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  • richardmitnick 2:05 pm on December 15, 2018 Permalink | Reply
    Tags: , , , , NASA/ESA Hera, NELIOTA-NEO Lunar Impacts and Optical TrAnsients, , Universe Today   

    From Science Alert: “Every Few Hours a Flash of Light Comes From The Moon. Another Impact” 

    ScienceAlert

    From Science Alert

    15 DEC 2018
    MATT WILLIAMS, THE UNIVERSE TODAY

    Ever since the Apollo missions explored the lunar surface, scientists have known that the Moon’s craters are the result of a long history of meteor and asteroid impacts. But it has only been in the past few decades that we have come to understand how regular these are.

    In fact, every few hours, an impact on the lunar surface is indicated by a bright flash. These impact flashes are designed as a “transient lunar phenomena” because they are fleeting.

    Basically, this means that the flashes (while common) last for only a fraction of a second, making them very difficult to detect. For this reason, the European Space Agency (ESA) created the NEO Lunar Impacts and Optical TrAnsients (NELIOTA) project in 2015 to monitor the moon for signs of impact flashes.

    By studying them, the project hopes to learn more about the size and distribution of near-Earth objects to determine if they pose a risk to Earth.

    To be fair, this phenomena is not new to astronomers, as flashes have been reportedly seen lighting up dark sections of the Moon for at least a thousand years.

    It has only been recently, however, that scientists have had telescopes and cameras sophisticated enough to observe these events and characterize them (i.e. size, speed and frequency).

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    (NASA/Jennifer Harbaugh)

    Determining how often such events take place, and what they can teach us about our Near-Earth environment is the reason the ESA created NELIOTA.

    In February of 2017, the project began a 22 month-long campaign to observe the Moon using the 1.2 m telescope at the Kryoneri Observatory located in Greece. This telescope is the largest instrument on Earth ever dedicated to monitoring the Moon.

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    Kryoneri Observatory, Greece

    In addition, the NELIOTA system is the first to use a 1.2 m-telescope for monitoring the Moon. Traditionally, lunar monitoring programs have relied on telescopes with primary mirrors measuring 0.5 m in diameter or smaller.

    The larger mirror of the Kryoneri telescope allows the NELIOTA scientists to detect flashes two magnitudes fainter than other lunar monitoring programs.

    But even with the right instruments, detecting these flashes is no easy task. In addition to lasting for only a fraction of a second, it is also impossible to spot them on the bright side of the Moon since the sunlight reflected from the surface is much brighter.

    For this reason, these events can only be seen on the Moon’s “dark side” – i.e. between a New Moon and First Quarter and between a Last Quarter and New Moon.

    The Moon must also be above the horizon at the time and observations must be conducted using a fast-frame camera. Because of these necessary conditions, the NELIOTA project has only been able to obtain 90 hours of observation time over a 22-month period, during which time 55 lunar impact events were observed.

    From this data, scientists were able to extrapolate that an average of about 8 flashes occur every hour on the surface of the Moon.

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    (ESA/AFP)

    Another feature that sets the NELIOTA project apart is its two fast-frame cameras that enable lunar monitoring in the visible and near-infrared bands of the spectrum.

    This allowed the project scientists to conduct the first study ever where the temperatures of lunar impacts were calculated. Of the first ten they detected, they obtained temperature estimates ranging from about 1,300 to 2,800 °C ( 2372 to 5072 °F).

    With the extension of this observing campaign to 2021, the NELIOTA scientists hope to obtain further data that will improve impact statistics.

    In turn, this information will go a long way towards addressing the threat of Near-Earth Objects – which consist of asteroids and comets that periodically pass close to Earth (and on rare occasions, impact on the surface).

    In the past, the ESA has monitored these objects through its Space Situational Awareness (SSA) program, of which the NELTIOA project is part.

    Today, the SSA is building infrastructure in space and on the ground (such as the deployment of Flyeye telescopes across the globe) to improve our monitoring and understanding of potentially hazardous NEOs.

    ESA Flyeye telescope

    In the future, the ESA plans to transition from monitoring NEOs to developing mitigation and active planetary defense strategies.

    This includes the proposed NASA/ESA Hera mission – formerly known as the Asteroid Impact & Deflection Assessment (AIDA) – which is scheduled to launch by 2023.

    NASA ESA Hera

    In the coming decades, other measures (ranging from directed energy and ballistic missiles to solar sails) are also likely to be investigated.

    But as always, the key to protecting Earth from future impacts is the existence of effective detection and monitoring strategies. In this respect, projects like NELIOTA will prove to be invaluable.

    See the full article here .


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  • richardmitnick 7:06 am on February 28, 2018 Permalink | Reply
    Tags: , , , , , , Universe Today   

    From Universe Today: “Amazing High Resolution Image of the Core of the Milky Way, a Region with Surprisingly Low Star Formation Compared to Other Galaxies” 

    universe-today

    Universe Today

    27 Feb , 2018
    Matt Williams

    1
    The centre of the Milky Way Galaxy seen through NASA’s Spitzer Space Telescope. http://www.spitzer.caltech.edu/images/1540-ssc2006-02a-A-Cauldron-of-Stars-at-the-Galaxy-s-Center

    NASA/Spitzer Infrared Telescope

    Compared to some other galaxies in our Universe, the Milky Way is a rather subtle character. In fact, there are galaxies that are a thousands times as luminous as the Milky Way, owing to the presence of warm gas in the galaxy’s Central Molecular Zone (CMZ). This gas is heated by massive bursts of star formation that surround the Supermassive Black Hole (SMBH) at the nucleus of the galaxy.

    The core of the Milky Way also has a SMBH (Sagittarius A*) and all the gas it needs to form new stars.

    SgrA* NASA/Chandra

    But for some reason, star formation in our galaxy’s CMZ is less than the average. To address this ongoing mystery, an international team of astronomers conducted a large and comprehensive study of the CMZ to search for answers as to why this might be.

    The study, titled Star formation in a high-pressure environment: an SMA view of the Galactic Centre dust ridge recently appeared in the Monthly Notices of the Royal Astronomical Society. The study was led by Daniel Walker of the Joint ALMA Observatory and the National Astronomical Observatory of Japan, and included members from multiple observatories, universities and research institutes.

    See the full article here .

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  • richardmitnick 9:25 am on February 4, 2018 Permalink | Reply
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    From Universe Today: “For the First Time, Planets Have Been Discovered in ANOTHER Galaxy!” 

    universe-today

    Universe Today

    3 Feb , 2018
    Matt Williams

    1
    Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle

    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    The first confirmed discovery of a planet beyond our Solar System (aka. an Extrasolar Planet) was a groundbreaking event. And while the initial discoveries were made using only ground-based observatories, and were therefore few and far between, the study of exoplanets has grown considerably with the deployment of space-based telescopes like the Kepler space telescope.

    As of February 1st, 2018, 3,728 planets have been confirmed in 2,794 systems, with 622 systems having more than one planet. But now, thanks to a new study by a team of astrophysicists from the University of Oklahoma, the first planets beyond our galaxy have been discovered! Using a technique predicting by Einstein’s Theory of General Relativity, this team found evidence of planets in a galaxy roughly 3.8 billion light years away.

    The study which details their discovery, titled Probing Planets in Extragalactic Galaxies Using Quasar Microlensing, recently appeared in The Astrophysical Journal Letters. The study was conducted by Xinyu Dai and Eduardo Guerras, a postdoctoral researcher and professor from the Homer L. Dodge Department of Physics and Astronomy at the University of Oklahoma, respectively.

    See the full article here .

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  • richardmitnick 11:33 am on January 25, 2018 Permalink | Reply
    Tags: , , , , , Π1 Gruis, This is the Surface of a Giant Star 350 Times Larger Than the Sun, Universe Today   

    From Universe Today: “This is the Surface of a Giant Star, 350 Times Larger Than the Sun” 

    universe-today

    Universe Today

    24 Jan , 2018
    Matt Williams

    1
    This artist’s impression shows the red supergiant star. Using ESO’s Very Large Telescope Interferometer, an international team of astronomers have constructed the most detailed image ever of this, or any star other than the Sun. Credit: ESO/M. Kornmesser.

    2009 ESO VLT Interferometer image, Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    When it comes to looking beyond our Solar System, astronomers are often forced to theorize about what they don’t know based on what they do. In short, they have to rely on what we have learned studying the Sun and the planets from our own Solar System in order to make educated guesses about how other star systems and their respective bodies formed and evolved.

    For example, astronomers have learned much from our Sun about how convection plays a major role in the life of stars. Until now, they have not been able to conduct detailed studies of the surfaces of other stars because of their distances and obscuring factors. However, in a historic first, an international team of scientists recently created the first detailed images of the surface of a red giant star located roughly 530 light-years away.

    The study recently appeared in the scientific journal Nature under the title Large Granulation cells on the surface of the giant star Π¹ Gruis. The study was led by Claudia Paladini of the Université libre de Bruxelles and included members from the European Southern Observatory, the Université de Nice Sophia-Antipolis, Georgia State University, the Université Grenoble Alpes, Uppsala University, the University of Vienna, and the University of Exeter.

    For the sake of their study, the team used the Precision Integrated-Optics Near-infrared Imaging ExpeRiment (PIONIER) instrument on the ESO’s Very Large Telescope Interferometer (VLTI) to observe the star known as Π¹ Gruis.

    ESO VLTI PIONIER instrument [First light October 2010]

    Located 530 light-years from Earth in the constellation of Grus (The Crane), Π1 Gruis is a cool red giant. While it is the same mass as our Sun, it is 350 times larger and several thousand times as bright.

    See the full article here .

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  • richardmitnick 8:57 am on January 20, 2018 Permalink | Reply
    Tags: A Black Hole is Pushing the Stars Around in this Globular Cluster, , , , , Universe Today   

    From Universe Today: “A Black Hole is Pushing the Stars Around in this Globular Cluster” 

    universe-today

    Universe Today

    19 Jan , 2018
    Matt Williams

    1
    Artist’s impression of the star cluster NGC 3201 orbiting an black hole with about four times the mass of the Sun. Credit: ESO/L. Calçada

    Astronomers have been fascinated with globular clusters ever since they were first observed in 17th century. These spherical collections of stars are among the oldest known stellar systems in the Universe, dating back to the early Universe when galaxies were just beginning to grow and evolve. Such clusters orbit the centers of most galaxies, with over 150 known to belong to the Milky Way alone.

    One of these clusters is known as NGC 3201, a cluster located about 16,300 light years away in the southern constellation of Vela. Using the ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile, a team of astronomers recently studied this cluster and noticed something very interesting. According to the study they released, this cluster appears to have a black hole embedded in it.

    ESO VLT Platform at Cerro Paranal elevation 2,635 m (8,645 ft)

    The study appeared in the Monthly Notices of the Royal Astronomical Society under the title A detached stellar-mass black hole candidate in the globular cluster NGC 3201. The study was led by Benjamin Giesers of the Georg-August-University of Göttingen and included members from Liverpool John Moores University, Queen Mary University of London, the Leiden Observatory, the Institute of Astrophysics and Space Sciences, ETH Zurich, and the Leibniz Institute for Astrophysics Potsdam (AIP).

    See the full article here .

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  • richardmitnick 8:43 am on January 20, 2018 Permalink | Reply
    Tags: , , , , Researchers Develop a New Low Cost/Low Weight Method of Searching for Life on Mars, Universe Today   

    From Universe Today: “Researchers Develop a New Low Cost/Low Weight Method of Searching for Life on Mars” 

    universe-today

    Universe Today

    19 Jan , 2018
    Evan Gough

    1
    Study co-author I. Altshuler sampling permafrost terrain near the McGill Arctic research station, Canadian high Arctic. Image: Dr. Jacqueline Goordial

    Researchers at Canada’s McGill University have shown for the first time how existing technology could be used to directly detect life on Mars and other planets. The team conducted tests in Canada’s high arctic, which is a close analog to Martian conditions. They showed how low-weight, low-cost, low-energy instruments could detect and sequence alien micro-organisms. They presented their results in the journal Frontiers in Microbiology.

    Getting samples back to a lab to test is a time consuming process here on Earth. Add in the difficulty of returning samples from Mars, or from Ganymede or other worlds in our Solar System, and the search for life looks like a daunting task. But the search for life elsewhere in our Solar System is a major goal of today’s space science. The team at McGill wanted to show that, conceptually at least, samples could be tested, sequenced, and grown in-situ at Mars or other locations. And it looks like they’ve succeeded.

    See the full article here .

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  • richardmitnick 10:48 am on January 10, 2018 Permalink | Reply
    Tags: , , , , The Night Sky Magic of the Atacama, Universe Today   

    From Universe Today: “The Night Sky Magic of the Atacama” 

    universe-today

    Universe Today

    10 Jan , 2018
    Paul M. Sutter

    1
    The ESO’s Paranal Observatory sits proudly above the Atacama desert. No image credit.

    There’s nothing an astronomer – whether professional or amateur – loves more than a clear dark night sky away from the city lights. Outside the glare and glow and cloud cover that most of us experience every day, the night sky comes alive with a life of its own.

    Thousands upon countless thousands of glittering jewels – each individual star a pinprick of light set against the velvet-smooth blackness of the deeper void. The arching band of the Milky Way, itself host to billions more stars so far away that we can only see their combined light from our vantage point. The familiar constellations, proudly showing their true character, drawing the eye and the mind to the ancient tales spun about them.

    There are few places left in the world to see the sky as our ancestors did; to gaze in wonder at the celestial dome and feel the weight of billions of years of cosmic history hanging above us. Thankfully the International Dark Sky Association is working to preserve what’s left of the true night sky, and they’ve rightfully marked northern Chile to preserve for posterity.

    There, the Elqui Valley and the Atacama Desert host night skies impossible to see elsewhere. Away from cities, tucked between the Pacific coast and the high peaks of the Andes, the dry desert air and high elevations make for some of the best observing grounds you can find on Earth.

    See the full article here .

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  • richardmitnick 12:42 pm on December 23, 2017 Permalink | Reply
    Tags: , , , , Universe Today, What is the Radial Velocity Method?   

    From Universe Today: “What is the Radial Velocity Method?” 

    universe-today

    Universe Today

    22 Dec , 2017
    Matt Williams

    1
    Artist’s impression of Proxima b, which was discovered using the Radial Velocity method. Credit: ESO/M. Kornmesser

    The hunt for extra-solar planets sure has heated up in the past decade or so! Thanks to improvements made in instrumentation and methodology, the number of exoplanets discovered (as of December 1st, 2017) has reached 3,710 planets in 2,780 star systems, with 621 system boasting multiple planets. Unfortunately, due to the limits astronomers are forced to contend with, the vast majority have been discovered using indirect methods.

    When it comes to these indirect methods, one of the most popular and effective is the Radial Velocity Method – also known as Doppler Spectroscopy. This method relies on observing the spectra stars for signs of “wobble”, where the star is found to be moving towards and away from Earth. This movement is caused by the presence of planets, which exert a gravitational influence on their respective sun.

    Description:

    Essentially, the Radial Velocity Method consists not of looking for signs of planets themselves, but in observing a star for signs of movement. This is deduced by using a spectometer to measure the way in which the star’s spectral lines are displaced due to the Doppler Effect – i.e. how light from the star is shifted towards the red or blue end of the spectrum (redshift/blueshift).

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    Diagram detailing the Radial Velocity (aka. Doppler Shift) method. Credit: Las Cumbres Observatory.

    These shifts are indications that the star is moving away from (redshift) or towards (blueshift) Earth. Based on the star’s velocity, astronomers can determine the presence of a planet or system of planets. The speed at which a star moves around its center of mass, which is much smaller than that of a planet, is nevertheless measurable using today’s spectrometers.

    Until 2012, this method was the most effective means of detecting exoplanets, but has since come to be replaced by the Transit Photometry.

    Planet transit. NASA/Ames

    Nevertheless, it remains a highly effective method and is often relied upon in conjunction with the Transit Method to confirm the existence of exoplanets and place constraints on their size and mass.

    See the full article here .

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  • richardmitnick 12:12 pm on December 21, 2017 Permalink | Reply
    Tags: , , , , Exoplanet GJ 436b, Planet Orbiting at Right Angles. Mayhem., Red Dwarf Star, Universe Today   

    From Universe Today: “Red Dwarf Star, Planet Orbiting at Right Angles. Mayhem.” 

    universe-today

    Universe Today

    20 Dec , 2017
    Matt Williams

    1
    Artist’s impression of vessels floating near GJ436 its exoplanet, which orbits its star from pole to pole. Credit: University of Geneva/Denis Bajram

    When we think of other planetary systems, we tend to think that they will operate by the same basic rules as our own. In the Solar System, the planets orbit close to the equatorial plane of the Sun – meaning around its equator. The Sun’s rotational axis, the direction of its poles based to its rotation, is also the same as most of the planets’ (the exception being Uranus, which rotates on its side).

    But if the study of extra-solar planets has taught us anything, it is that the Universe is full of possibilities. Consider the star known as GJ436, a red dwarf located about 33 light-years from Earth. For years, astronomers have known that this star has a planet that behaves very much like a comet. But according to a recent study led by astronomers from the University of Geneva (UNIGE), this planet also has a very peculiar orbit.

    The study, titled Orbital Misalignment of the Neptune-mass Exoplanet GJ 436b With the Spin of its Cool Star, recently appeared in the scientific journal Nature. The study was led by Vincent Bourrier of the Geneva University Observatory, and included members from the University of Grenoble Alpes, Tennessee State University, and the Center for Space and Habitability at the University of Bern.

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    Artist’s concept of the Neptune-sized planet Gliese 436b, surrounded by an envelop of hydrogen gas. Credit: NASA/ESA/STScI/G. Bacon

    GJ436 has already been the source of much scientific interest, thanks in part to the discovery that its only confirmed exoplanet has a gaseous envelop similar a comet. This exoplanet, known as GJ436b, was first observed in 2004 using radial velocity measurements taken by the Keck Observatory.

    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    In 2007, GJ436b became the first Neptune-sized planet known to be orbiting very closely to its star (aka. a “Hot Neptune”).

    See the full article here .

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  • richardmitnick 2:10 pm on December 15, 2017 Permalink | Reply
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    From Universe Today: “Gaia Looks Beyond our Galaxy to Other Islands of Stars” 

    universe-today

    Universe Today

    15 Dec, 2017
    Matt Williams

    1
    Color view of Messier 31 (The Andromeda Galaxy), with Messier 32 (a satellite galaxy) shown to the lower left. Credit and copyright: Terry Hancock.

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    Gaia’s view of the Andromeda galaxy. Credit: ESA/Gaia/DPAC

    The European Space Agency’s (ESA) Gaia mission is an ambitious project.

    ESA/GAIA satellite

    Having launched in December of 2013, the purpose of this space observatory has been to measure the position and distances of 1 billion objects – including stars, extra-solar planets, comets, asteroids and even quasars. From this, astronomers hope to create the most detailed 3D space catalog of the cosmos ever made.

    Back in 2016, the first batch of Gaia data (based on its first 14 months in space) was released. Since then, scientists have been pouring over the raw data to obtain clearer images of the neighboring stars and galaxies that were studied by the mission. The latest images to be released, based on Gaia data, included revealing pictures of the Large Magellanic Cloud (LMC), the Andromeda galaxy, and the Triangulum galaxy.

    The first catalog of Gaia data consisted of information on 1.142 billion stars, including their precise position in the night sky and their respective brightness. Most of these stars are located in the Milky Way, but a good fraction were from galaxies beyond ours, which included about ten million belonging to the LMC. This satellite galaxy, located about 166 000 light-years away, has about 1/100th the mass of the Milky Way.

    See the full article here .

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