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  • richardmitnick 8:39 am on September 24, 2019 Permalink | Reply
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    From BBC via Sanford Underground Research Facility: “LUX-ZEPLIN: the new experiment hoping to detect dark matter” 

    SURF logo
    Sanford Underground levels

    Sanford Underground Research Facility


    Homestake Mining Company

    BBC
    From BBC

    BBC’s Sky at Night’s Iain Todd spoke to Jaret Heise about an experiment aiming to make the first direct detection of dark matter.

    1
    Jaret Heise, science director at Sanford Underground Research Facility, stands in front of the Yates Headframe. Photo by Nick Hubbard

    A mile below Earth’s surface at the Sanford Underground Research Facility (Sanford Lab) in South Dakota, US, something exciting is happening. There, scientists are carrying out an experiment named LUX-ZEPLIN (LZ), with the aim of making the first ever detection of the allusive substance known as dark matter.

    Dark matter can’t be directly observed: it currently can’t even be detected. Yet astronomers have inferred its existence by the way it interacts gravitationally with observable matter in the Universe.

    In fact, that observable matter pales in comparison to the distribution of dark matter in the Universe, so finding out exactly what dark matter is, and how it can be detected, is one of the big questions that scientists are hoping to solve over the coming years.

    We spoke to Jaret Heise, science director at the Sanford Lab, to find out exactly how the LZ experiment works and, if it is successful, what it might mean for our understanding of the Universe.

    First off, tell us about the Sanford facility and the sort of work that is done there.

    We’re a research facility dedicated to underground science; actually the deepest underground lab in the United States.

    Our mission is to advance compelling and transformational science, and as the science director I get to interact with groups that are interested in trying to answer big questions.

    Right now our facility currently supports 30 different experiments representing 80 institutions and 100s of researchers, so I would say I have the best job in the whole place!

    What is the LUX-ZEPLIN experiment?

    The LZ dark matter detector is built on the foundations of two previous experiments: the LUX experiment that operated at our facility and which was turned off in 2016 to make way for the upgrade, LZ.

    U Washington LUX Dark matter Experiment at SURF, Lead, SD, USA

    ZEPLIN was another dark matter experiment that operated in the UK at the Boulby Underground Laboratory for many years and through many generations.

    So combining the intellectual horsepower of those two operations has resulted in the LZ experiment that’s hosted at our facility just about a mile underground in the Davis Campus, which was created in 2012 when the LUX experiment was moved in to begin its data run.

    The depth of the underground lab, in so far as affecting the physics of the experiment, is really to screen unwanted particles that would contribute background noise.

    Those muons are generated by cosmic ray particles interacting in the upper atmosphere, producing a shower of muons.

    The muons are very energetic and would constitute a background noise if you were to do some of these really sensitive measurements looking for very rare processes on the surface.

    Moving a mile underground in our case shields those background particles, reducing them by a factor of about ten million.

    So rather than two or three on the surface, if you go underground on the Davis Campus, you’re looking at one of these cosmic ray muons per month, and if you’re a rare physics experiment trying to be the first to detect dark matter directly, you want to give yourself every advantage.

    There’s no guarantee that nature will be so kind, but you couldn’t do these experiments on the surface in the way that they’re proposed.

    How does the detector work?

    The LUX-ZEPLIN is basically a big bucket full of xenon. The LUX detector before it was also a big bucket of xenon; this is a larger bucket of xenon!

    LUX started with a third of a tonne – just over 350kg – and the LZ will have 10 tonnes; so a scaling-up of about 30 times.

    The way the detector operates is that xenon both scintillates and becomes ionised when particles hit it, so you have an initial burst of light from the scintillation, the deposition of energy.

    Those initial particles can be ones that we know about already; they could be beta particles, they could be neutrons. These are particles that are very familiar to us.

    They could also be dark matter particles that interact very weakly, possibly just gravitationally, but maybe a little higher up in the interaction spectrum if they also interact weakly.

    4
    An array of photomultiplier tubes designed to detect signals occurring within LUX-ZEPLIN’s liquid xenon tank.
    Photo by Matthew Kapust

    A lot of experiments these days are focussing on the weakly interacting massive particle, or WIMPs.

    In the case of LZ, with 10 tonnes of xenon, the scientists are looking for bursts of light.

    They’ll have light sensors, photomultiplier tubes on the top of the region and on the bottom of the region sandwiching the xenon, looking for signals that a particle has interacted with a xenon particle.

    Based on the amount of light that’s given off in the initial scintillation burst, compared to a secondary ionisation measurement, they can determine what type of particle it is.

    They can weed out the ones we know about already and look for the ones that we have never seen before.

    Is it a process of elimination?

    In a way, yes it is. It’s a process of understanding the detector extremely well.

    In the case of experiments at our facility, moving a mile underground and away from that cosmic ray background is important.

    Also, shielding from the natural radioactivity in the laboratory is important. Everything has radioactivity: the concrete, the paint on the walls, the people, the bananas that people bring for lunch: everything has a small amount of radioactivity.

    The LZ experiment is planning to have their titanium vessel with 10 tonnes of xenon immersed inside a large water shielding tank.

    LZ has innovated one additional detector as compared to the original LUX run. Here they’re going to use an additional liquid scintillator, and that will help them detect neutrons that are also generated naturally in the laboratory.

    Neutrons are particularly dangerous background because they have no electrical charge and they’re relatively massive. So they can mimic the signal of a dark matter particle fairly well.

    Understanding the response of the detector to neutrons is very important, and understanding the flux of neutrons that is present is also extremely important.

    So it’s a process of elimination, but it’s also about understanding things that you can lay your hands on as best as you can: understanding the background of all the parts and pieces that went into constructing the detector.

    We have low background counters at our facility where you would put in the nuts and bolts and light sensors and titanium samples and figure out in some cases what the best manufacturer is, and which one will give you the lowest radioactive components.

    In some cases where you don’t have a choice and have already made a selection, you still want to understand how much intrinsic radioactivity is in that part or piece so that you can determine how much background you’ll see within your detector when you turn it on, so that you can then look for signals outside of that range.

    Why do you think it’s so important that we do detect and understand more about dark matter?

    Dark matter is a very important component of our Universe, as we have discovered.

    There’s five times more dark matter in the Universe than the normal matter that we know and love: tables, chairs, planets, stars, galaxies. All of the normal matter makes up four per cent of the Universe.

    We’re looking for something that is five times more plentiful.

    It has almost certainly affected the formation of our Galaxy, and it plays a huge role in the evolution of our Universe.

    Not only that, but we can train the next round of scientists on how to build the next round of detectors, so we’re training qualified personnel to work on these experiments.

    It’s a great way to engage the public as well. Tell them about these cool particles no-one has ever seen before, and you can really get people excited about science.

    So it runs the gamut from basic research to understanding our Universe, and who knows what we will be able to do with the information once we find dark matter. Are there different types of dark matter? Who knows.

    Once we discover dark matter it’s probably not going to make our computers run faster or improve your TV resolution or things that people are looking at from a practical point of view, but knowing what the Universe is made of gives us that much more leverage to understand what we can do in the future.

    Is dark matter everywhere? If someone is reading this interview, is it in the room where they’re sitting, for example?

    We believe it is. If you had a 2 litre soda pop bottle, there would probably be something like one dark matter particle in that volume.

    We believe it is ubiquitous through the Galaxy. Since it interacts gravitationally, there might be more of it in the centre of the Galaxy, and there are groups – other than LZ, which is looking for direct signatures – that are looking for indirect signatures.

    Maybe the dark matter particles will collide, or maybe they can decay. Some satellite-based instruments are looking at the centre of the Galaxy because they expect there to be a higher concentration of dark matter in that area. But yes, we believe it’s all around us.

    Do you think there could ever be a telescope built that would be able to directly observe dark matter?

    I think you could have a visual representation, but I don’t know that we would ever see dark matter directly, the same way that we can’t directly see some of the lightest particles that we know of today.

    Neutrinos would be a good example. We see them indirectly because of how they interact with other matter, whether they hit other charged particles and produce light that we can see with instruments.

    Often we see these rare weakly-interacting signals only indirectly, but that doesn’t mean that we can’t represent them in some way and there are graphics showing what the dark matter concentration looks like in our Galaxy based on certain models.

    So we have that ability, but actually seeing a dark matter particle directly with our own eyes? I’m sceptical about that!

    5
    A Hubble Space Telescope Chandra X-ray Observatory and Canada-France-Hawaii Telescope composite showing the distribution of dark matter and hot gas in merging galaxy cluster Abell 520. False colour has been added. Orange represents starlight and green regions show hot gas, whereas blue-coloured areas show the location of most of the mass in the cluster, which is dominated by dark matter. NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University).

    NASA/ESA Hubble Telescope

    NASA/Chandra X-ray Telescope


    CFHT Telescope, Maunakea, Hawaii, USA, at Maunakea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    If money were no object, would it be more scientifically advantageous to launch the LZ experiment into space?

    The search for dark matter is multi-faceted, combining the efforts of underground scientists like we have here at Sanford Lab, accelerator scientists as well as satellites.

    We’re all complementing each other in that search. The accelerator scientists are trying to reproduce a candidate particle that might be a weakly-interacting massive particle.

    The satellites are looking for indirect signals of WIMP annihilation or decay of dark matter particles.

    So we already are in space and we already are building some of the largest machines humans have ever made, coming at the search for dark matter in all the ways we can think of.

    If money was no object for underground science, we would probably build a larger version!

    But having said that, we’re already running in with the current set of experiments. The sensitivity of these instruments is so exquisite, that the search for dark matter is now going to be clouded to a certain degree by neutrinos coming from our Sun.

    It’s a really interesting story at our facility because some of the first measurements of neutrinos coming from our Sun were performed by Ray Davis here in Lead, South Dakota, starting back in the 1960s, when he convinced the Homestake Mining Company to dig a big pit and help him install a detector for that purpose.

    He had 100,000 gallons’ worth of dry-cleaning fluid to search for interactions of neutrinos over decades. Now those same neutrinos coming from the Sun are the background for searches for other particles.

    That doesn’t mean that we can’t continue to look for dark matter with a bigger instrument, but going deeper won’t screen out the neutrinos. However, that doesn’t mean that the next version, a scale above the LZ experiment, wouldn’t be profitable.

    What’s next for the project and do you have any idea when to expect the first results?

    The collaboration is assembling the instrument. We have clean rooms in our surface facility and the inner components of the detector have been put together, inserted into the titanium inner vessel.

    We expect to be able to transport that instrument underground around October 2019 and it’ll be installed in that large water shielding tank.

    There’ll be a process for checking it out and making sure everything is working.

    They hope to start taking physics data some time in 2020.

    First results; I don’t want to speak for the collaboration but we hope to have the first result within a year of turning the instrument on, so maybe some time in 2021 we would look forward to the latest and greatest dark matter result, whether that’s a confirmation of a signal or pushing the boundaries of the sensitivity of instruments looking for dark matter.

    LBNL LZ Dark Matter project at SURF, Lead, SD, USA

    The recently assembled LUX-ZEPLIN xenon detector in the Surface Assembly Lab cleanroom at SURF

    See the full article here .


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    About us.
    The Sanford Underground Research Facility in Lead, South Dakota, advances our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. Researchers at the Sanford Lab explore some of the most challenging questions facing 21st century physics, such as the origin of matter, the nature of dark matter and the properties of neutrinos. The facility also hosts experiments in other disciplines—including geology, biology and engineering.

    The Sanford Lab is located at the former Homestake gold mine, which was a physics landmark long before being converted into a dedicated science facility. Nuclear chemist Ray Davis earned a share of the Nobel Prize for Physics in 2002 for a solar neutrino experiment he installed 4,850 feet underground in the mine.

    Homestake closed in 2003, but the company donated the property to South Dakota in 2006 for use as an underground laboratory. That same year, philanthropist T. Denny Sanford donated $70 million to the project. The South Dakota Legislature also created the South Dakota Science and Technology Authority to operate the lab. The state Legislature has committed more than $40 million in state funds to the project, and South Dakota also obtained a $10 million Community Development Block Grant to help rehabilitate the facility.

    In 2007, after the National Science Foundation named Homestake as the preferred site for a proposed national Deep Underground Science and Engineering Laboratory (DUSEL), the South Dakota Science and Technology Authority (SDSTA) began reopening the former gold mine.

    In December 2010, the National Science Board decided not to fund further design of DUSEL. However, in 2011 the Department of Energy, through the Lawrence Berkeley National Laboratory, agreed to support ongoing science operations at Sanford Lab, while investigating how to use the underground research facility for other longer-term experiments. The SDSTA, which owns Sanford Lab, continues to operate the facility under that agreement with Berkeley Lab.

    The first two major physics experiments at the Sanford Lab are 4,850 feet underground in an area called the Davis Campus, named for the late Ray Davis. The Large Underground Xenon (LUX) experiment is housed in the same cavern excavated for Ray Davis’s experiment in the 1960s.

    LBNL LZ project at SURF, Lead, SD, USA, will replace LUX at SURF

    In October 2013, after an initial run of 80 days, LUX was determined to be the most sensitive detector yet to search for dark matter—a mysterious, yet-to-be-detected substance thought to be the most prevalent matter in the universe. The Majorana Demonstrator experiment, also on the 4850 Level, is searching for a rare phenomenon called “neutrinoless double-beta decay” that could reveal whether subatomic particles called neutrinos can be their own antiparticle. Detection of neutrinoless double-beta decay could help determine why matter prevailed over antimatter. The Majorana Demonstrator experiment is adjacent to the original Davis cavern.

    LUX’s mission was to scour the universe for WIMPs, vetoing all other signatures. It would continue to do just that for another three years before it was decommissioned in 2016.

    In the midst of the excitement over first results, the LUX collaboration was already casting its gaze forward. Planning for a next-generation dark matter experiment at Sanford Lab was already under way. Named LUX-ZEPLIN (LZ), the next-generation experiment would increase the sensitivity of LUX 100 times.

    SLAC physicist Tom Shutt, a previous co-spokesperson for LUX, said one goal of the experiment was to figure out how to build an even larger detector.
    “LZ will be a thousand times more sensitive than the LUX detector,” Shutt said. “It will just begin to see an irreducible background of neutrinos that may ultimately set the limit to our ability to measure dark matter.”
    We celebrate five years of LUX, and look into the steps being taken toward the much larger and far more sensitive experiment.

    Another major experiment, the Long Baseline Neutrino Experiment (LBNE)—a collaboration with Fermi National Accelerator Laboratory (Fermilab) and Sanford Lab, is in the preliminary design stages. The project got a major boost last year when Congress approved and the president signed an Omnibus Appropriations bill that will fund LBNE operations through FY 2014. Called the “next frontier of particle physics,” LBNE will follow neutrinos as they travel 800 miles through the earth, from FermiLab in Batavia, Ill., to Sanford Lab.

    FNAL LBNE/DUNE from FNAL to SURF, Lead, South Dakota, USA


    LBNE

    U Washington Majorana Demonstrator Experiment at SURF

    The MAJORANA DEMONSTRATOR will contain 40 kg of germanium; up to 30 kg will be enriched to 86% in 76Ge. The DEMONSTRATOR will be deployed deep underground in an ultra-low-background shielded environment in the Sanford Underground Research Facility (SURF) in Lead, SD. The goal of the DEMONSTRATOR is to determine whether a future 1-tonne experiment can achieve a background goal of one count per tonne-year in a 4-keV region of interest around the 76Ge 0νββ Q-value at 2039 keV. MAJORANA plans to collaborate with GERDA for a future tonne-scale 76Ge 0νββ search.

    CASPAR at SURF


    CASPAR is a low-energy particle accelerator that allows researchers to study processes that take place inside collapsing stars.

    The scientists are using space in the Sanford Underground Research Facility (SURF) in Lead, South Dakota, to work on a project called the Compact Accelerator System for Performing Astrophysical Research (CASPAR). CASPAR uses a low-energy particle accelerator that will allow researchers to mimic nuclear fusion reactions in stars. If successful, their findings could help complete our picture of how the elements in our universe are built. “Nuclear astrophysics is about what goes on inside the star, not outside of it,” said Dan Robertson, a Notre Dame assistant research professor of astrophysics working on CASPAR. “It is not observational, but experimental. The idea is to reproduce the stellar environment, to reproduce the reactions within a star.”

     
  • richardmitnick 9:04 am on August 30, 2019 Permalink | Reply
    Tags: "'Rosalind Franklin' Mars rover assembly completed", Airbus' facility in Stevenage, , , , , BBC, Called "Rosalind Franklin" after the British DNA pioneer the six-wheeled robot will search for life on Mars., China and the US are preparing their own rovers for launch in the same departure window as Rosalind Franklin., China's vehicle dubbed XH-1 is a slightly smaller concept., , Development work at component and instrument level has consumed more than a decade., , It is an eight-month cruise to Mars with the landing on an ancient equatorial plain targeted for 19 March 2021., Lift-off atop a Proton rocket is scheduled for July 2020., , , , The new rover follows the design template of the Curiosity robot which landed on Mars in 2012., The Rosalind Franklin rover carries a drill to collect samples from below the Martian surface., The UK made the rover a centrepiece of its space science policy.   

    From BBC: “‘Rosalind Franklin’ Mars rover assembly completed” 

    BBC
    From BBC

    27 August 2019
    Jonathan Amos

    Assembly of the rover Europe and Russia plan to send to the Red Planet next year is complete.

    10
    The rover is named after the British scientist who helped decipher the structure of DNA. MRC Laboratory of Molecular Biology.

    Engineers at Airbus in Stevenage, UK, displayed the finished vehicle on Tuesday ahead of its shipment to France for testing.

    Called “Rosalind Franklin” after the British DNA pioneer, the six-wheeled robot will search for life on Mars.

    It has a drill to burrow 2m below ground to try to detect the presence of microbes, either living or fossilised.

    The project is a joint endeavour of the European and Russian space agencies (ESA and Roscosmos), with input from the Canadians and the US.

    2
    The UK made the rover a centrepiece of its space science policy.

    4
    The Rosalind Franklin rover is nearing completion at Airbus’ facility in Stevenage. EMMA UNDERWOOD/Airbus

    3
    The Rosalind Franklin rover carries a drill to collect samples from below the Martian surface. ESA.

    5
    Kazachok lander: The rover needs a means to get it safely to the surface of Mars. TAS.

    6
    American rovers have established that Mars was certainly habitable – but was it inhabited? NASA/JPL-CALTECH/MSSS [Malin Space Science Systems].

    7
    Jezero Crater shows strong evidence from orbit of past water activity. NASA/JPL/JHUAPL/MSSS/BROWN UNIVERSITY

    8
    The new rover follows the design template of the Curiosity robot which landed on Mars in 2012. NASA.

    Although the rover’s build took just nine months, development work at component and instrument level has consumed more than a decade (the initial feasibility study was started in 2004).

    Lift-off atop a Proton rocket is scheduled for July 2020. It is an eight-month cruise to Mars, with the landing on an ancient equatorial plain targeted for 19 March, 2021, around 0600 local Mars time.

    China and the US are preparing their own rovers for launch in the same departure window as Rosalind Franklin.

    China’s vehicle, dubbed XH-1, is a slightly smaller concept. The Americans are assembling a near-copy of the one-tonne Curiosity robot that has been investigating the Red Planet for the past seven years. Their machine is codenamed currently simply Mars 2020.

    NASA Mars 2020 rover schematic

    NASA Mars 2020 Rover

    The roughly 300kg Rosalind Franklin rover is being bagged and boxed, ready to be sent to an Airbus facility in Toulouse this week. It’s in southwest France that a series of checks will ensure the robot can withstand the rigours of interplanetary travel and operation.

    There are actually three outstanding items yet to be integrated on the rover.

    These are the radioisotope heaters that will keep the vehicle warm in the bitter conditions on Mars. But they are a Russian expertise and will not be inserted until just prior to blast-off.

    In parallel with the work on the rover, engineers in Italy at the Thales Alenia Space (TAS) company are preparing the mechanisms required to get the rover safely to, and on to, Mars.

    In Turin on Wednesday, the German cruise spacecraft that will shepherd the robot to the Red Planet, and the Russian descent module, which will protect it as it enters Mars’ atmosphere, will have their first fit-check.

    Eventually, all elements of the mission will meet in Cannes, at another TAS factory, for end-to-end mating and balancing.

    “When the spacecraft is sent to Mars, it will be spinning. Like the wheels on your car, we have to check the balance to make sure everything spins smoothly,” explained Van Odedra, Airbus rover project manager.

    The entire system should be despatched to the Baikonur launch site in April to begin the process of preparing for the Proton lift-off.

    Rosalind Franklin was “superb scientific tool”, said David Parker, Esa’s director of human and robotic exploration.

    “We still have big challenges ahead but mission success is our number one priority.”

    9
    The rover will travel to Mars inside a capsule attached to a German cruise vehicle. ESA.

    What’s the critical next hurdle?

    Currently, there is concern over the readiness of the parachute system that will slow Rosalind Franklin’s descent through Mars’ atmosphere to the surface.

    Engineers have designed a two-chute system: a smaller supersonic envelope that opens first and a big subsonic membrane that opens once the entry speed has become manageable.

    Two tests earlier this year – on both chute types – led to tearing on deployment.

    Pietro Baglioni, ESA’s ExoMars manager, said the problem appeared to stem from the way the parachutes were packed and then extracted – not from the nature of the material used to fabricate them.

    ESA has called in NASA to help with finding a solution because the American agency saw something similar during the development of the parachute system used on the successful Spirit and Opportunity rovers in 2004.

    Further tests are planned for November and February.

    The November demonstration will see engineers travel to Oregon for the launch of a stratospheric balloon.

    This will drop a dummy mass from 30km in altitude; a mortar will fire the supersonic chute out of its container to simulate a Mars descent.

    Mr Baglioni said the November test had “to show that the implemented corrective measures are at least on the right track. Going for a redesign of the entire parachute system is out of the question for a 2020 launch.”

    A formal “go/no-go” decision on the mission is expected early next year.

    Why is Rosalind Franklin important for the UK?

    Tuesday’s send-off in front of the media was a big moment for the UK, which has made the Mars robot a central feature of its space science policy this past decade.

    Britain has invested in the order of €290m (£260m) in the wider Esa-Roscosmos programme, codenamed ExoMars, that also includes a satellite positioned in orbit around the Red Planet. This satellite will act as the relay to send the rover’s data home and, in the other direction, to feed Rosalind Franklin new commands.

    A further £14m (€16m) of UK public money was also set aside specifically for instrument contributions on both the rover and the satellite.

    UK scientists lead the PanCam (the panoramic camera system on the rover), for example, which will take the pictures that help the robot navigate Mars’ terrain and identify the rocks of greatest interest.

    With Rosalind Franklin now about to depart the country, there’s intense interest in a follow-up.

    Study work at Airbus-Stevenage is already considering the design of a rover that would pick up rock samples cached by Mars 2020 during its mission.

    The aim would be to bring these samples back to Earth for a deeper analysis than is possible on Mars with remote laboratory tools.

    The UK will tell its ESA partners when they gather in Spain in November for a major ministerial meeting that it will invest a substantial sum to secure the lead in building the “fetch rover”, as it has become known.

    See the full article here .

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  • richardmitnick 12:28 pm on March 19, 2019 Permalink | Reply
    Tags: , BBC,   

    From BBC: “US detects huge meteor explosion” 

    BBC
    From BBC

    18 March 2019
    Paul Rincon

    A huge fireball exploded in the Earth’s atmosphere in December, according to NASA.

    1
    Artwork: The fireball was the kind of event expected to happen only two to three times per century. Getty Images

    The blast was the second largest of its kind in 30 years, and the biggest since the fireball over Chelyabinsk in Russia six years ago.

    But it went largely unnoticed until now because it blew up over the Bering Sea, off Russia’s Kamchatka Peninsula.

    The space rock exploded with 10 times the energy released by the Hiroshima atomic bomb.

    Lindley Johnson, planetary defence officer at NASA, told BBC News a fireball this big is only expected about two or three times every 100 years.

    What do we know?

    At about noon local time on 18 December, the asteroid barrelled through the atmosphere at a speed of 32km/s (20 miles per second) , on a steep trajectory of seven degrees.

    Measuring several metres in size, the space rock exploded 25.6km above the Earth’s surface, with an impact energy of 173 kilotons.

    “That was 40% the energy release of Chelyabinsk, but it was over the Bering Sea so it didn’t have the same type of effect or show up in the news,” said Kelly Fast, near-Earth objects observations programme manager at Nasa.

    “That’s another thing we have in our defence, there’s plenty of water on the planet.”

    Dr Fast was discussing the event here at the 50th Lunar and Planetary Science Conference in The Woodlands, near Houston, Texas.

    Military satellites picked up the blast last year; NASA was notified of the event by the US Air Force.

    Dr Johnson said the fireball came in over an area not too far from routes used by commercial planes flying between North America and Asia. So researchers have been checking with airlines to see if there were any reported sightings of the event.

    2

    What’s the significance?

    In 2005, Congress tasked NASA with finding 90% of near-Earth asteroids of 140m (460ft) in size or larger by 2020. Space rocks of this size are so-called “problems without passports” because they are expected to affect whole regions if they collide with Earth. But scientists estimate it will take them another 30 years to fulfill this congressional directive.

    NASA NEOCAM

    Once an incoming object is identified, NASA has had some notable success at calculating where on Earth the impact will occur, based on a precise determination of its orbit.

    In June 2018, the small 3m (10ft) asteroid 2018 LA was discovered by a ground-based observatory in Arizona eight hours before impact. The Center for Near-Earth Object Studies at Nasa’s Jet Propulsion Laboratory (JPL) then made a precision determination of its orbit, which was used to calculate a probable impact location.


    This showed the rock was likely to hit southern Africa.

    Just as the calculation suggested, a fireball was recorded over Botswana by security camera footage on a farm. Fragments of the object were later found in the area.

    4
    Japan’s Himawari satellite captures the fireball’s steep descent. Himawari/JMA/@simon_sat

    How can monitoring be improved?

    The latest event over the Bering Sea shows that larger objects can collide with us without warning, underlining the need for enhanced monitoring.

    A more robust network would be dependent not only on ground telescopes, but space-based observatories also.

    A mission concept in development would see a telescope called NeoCam launched to a gravitational balance point in space, where it would discover and characterise potentially hazardous asteroids larger than 140m.

    Dr Amy Mainzer, chief scientist on NeoCam at JPL, said: “The idea is really to get as close as possible to reaching that 90% goal of finding the 140m and larger near-Earth asteroids given to Nasa by Congress.

    She said that if the mission did not launch, projections suggested it would “take us many decades to get there with the existing suite of ground-based surveys”.

    Dr Mainzer added: “But if you have an IR-based (infrared) telescope, it goes a lot faster.”

    See the full article here .

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  • richardmitnick 7:16 am on October 12, 2017 Permalink | Reply
    Tags: , , , BBC, , ,   

    From BBC: “Jodrell Bank bids for Unesco World Heritage status” 

    BBC
    BBC

    1
    The 76m (250ft) Mark I telescope was the largest steerable dish in the world when it was completed in 1957. PA

    Jodrell Bank Observatory has been selected as the latest UK candidate for World Heritage status.

    The site, in Cheshire, is home to the famous Lovell Telescope, which was complete in 1957.

    If the bid is successful, it would join the likes of Stonehenge and the Taj Mahal on the Unesco list of “globally important” landmarks.

    Prof Teresa Anderson, director of the observatory’s Discovery Centre, said it has a “rich scientific heritage”.

    She described the telescope, which was the largest of its kind when it was built, as “an icon for science”.

    More than 1,000 places around the world have been granted Unesco World Heritage status.

    Currently, 31 sites in the UK and its overseas territories have been awarded the accolade.

    2
    Professor Bernard Lovell (right) with structural engineer Charles Husband, who designed and constructed the Lovell Radio Telescope. PA

    The site was first used for radio astronomy in 1945 by Sir Bernard Lovell and his team and since then, its astronomers have tracked Sputnik and discovered quasars.

    Prof Anderson said her team have been preparing the case for years, “so it’s absolutely fantastic to reach this milestone”.

    Director of the Centre for Astrophysics, Prof Michael Garrett, said: “Jodrell Bank has played a leading role in radio astronomy for over seventy years, work which is reflected in the landscape of the site.”

    What is radio astronomy?

    3
    No image credit.

    Radio astronomy is the observation of radio waves that are emitted from celestial bodies, such as distant galaxies or stars
    Many strong sources of radio waves are invisible in normal light, so looking at radio waves reveals a completely different picture of the universe
    Radio waves are better at travelling long distances than shorter wavelengths, so can provide a clearer “view” of very distant objects than can be gathered using normal light
    Though the information gathered by radio telescopes is not in a visible form, it can be processed by computers to create images

    See the full article here .

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  • richardmitnick 3:55 pm on June 2, 2017 Permalink | Reply
    Tags: , BBC, Boeing-built ViaSat-2, Euroconsult, Eutelsat 172B along for the ride, The most powerful commercial broadband satellite ever built has just gone into orbit on an Ariane rocket., The US, ViaSat-2: Satellite goliath goes into orbit   

    From BBC: “ViaSat-2: Satellite goliath goes into orbit” 

    BBC
    BBC

    6.1.17
    Jonathan Amos

    1
    The Ariane lifted away from its pad during a tropical rain shower.

    The most powerful commercial broadband satellite ever built has just gone into orbit on an Ariane rocket.

    ViaSat-2, which is to be stationed above the Americas, has a total throughput capacity of about 300 gigabits per second.

    The spacecraft was part of a dual payload on the Ariane flight. It was joined by Eutelsat 172B, a UK/French-built platform to go over the Pacific.

    Both satellites will be chasing the rampant market for wi-fi on aeroplanes.

    Airlines are currently in a headlong rush to equip their fleets with connections that will allow passengers to use their mobile devices in mid-air.

    More than 6,000 commercial aircraft worldwide were offering an onboard wi-fi service in 2016; it is expected more than 17,000 will be doing so by 2021.

    In-flight internet has traditionally had a terrible reputation, but there is a feeling now that the latest technology really can give passengers a meaningful slice of bandwidth and at a competitive price.

    Inmarsat rides SpaceX Falcon

    Intelsat rolls out next-gen system

    2
    Artwork: ViaSat-2 will be positioned 36,000km above the equator at 69 degrees West

    The Ariane left the Kourou spaceport in French Guiana at 20:45 local time, Thursday (23:45 GMT), ejecting the satellites into their transfer orbits about half an hour later.

    Both must now get themselves into their final positions. Noteworthy is the fact that ViaSat-2 and 172B will be using electric engines to do this.

    These work by accelerating and expelling ions at high speed. The process provides less thrust than a standard chemical engine, but saves substantially on propellant mass.

    3
    Eutelsat-172B is the first satellite from Airbus to use all-electric propulsion for orbit-raising and station-keeping

    That saving can be traded to get either a lower-priced launch ticket, or to pack even greater capacity into the satellite’s communications payload for no additional weight.

    The US, Boeing-built ViaSat-2 uses a mix of chemical and electric propulsion, but Eutelsat’s platform is all-electric – the first such design to come from Europe’s biggest space manufacturer, Airbus.

    ViaSat-2 will be providing broadband services to fixed customers across North America, Central America, the Caribbean, and a portion of northern South America.

    But the satellite is also configured to service planes and ships, and in particular it is looking to grab a significant share of business out over the Atlantic.

    The aviation sector currently is a key battleground for satellite operators; it is where they are seeing double-digit growth.

    In the US, working with airlines such as JetBlue, ViaSat has already found success through its existing high-throughput ViaSat-1 spacecraft.

    With the extra capacity on ViaSat-2, it aims to do better still.

    “We think people want to use their devices in the air the way they do on the ground; that’s the bet we’ve made,” said ViaSat Chief Operating Officer Rick Baldridge.

    “JetBlue delayed their in-flight wi-fi offering, waiting for us, and now they’re giving it away for free and we’re providing 12 megabits per second to every seat, including streaming video,” he told BBC News.

    ViaSat-2’s “footprint” touches the western coast of Europe, but aeroplanes travelling further east will be handed seamlessly to a better-positioned Eutelsat spacecraft, which should enable passengers to stay connected all the way across to Turkey if needs be.

    This is one of the benefits of the strategic alliance that the two satellite companies have formed. And in time this will see the pair operate a ViaSat-3 platform together over Europe. This spacecraft is being built to have a total throughput capacity of one terabit per second.

    4
    172B has a 3D printed bracket (far right) holding an antenna to the satellite. This component is 35% lighter than the conventionally produced bracket (far left). AIRBUS DS.

    From its position very close to the International Date Line, Eutelsat’s 172B spacecraft is going to target – amongst other business – the flight corridors of the Asia-Pacific region. And it has some very smart British technology to do this in the form of a multi port amplifier.

    This can flexibly switch power between the satellite’s 11 spot beams to make sure the available bandwidth is always focused where it is needed most – whether that be on the planes moving east-west from Japan to California, say, or when they go in the other direction as a cluster at a different time of day.

    “To oversimplify, in-flight connectivity has mostly been restricted to the US. But now it is expanding into the Asia-Pacific region and it’s also coming to Europe,” said Rodolphe Belmer, Eutelsat’s chief executive officer.

    “We see spontaneous demand from airlines and it’s booming. It’s true the technology hasn’t always delivered, but you will see with the introduction of very high throughput satellites in the next few years that we will be able to… bring a massive quantity of bandwidth onboard the plane, meaning you can stream Netflix in HD. That’s a game-changer.”

    4
    In-flight connectivity is a key battleground for the satellite operators. Getty Images.

    Euroconsult is one of the world’s leading analyst groups following the satellite industry. Its research confirms the rapid growth now taking place, and says this will only accelerate.

    Euroconsult’s recent report on in-flight-connectivity (IFC) predicted nearly half of all commercial planes would be enabled by 2021, pushing revenues for the suppliers of onboard services from $1bn to $6.5bn inside 10 years. But Euroconsult’s CEO, Pacôme Revillon, said there will be winners and losers in this IFC race and this would likely be decided in the very near future.

    “Going to 2020, approximately 50% of aircraft could have opted for their chosen connectivity solutions, and certainly all of the major airlines will have made that choice. By that stage the market share could decide who are the winners and losers, and we anticipate seeing some consolidation in this sector, with two to three companies coming to dominate the market,” he told BBC News.

    See the full article here .

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  • richardmitnick 12:51 pm on April 16, 2017 Permalink | Reply
    Tags: BBC, Zoroastrianism   

    From BBC: “The Obsecure Religion that shaped the West” A Little Diversion on Easter and Passover 

    BBC
    BBC

    6 April 2017
    Joobin Bekhrad

    It has influenced Star Wars and Game of Thrones – and characters as diverse as Voltaire, Nietzsche and Freddie Mercury have cited it as an inspiration. So what is Zoroastrianism? Joobin Bekhrad finds out.

    1

    Talk of ‘us’ and ‘them’ has long dominated Iran-related politics in the West. At the same time, Christianity has frequently been used to define the identity and values of the US and Europe, as well as to contrast those values with those of a Middle Eastern ‘other’. Yet, a brief glance at an ancient religion – still being practised today – suggests that what many take for granted as wholesome Western ideals, beliefs and culture may in fact have Iranian roots.

    It is generally believed by scholars that the ancient Iranian prophet Zarathustra (known in Persian as Zartosht and Greek as Zoroaster) lived sometime between 1500 and 1000 BC. Prior to Zarathustra, the ancient Persians worshipped the deities of the old Irano-Aryan religion, a counterpart to the Indo-Aryan religion that would come to be known as Hinduism. Zarathustra, however, condemned this practice, and preached that God alone – Ahura Mazda, the Lord of Wisdom – should be worshipped. In doing so, he not only contributed to the great divide between the Iranian and Indian Aryans, but arguably introduced to mankind its first monotheistic faith.

    The idea of a single god was not the only essentially Zoroastrian tenet to find its way into other major faiths, most notably the ‘big three’: Judaism, Christianity and Islam. The concepts of Heaven and Hell, Judgment Day and the final revelation of the world, and angels and demons all originated in the teachings of Zarathustra, as well as the later canon of Zoroastrian literature they inspired. Even the idea of Satan is a fundamentally Zoroastrian one; in fact, the entire faith of Zoroastrianism is predicated on the struggle between God and the forces of goodness and light (represented by the Holy Spirit, Spenta Manyu) and Ahriman, who presides over the forces of darkness and evil. While man has to choose to which side he belongs, the religion teaches that ultimately, God will prevail, and even those condemned to hellfire will enjoy the blessings of Paradise (an Old Persian word).

    How did Zoroastrian ideas find their way into the Abrahamic faiths and elsewhere? According to scholars, many of these concepts were introduced to the Jews of Babylon upon being liberated by the Persian emperor Cyrus the Great. They trickled into mainstream Jewish thought, and figures like Beelzebub emerged. And after Persia’s conquests of Greek lands during the heyday of the Achaemenid Empire, Greek philosophy took a different course. The Greeks had previously believed humans had little agency, and that their fates were at the mercy of their many gods, who often acted according to whim and fancy. After their acquaintance with Iranian religion and philosophy, however, they began to feel more as if they were the masters of their destinies, and that their decisions were in their own hands.

    Though it was once the state religion of Iran and widely practised in other regions inhabited by Persian peoples (eg Afghanistan, Tajikistan and much of Central Asia), Zoroastrianism is today a minority religion in Iran, and boasts few adherents worldwide. The religion’s cultural legacy, however, is another matter. Many Zoroastrian traditions continue to underpin and distinguish Iranian culture, and outside the country, it has also had a noted impact, particularly in Western Europe.

    Zoroastrian rhapsody

    Centuries before Dante’s Divine Comedy, the Book of Arda Virafdescribed in vivid detail a journey to Heaven and Hell. Could Dante have possibly heard about the cosmic Zoroastrian traveller’s report, which assumed its final form around the 10th Century CE? The similarity of the two works is uncanny, but one can only offer hypotheses.

    Elsewhere, however, the Zoroastrian ‘connection’ is less murky. The Iranian prophet appears holding a sparkling globe in Raphael’s 16th Century School of Athens. Likewise, the Clavis Artis, a late 17th/early 18th-Century German work on alchemy was dedicated to Zarathustra, and featured numerous Christian-themed depictions of him. Zoroaster “came to be regarded [in Christian Europe] as a master of magic, a philosopher and an astrologer, especially after the Renaissance,” says Ursula Sims-Williams of the School of Oriental and African Studies at the University of London.

    Today, mention of the name Zadig immediately brings to mind the French fashion label Zadig & Voltaire. While the clothes may not be Zoroastrian, the story behind the name certainly is. Written in the mid-18th Century by none other than Voltaire, Zadigtells the tale of its eponymous Persian Zoroastrian hero, who, after a series of trials and tribulations, ultimately weds a Babylonian princess. Although flippant at times and not rooted in history, Voltaire’s philosophical tale sprouted from a genuine interest in Iran also shared by other leaders of the Enlightenment. So enamoured with Iranian culture was Voltaire that he was known in his circles as ‘Sa’di’. In the same spirit, Goethe’s West-East Divan, dedicated to the Persian poet Hafez, featured a Zoroastrian-themed chapter, while Thomas Moore lamented the fate of Iran’s Zoroastrians in Lalla Rookh.

    It wasn’t only in Western art and literature that Zoroastrianism made its mark; indeed, the ancient faith also made a number of musical appearances on the European stage.

    In addition to the priestly character Sarastro, the libretto of Mozart’s The Magic Flute is laden with Zoroastrian themes, such as light versus darkness, trials by fire and water, and the pursuit of wisdom and goodness above all else. And the late Farrokh Bulsara – aka Freddie Mercury – was intensely proud of his Persian Zoroastrian heritage. “I’ll always walk around like a Persian popinjay,” he once remarked in an interview, “and no one’s gonna stop me, honey!” Likewise, his sister Kashmira Cooke in a 2014 interview reflected on the role of Zoroastrianism in the family. “We as a family were very proud of being Zoroastrian,” she said. “I think what [Freddie’s] Zoroastrian faith gave him was to work hard, to persevere, and to follow your dreams.”

    Ice and fire

    When it comes to music, though, perhaps no single example best reflects the influence of Zoroastrianism’s legacy than Richard Strauss’ Thus Spoke Zarathustra, which famously provided the booming backbone to much of Stanley Kubrick’s 2001: A Space Odyssey. The score owes its inspiration to Nietzsche’s magnum opus of the same name, which follows a prophet named Zarathustra, although many of the ideas Nietzsche proposes are, in fact, anti-Zoroastrian. The German philosopher rejects the dichotomy of good and evil so characteristic of Zoroastrianism – and, as an avowed atheist, he had no use for monotheism at all.

    Freddie Mercury and Zadig & Voltaire aside, there are other overt examples of Zoroastrianism’s impact on contemporary popular culture in the West. Ahura Mazda served as the namesake for the Mazda car company, as well as the inspiration for the legend of Azor Ahai – a demigod who triumphs over darkness – in George RR Martin’s Game of Thrones, as many of its fans discovered last year. As well, one could well argue that the cosmic battle between the Light and Dark sides of the Force in Star Wars has, quite ostensibly, Zoroastrianism written all over it [cf. also the Essenic Dead Sea Scrolls for Sons of Light and Sons of Darkness and the battle of Armegeddon, the coming of the Messiah].

    For all its contributions to Western thought, religion and culture, relatively little is known about the world’s first monotheistic faith and its Iranian founder. In the mainstream, and to many US and European politicians, Iran is assumed to be the polar opposite of everything the free world stands for and champions. Iran’s many other legacies and influences aside, the all but forgotten religion of Zoroastrianism just might provide the key to understanding how similar ‘we’ are to ‘them’.

    1
    Zoroastrians believe there is one God called Ahura Mazda (Wise Lord) and He created the world.

    Zoroastrians believe that the elements are pure and that fire represents God’s light or wisdom.

    Ahura Mazda revealed the truth through the Prophet, Zoroaster.

    Zoroastrians traditionally pray several times a day.

    Zoroastrians worship communally in a Fire Temple or Agiary.

    The Zoroastrian book of Holy Scriptures is called The Avesta.

    The Avesta is the oldest and core part of the scriptures, which contains the Gathas. The Gathas are seventeen hymns thought to be composed by Zoroaster himself.

    The Younger Avesta – commentaries to the older Avestan written in later years. It also contains myths, stories and details of ritual observances.

    Zoroaster consistently contrasts these two peoples as the People of Righteousness ( asha ) and the People of the Lie ( druj ).

    2
    This expression is repeated many times in the Hasidic text The Tanya by Rabbi Schneur Zalmon of Liadi, the founder of Chabad

    See the full article here .

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  • richardmitnick 4:05 pm on February 18, 2017 Permalink | Reply
    Tags: BBC,   

    From BBC: “Gravity probe exceeds performance goals” 

    BBC
    BBC

    2.18.17
    Jonathan Amos

    ESA/LISA Pathfinder
    ESA/LISA Pathfinder

    The long-planned LISA space mission to detect gravitational waves looks as though it will be green lit shortly.

    Scientists working on a demonstration of its key measurement technologies say they have just beaten the sensitivity performance that will be required.

    The European Space Agency (Esa), which will operate the billion-euro mission, is now expected to “select” the project, perhaps as early as June.

    The LISA venture intends to emulate the success of ground-based detectors.

    LIGO bloc new
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo Hanford, WA, USA installation
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA
    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    These have already witnessed the warping of space-time that occurs when black holes 10-20 times the mass of the Sun collide about a billion light-years from Earth.

    LISA, however, aims to detect the coming together of truly gargantuan black holes, millions of times the mass of the Sun, all the way out to the edge of the observable Universe.

    Researchers will use this information to trace the evolution of the cosmos, from its earliest structures to the complex web of galaxies we see around us today.

    The performance success of the measurement demonstration was announced here in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS).

    It occurred on Esa’s LISA “Pathfinder” (LPF) spacecraft that has been flying for just over a year.

    This probe is trialling parts of the laser interferometer that will eventually be used to detect passing gravitational waves.

    When Pathfinder’s instrumentation was set running it was hoped it would get within a factor of 10 of the sensitivity that would ultimately be needed by the LISA mission, proper.

    In the event, LPF not only matched this mark, but went on to exceed it after 12 months of experimentation.

    “You can do the full science of LISA just based on what LPF has got. And that’s thrilling; it really is beyond our dreams,” Prof Stefano Vitale, Pathfinder’s principal investigator, told BBC News.

    2
    LIGO

    Gravitational waves are a prediction of the Theory of General Relativity
    It took decades to develop the technology to directly detect them
    They are ripples in the fabric of space and time produced by violent events
    Accelerating masses will produce waves that propagate at the speed of light
    Detectable sources ought to include merging black holes and neutron stars
    LIGO fires lasers into long, L-shaped tunnels; the waves disturb the light
    Detecting the waves opens up the Universe to completely new investigations

    The first detection of gravitational waves at the US LIGO laboratories in late 2015 has been described as one of the most important physics breakthroughs in decades.

    Being able to sense the subtle warping of space-time that occurs as a result of cataclysmic events offers a completely new way to study the Universe, one that does not depend on traditional telescope technology.

    Rather than trying to see the light from far-off events, scientists would instead “listen” to the vibrations these events produce in the very fabric of the cosmos.

    LIGO achieved its success by discerning the tiny perturbations in laser light that was bounced between super-still mirrors suspended in kilometres’ long, vacuum tunnels.

    LISA would do something very similar, except its lasers would bounce between free-floating gold-platinum blocks carried on three identical spacecraft separated by 2.5 million km.

    4
    A cutaway impression of the laser interferometer system inside Lisa Pathfinder. ESA.

    Lisa Pathfinder’s payload is a laser interferometer, which measures the behaviour of two free-falling blocks made from a platinum-gold alloy
    Placed 38cm apart, these “test masses” are inside cages that are very precisely engineered to insulate them against all disturbing forces
    When this super-quiet environment is maintained, the falling blocks will follow a “straight line” that is defined only by gravity
    It is under these conditions that a passing gravitational wave would be noticed by ever so slightly changing the separation of the blocks
    Lisa Pathfinder has demonstrated sub-femtometre sensitivity, but the satellite cannot itself make a detection of the ripples
    To do this, a space-borne observatory would need to reproduce the same performance with blocks positioned 2.5 million km apart

    In both cases, the demand is to characterise fantastically small accelerations in the measurement apparatus as it squeezed and stretched by the passing gravitational waves.

    For LISA the projected standard is to characterise movements down below the femto-g level – a millionth of a billionth of the acceleration a falling apple experiences at Earth’s surface; and to do that over periods of minutes to hours.

    LISA Pathfinder has just succeeded in achieving sub-femto sensitivity over timescales of half a day. Getting stability at the lowest frequencies is very important.

    “The lower the frequency to which you go, the bigger are the bodies that generate gravitational waves; the more intense are the gravitational waves; and the more far away are the bodies. So, the lower the frequencies, the deeper into the Universe you go,” explained Prof Vitale, who is affiliated to Italian the Institute for Nuclear Physics and University of Trento.

    To be clear, LPF cannot itself detect gravitational waves because the “arm length” of the system has been shrunk down from 2.5 million km to just 38 cm – to be able to fit inside a single demonstration spacecraft – but it augurs well for the full system.

    ESA/eLISA
    ESA/eLISA

    Esa recently issued a call for proposals to fly a gravitational science mission in 2034. The BBC understands the agency received only one submission – from the LISA Consortium.

    This is unusual. Normally such calls attract a number of submissions from several groups all with different ideas for a mission. But in this instance, it is maybe not so surprising given that the LISA concept has been investigated for more than two decades.

    Prof Karsten Danzmann, co-PI on LPF and the lead proposer of LISA, hopes a way can be found to fly his consortium’s three-spacecraft detection system earlier than 2034, perhaps as early as 2029. But that requires sufficient money being available.

    “The launch date is only programatically dominated, not technically,” Prof Danzmann told BBC News.

    “And with all the interest in gravitational waves building up right now, ways will be found to fly almost simultaneously with Athena (Europe’s next-generation X-ray telescope slated to launch in 2028).

    ESA Athena spacecraft
    ESA/Athena spacecraft

    “This would make perfect sense because we can tell the X-ray guys where to look, because we get the alert of any bright (black hole) merger immediately, and then we can tell them, ‘look in the next hour and you’ll see an X-ray flash’.”

    “That would be tremendously exciting to do multi-messenger astronomy with LISA and Athena at the same time.”

    LISA could be selected as a confirmed project at Esa’s Science Programme Committee in June. There would then be a technical review followed by parallel industrial studies to assess the best, most cost-effective way to construct the mission.

    Agreement will also be sought with the Americans to bring them onboard. They are likely to contribute about $300-400m of the overall cost in the form of components, such as the lasers that will be fired between LISA’s trio of spacecraft.

    The LPF demonstration experiments are due to end in May, or June at the latest.

    See the full article here .

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  • richardmitnick 3:16 pm on February 16, 2017 Permalink | Reply
    Tags: BBC, ,   

    From BBC: “Event Horizon Telescope ready to image black hole” 

    BBC
    BBC

    2.16.17
    Jonathan Amos

    1
    The EHT team has produced simulations of what Einstein’s theories predict the hole should look like. Hotaka Shiokawa/CFA/HARVARD

    Scientists believe they are on the verge of obtaining the first ever picture of a black hole.

    They have built an Earth-sized “virtual telescope” by linking a large array of radio receivers – from the South Pole, to Hawaii, to the Americas and Europe.

    There is optimism that observations to be conducted during 5-14 April could finally deliver the long-sought prize.

    In the sights of the so-called “Event Horizon Telescope” will be the monster black hole at the centre of our galaxy.

    Here is the Event Horizon Telescope Array

    Event Horizon Telescope map

    The locations of the radio dishes that will be part of the Event Horizon Telescope array. Image credit: Event Horizon Telescope sites, via University of Arizona at https://www.as.arizona.edu/event-horizon-telescope.

    Arizona Radio Observatory
    Arizona Radio Observatory/Submillimeter-wave Astronomy (ARO/SMT)

    ESO/APEX
    Atacama Pathfinder EXperiment (APEX)

    CARMA Array no longer in service
    Combined Array for Research in Millimeter-wave Astronomy (CARMA)

    Atacama Submillimeter Telescope Experiment (ASTE)
    Atacama Submillimeter Telescope Experiment (ASTE)

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

    IRAM NOEMA interferometer
    Institut de Radioastronomie Millimetrique (IRAM) 30m

    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA
    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Hawaii SAO
    Submillimeter Array Hawaii SAO

    Future Array/Telescopes

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array, Chile

    Plateau de Bure interferometer
    Plateau de Bure interferometer

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL

    Sag A*  NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way
    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    Although never seen directly, this object, catalogued as Sagittarius A*, has been determined to exist from the way it influences the orbits of nearby stars.

    These race around a point in space at many thousands of km per second, suggesting the hole likely has a mass of about four million times that of the Sun.

    But as colossal as that sounds, the “edge” of the black hole – the horizon inside which an immense gravity field traps all light – may be no more than 20 million km or so across.

    And at a distance of 26,000 light-years from Earth, this makes Sagittarius A* a tiny pinprick on the sky.

    The Event Horizon Telescope (EHT) team is nonetheless bullish.

    “There’s great excitement,” said project leader Sheperd Doeleman from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

    “We’ve been fashioning our virtual telescope for almost two decades now, and in April we’re going to make the observations that we think have the first real chance of bringing a black hole’s event horizon into focus,” he told BBC News.

    EHT map

    2
    The eventual EHT array will have 12 widely spaced participating radio facilities

    The EHT’s trick is a technique called very long baseline array interferometry (VLBI).

    This combines a network of widely spaced radio antennas to mimic a telescope aperture that can produce the resolution necessary to perceive a pinprick on the sky.

    The EHT is aiming initially to get down to 50 microarcseconds. Team-members talk in analogies, describing the sharpness of vision as being the equivalent of seeing something the size of a grapefruit on the surface of the Moon.

    They emphasise the still complex years of work ahead, but also trail the prospect of an imminent breakthrough.

    The scientists certainly have an expectation of what they ought to see, if successful.

    Simulations rooted in Einstein’s equations predict a bright ring of light fringing a dark feature.

    The light would be the emission coming from gas and dust accelerated to high speed and torn apart just before disappearing into the hole.

    The dark feature would be the shadow the hole casts on this maelstrom.

    “Now, it could be that we will see something different,” Doeleman said.

    “As I’ve said before, it’s never a good idea to bet against Einstein, but if we did see something that was very different from what we expect we would have to reassess the theory of gravity.

    “I don’t expect that is going to happen, but anything could happen and that’s the beauty of it.”

    Over the years, more and more radio astronomy facilities have joined the project. A key recent addition is the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

    Its extraordinary state-of-the-art technology has at a stroke increased the EHT’s sensitivity by a factor of 10. Hence, the optimism ahead of April.

    Even so, scientists have had to install special equipment at all the radio facilities involved in the observations.

    This includes big hard drives to store colossal volumes of data, and atomic clocks to precisely timestamp it all.

    Nothing happens on the spot – the hard drives must first be flown to a large computing facility at MIT Haystack Observatory in Westford, just outside Boston, Massachusetts.

    “Our hard-drive modules hold the capacity of about 100 standard laptops,” said Haystack’s Vincent Fish.

    “We have multiple modules at each telescope and we have numerous telescopes in the array. So, ultimately, we’re talking about 10,000 laptops of data.”

    It is in Haystack’s correlator computer that the synthesis will begin.

    Some very smart imaging algorithms have had to be developed to make sense of the EHT’s observations, but it will not be a quick result.

    It could be the end of the year, perhaps the start of 2018, before the team releases an image in public.

    3
    All the data from the telescopes will be brought to MIT Haystack to be ingested in its correlator computer.

    Looking to the future, the scientists are already thinking about how to extend their techniques.

    For example, the matter closest to the event horizon and about to disappear into Sagittarius A* should take about 30 minutes to complete an orbit.

    Katie Bouman, from MIT’s Computer Science and Artificial Intelligence Laboratory, thinks it might be possible to capture this movement.

    “We want to push boundaries and to try to make movies from the data,” she told BBC News.

    “Maybe we can actually see some of the gas flowing around the black hole. That’s really the next stage of what we’re trying to accomplish with these imaging algorithms.”

    First and foremost, the team needs good weather at the participating observing stations in April.

    The strategy is to view the galactic centre at a wavelength of 1.3mm (230GHz). This has the best chance of piercing any obscuring gas and dust in the vicinity of the black hole. But if there is too much water vapour above the array’s receivers, the EHT will struggle even to see through Earth’s atmosphere.

    Just getting a resolved view of Sagittarius A* would be a remarkable triumph in itself. But the real objective here is to use the imaging capability to go test aspects of general relativity.

    If there are flaws to be found in Einstein’s ideas – and scientists suspects there are more complete explanations of gravity out there waiting to be discovered – then it is in the extreme environment of black holes that limitations should be exposed.

    See the full article here .

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  • richardmitnick 12:45 pm on November 28, 2016 Permalink | Reply
    Tags: , , BBC, ,   

    From BBC: “Disturbing the peace: Can America’s quietest town be saved?” 

    BBC
    BBC

    26 November 2016
    Dave Lee

    gbo-logo

    GBO radio telescope, West Virginia, USA

    There’s a town in West Virginia where there are tight restrictions on mobile signal, wifi and other parts of what most of us know as simply: modern life. It means Green Bank is a place unlike anywhere else in the world. But that could be set to change.

    “Do you ever sit awake at night and wonder, what if?” I asked.

    Mike Holstine’s eyes twinkled like the stars he had spent his life’s work observing.

    “The universe is so huge,” he began.

    “On the off chance we do get that hugely lucky signal, when we look in the right place, at the right frequency. When we get that… can you imagine what that’s going to do to humankind?”

    Holstine is business manager at the Green Bank Observatory, the centrepiece of which is the colossal Green Bank Telescope. On a foggy Tuesday morning, I’m standing in the middle of it, looking up, feeling small.

    Though the GBT has many research tasks, the one everyone talks about is the search for extra-terrestrial intelligence. The GBT listens out for signs of communication or activity by species that are not from Earth.

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    Unique people

    I am not the first BBC reporter to pop in here. In fact, Green Bank is a source of constant fascination for journalists all over the world. Recently, several people in the town told me, a Japanese crew baffled everyone when it appeared to set up a game show-style challenge in the area.

    Outsiders come here for two reasons. One, to marvel at the science. Two, to ogle at the unique people who have chosen to live here.

    Green Bank sits at the heart of the National Radio Quiet Zone, a 13,000 square mile (33,669 sq km) area where certain types of transmissions are restricted so as not to create interference to the variety of instruments set up in the hills – as well as the Green Bank Observatory, there is also Sugar Grove, a US intelligence agency outpost.

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    Joel Bradshaw, 28 October 2009

    For those in the immediate vicinity of the GBT, the rules are more strict. Your mobile phone is useless here, you will not get a TV signal and you can’t have strong wi-fi  - though they admit this is a losing battle. Modern life is winning, gradually. And newer wi-fi standards do not interfere with the same frequencies as before.

    But this relative digital isolation has meant that Green Bank has become a haven for those who feel they are quite literally allergic to electronic interference.

    The condition is referred to as electromagnetic hypersensitivity disorder. Opinion is split on whether it is real, with the majority of medical opinion erring on the side that it is more psychological than physical.

    But when I met with Diane Schou, one sufferer, I realised it did not matter whether the condition was “real” or not  –  for a growing number of people, modern technology has them feeling trapped.

    The knock-on effects from the global recession have led to the Green Bank Telescope being on the chopping block.

    The National Science Foundation (NSF) is consulting right now on whether they can justify the expense of the telescope. To make things more precarious for Green Bank, other telescopes with similar abilities have been built in other parts of the world, including Chile.

    The NSF is not going to just pull the rug from underneath the GBT. As it stands, funding is going to be gradually removed. Not a slow death, but rather a chance for Mr Holstine to court private investment money to keep the telescope operational.

    It is working so far  –  the Breakthrough Listen project, backed with Silicon Valley money, is focused solely on finding other intelligent life. Over 10 years, its investors are planning to spend $100m (£80.3m) on the quest. They are using the GBT as part of an effort to survey the one million stars closest to Earth.

    For the locals in Green Bank, the survival of the telescope is not just about seeking ET. It is also the largest employer in the entire county.

    The big questions

    When I asked Chuck and Heather Niday, who host a weekly show on the charming Allegheny Mountain Radio, whether the town would change if restrictions were lifted, they were reserved.

    Sure, the kids would love access to Snapchat. But the fabric of the town would not be affected. It is a rural community and no amount of mobile phone signal will change the nature of this tight-knit town.

    If like me you find it unfathomable that we are alone in the universe, then Green Bank is an utterly essential utility. When I asked Mr Holstine to justify the money the US government spends on the facility, he dug deep.

    “How many of us have walked out into the night and looked up at the stars and stood there in wonder?

    “We don’t produce widgets. We don’t produce something that you go to the store and buy. But we do produce education. We do produce research. We do produce answers to questions we haven’t even asked ourselves yet.

    “Those questions are the basis of what it means for us to be human. That constant search is done right here every day.”

    See the full article here .

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  • richardmitnick 9:11 am on April 21, 2016 Permalink | Reply
    Tags: , BBC, ,   

    From BBC: “Pressure grows for price on carbon ahead of UN signing” 

    BBC
    BBC

    4.21.16
    Matt McGrath

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    India is calling for a tax on coal to help adaptation to climate change

    A group of world leaders and international finance chiefs has urged the world to rapidly expand the pricing of carbon pollution.

    They argue that more than half of emissions of CO2 should be covered by a carbon price within a decade.

    India has also called on rich countries to put a tax on coal to help poorer nations adapt to climate change.

    These calls came ahead of a UN ceremony where some 155 countries are expected to sign the Paris Climate Agreement.

    Race to ratify the Paris climate deal

    Putting an effective price on carbon has long been the favourite method of most economists in dealing with climate change.

    In 2006 Sir Nicholas Stern’s landmark review of the costs of climate change found that establishing a carbon price was essential to dealing effectively with the problem.

    Cap, trade or tax

    Since then attempts have been made, with mixed success. These have included cap and trade schemes in many parts of the world, where a limit on emissions is established by governments and permits are issued to heavy carbon users. If they cut back on their emissions they can trade the permits on the market.

    Schemes like this have been criticised for being too generous to polluters, often issuing them with free permits. The European Union’s flagship Emissions Trading Scheme almost collapsed because of this practice in recent years.

    Other countries have adopted a more straightforward carbon tax as a means of getting polluters to cut back.

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    So far around 12% of the world’s emissions are covered by such schemes. This new coalition of political leaders and financiers says that has to improve significantly if the world is to keep global temperature rises below 2 degrees.

    The group includes the Prime Ministers of Canada and Ethiopia, the Presidents of Chile, France and Mexico, the Chancellor of Germany and the head of the IMF and World Bank.

    They believe that the world can achieve 25% of emissions covered by carbon pricing by 2020 while half the world’s output could be covered by 2025.

    “There is a growing sense of inevitability about putting a price on carbon pollution,” said World Bank President Jim Yong Kim in a statement.

    “Prices for producing renewable energy are falling fast, and putting a price on carbon has the potential to make them even cheaper than fuels that pollute our planet.”

    Without giving too many details, the leaders believe that carbon pricing can be expanded in three ways – by increasing the number of governments putting a price on carbon, by deepening existing carbon pricing programs, and by promoting global cooperation.

    “We should now follow up the Paris Agreement with adequate actions, national policies, investment schemes and regional and international initiatives and partnerships, said Ethiopia’s Prime Minister Dessalegn.

    “I iterate Ethiopia’s commitment to the global efforts to overcome dangerous climate change and ensure sustainable development. We will use every policy instrument, including carbon pricing, which is found to be effective, efficient and fair.”
    Global coal tax?

    India was also keen to promote the idea of carbon pricing before the UN signing ceremony here in New York . They are promoting the idea of a tax on coal.

    The country recently increased its tax on mined coal to $6 a tonne, a significant increase from $1. India’s environment minister Prakasj Javadekar believes the world, especially the wealthier countries, should now follow suit.

    “If they follow India and levy a tax of $5-$6 a tonne on coal production, $100 billion can easily be mobilised,” he said, speaking to news agencies.

    Mr Javadekar said this would be a highly effective way of funding climate adaption in poor countries around the world while incentivising a transition to greener energy sources.

    See the full article here .

    Please help promote STEM in your local schools.

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