more mass. “These stellar-mass systems are a convenient analogue for supermassive black holes,” Kara says. “They have similar components, but we see outbursts over several weeks and months whereas for supermassive black holes it’s years.” The new findings support one theory for how supermassive black hole coronas are structured — called the “lamppost model” — which posits coronas are lightbulb-shaped blobs above and below the black hole, as opposed to diffuse clouds. “These new observations are exactly in line with the lamppost model,” Wilkins says. “Indeed, we observed very similar behavior during flares from supermassive black holes, seeing a change in the size of the corona.”

    Astronomers hope NICER, which launched in June 2017, and other new observatories will observe many more outbursts in the future and help fill in the missing details of erupting black holes. “It’s a really exciting time to be doing this,” says Joey Neilsen, a physicist at Villanova University and a co-author of the new paper. “We’re getting to a point where the observations are actually ahead of the theory. New missions are allowing us to see things that we hadn’t necessarily thought of before.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
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