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  • richardmitnick 12:45 pm on November 28, 2016 Permalink | Reply
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    From BBC: “Disturbing the peace: Can America’s quietest town be saved?” 


    26 November 2016
    Dave Lee


    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.


    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.

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


    Matt McGrath

    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.


    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 .

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  • richardmitnick 4:25 pm on April 19, 2016 Permalink | Reply
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    From BBC: “Gravitational wave mission passes ‘sanity check’ “ 


    18 April 2016
    Jonathan Amos

    ESA/LISA Pathfinder
    ESA/LISA Pathfinder

    A European Space Agency [ESA] effort to try to detect gravitational waves in space is not only technically feasible but compelling, a new report finds.

    A panel of experts was asked to perform a “sanity check” on the endeavour, which is likely to cost well in excess of one billion euros.

    The Gravitational Observatory Advisory Team says it sees no showstoppers.

    It even suggests ESA try to accelerate the project from its current proposed launch date in 2034 to 2029.

    Whether that is possible is largely a question of funding. Space missions launch on a schedule that is determined by a programme’s budget.

    “But after submitting our report, ESA came back to us and asked what we thought might be technically possible, putting aside the money,” explained Goat chairman, Dr Michael Perryman.

    “We are in the process of finalising a note on that, which will suggest the third quarter of 2029. So, 13 years from now,” he told BBC News.

    The agency has stated its intention to build a mission that investigates the “gravitational Universe”, and is set to issue a call to the scientific community to submit a detailed proposal.

    Ripples in the fabric of space-time

    Artwork: Advanced Ligo detected coalescing black holes more than a billion light-years from Earth. NSF

    Caltech/MIT Advanced aLigo detector in Livingston, Louisiana
    Caltech/MIT Advanced aLigo detector in Livingston, Louisiana

    Gravitational waves are a prediction of the Theory of General Relativity
    Their existence had been inferred by science but only recently directly detected
    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 starsGravity mission passes ‘sanity check’
    Advanced Ligo fires lasers into long, L-shaped tunnels; the waves disturb the light
    Detecting the waves opens up the Universe to completely new investigations

    Gravitational waves – ripples in space-time – have become the big topic of conversation since their first detection last year by the ground-based Advanced LIGO facilities in the US.

    Using a technique known as laser interferometry, the labs sensed the fantastically small disturbance at Earth generated by the merger of two black holes more than a billion light-years away.

    The discovery opens up a completely new way to do astronomy, allowing scientists to probe previously impenetrable regions of the cosmos and to test some of the fundamental ideas behind general relativity – Einstein’s theory of gravity.

    The Goat says the stunning detection by aLIGO is a game-changer: “In a single step, gravitational wave astronomy has been placed on a secure observational footing, opening the panorama to the next robust steps in a space-based gravitational wave observatory.”

    That was not the case when the panel started its work. Then, there were many people who thought a detection might be beyond our measurement capability.

    The Goat believes that any space-borne observatory ESA might pursue should proceed using the same technical approach as aLigo – laser interferometry.

    aLIGO employs laser interferometers – the technology suggested also for a space mission. LIGO

    The agency is currently doing experiments in orbit that will prove some of the equipment needed on a future gravitational wave observatory. But the Goat also identifies critical additional developments that must now be prioritised to take the laser approach into space.

    That said, there is also encouraging support in the report for an alternative detection concept called atom interferometry. This is too immature at the moment to be a contender, the Goat says, but it could benefit from a technology demonstration mission in the near future.

    Since the 1980s, scientists have been working on a system to detect gravitational waves from orbit called LISA – the Laser Interferometer Space Antenna.

    It would fly a network of satellites separated by a few million kilometres.

    Lasers fired between these spacecraft would sense ripples in space-time generated by much more massive objects than the black holes seen by LIGO. LISA’s targets would be the monster black holes, millions of times the mass of our Sun, that coalesce when galaxies collide, for example.

    Future LISA: How many lasers can you fly?

    ESA is set to fly a mission dedicated to gravitational astronomy in the 2030s

    The available budget will determine the architecture of an operational Lisa mission. eLISA

    The current LISA design proposes a two-arm laser interferometer (left)
    But scientists would prefer to fly an architecture that has three arms (right)
    The latter could more easily locate gravitational wave sources in the sky
    Whether two or three arms are flown will depend on the available budget
    At present, ESA rules only permit a maximum 20% involvement from NASA
    But it may require a bigger US participation to get the full architecture

    LISA was previously proposed as a joint venture between Europe and the US.

    When the Americans then ran into funding difficulties and pulled out, scientists on the European side “de-scoped” the mission to try to make it fit within the financial envelope available at the time. Many commentators thought this revised design compromised the science to an unacceptable degree.

    Researchers on both sides of the Atlantic are now pushing hard to go back to the old arrangement.

    This potentially represents something of a headache for ESA’s hierarchy.

    Following the American withdrawal, the European Space Agency instigated a “rule” that foreign contributions to its missions should in future represent no more than 20% of the overall cost.

    The restriction was designed to ensure that no mission could be scuppered by a sudden change of heart from an international partner.

    But this financial ceiling may have to be broken if the US is to come back onboard and participate in the type of space mission that gravitational wave scientists most want to see fly.

    The Goat “suggests that such a mission will be more robust, and provide a greater science return per euro, if the US could consider a larger contribution, including a re-establishment of a meaningful collaboration.”

    The call to formally propose a new mission and its architecture should go out within the next 12 months.

    “It is to be determined precisely when, but within the year,” confirmed Dr Fabio Favata, head of ESA’s Science Planning and Community Coordination Office.

    “The call will ask the community to define a realistic mission in detail. In the meantime, we are already in discussions with our member states and NASA about who could do what, at least in the study phase. The implementation phase would take more time, of course.”

    ESA is already developing some technologies, but the Goat says others must now be prioritised. AIRBUS DS.

    See the full article here .

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  • richardmitnick 9:08 pm on December 14, 2015 Permalink | Reply
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    From BBC: “Jodrell Bank Observatory celebrates 70 years of radio astronomy” 


    14 December 2015

    The observatory originally used Army radar equipment, with the radio telescope being built later. University of Manchester

    The 70th anniversary of an astronomer’s first steps into a “whole new science” at one of Britain’s most important stargazing sites has been marked.

    Sir Bernard Lovell began using radio astronomy in 1945 at the opening of the fledgling Jodrell Bank Observatory.

    The Cheshire site would later become home to the iconic radio telescope which bears the astrophysicist’s name.

    Its director Prof Tim O’Brien said his work had given astronomers the chance to look at “the invisible universe”.

    The anniversary has been marked with the launch of a year-long programme of events celebrating “the past, present and future of Jodrell Bank’s science, engineering and heritage”, a spokeswoman said.

    In April, the site was chosen as the worldwide headquarters for the Square Kilometre Array project, which will probe the early universe, test the theory of gravity and even search for alien life.

    Prof O’Brien said that achievement was a direct result of Sir Bernard’s work, as he pioneered a “whole new science [through which] we discovered a whole new universe out there, full of super massive black holes, exploding stars and the fading glow of the Big Bang.

    Sir Bernard Lovell initially set up the observatory for a two-week period in 1945.

    The Mark I Telescope, which was renamed the Lovell Telescope in 1987, was built in the 1950s. University of Manchester

    The radio telescope, which is still used by astronomers, towers over the surrounding countryside. Mike Peel/University of Manchester

    Sir Bernard, who died in 2012, set up old Army radar equipment on the site to detect cosmic-rays and investigate meteors and began work on 14 December 1945.

    The huge Lovell Telescope was completed in 1957 and, during its first year, it was the only facility in the West able to track the rocket carrying the Russians’ first satellite, the Sputnik, into space.

    It went on to confirm the existence of pulsars – dying stars that send out pulses of electromagnetic radiation – in 1968 and, in 1979, was instrumental in proving Einstein’s theory of relativity for the first time.

    In 2006, it was named as Britain’s greatest unsung landmark in a BBC poll.

    What is radio astronomy?


    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, with even objects like the Sun and planets revealing new features when viewed with radio telescopes
    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 10:44 am on October 8, 2015 Permalink | Reply
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    From BBC: “Supernova ‘stream’ in neutrino lab’s sights” 


    2 October 2015
    Paul Rincon

    A global collaboration will aim to unravel the mysteries of neutrinos – also known as “ghost particles”.

    The Dune collaboration might observe neutrinos from a supernova in our galaxy – if luck is on their side

    Among the goals of the venture, formed earlier this year, will be to catch neutrino particles streaming towards us from a supernova – an exploding star.

    Such events occur about every 30 years, but the neutrino streams they produce have not been studied in detail.

    Dune (Deep Underground Neutrino Experiment) will be hosted at Fermilab in Batavia, Illinois.

    It will involve the development of the world’s most high-intensity beam of neutrinos, which will travel 1,300km (800mi) underground from Fermilab towards a massive detector instrument based at the Sanford Underground Research Facility [SURF] in South Dakota.

    Sanford Underground Research Facility Interior

    The venture is the product of a merger between European and US projects with similar aims. The international collaboration held its inaugural meeting at Fermilab in April.

    “There has been a process since last summer to prepare the ground for this collaboration, based on bringing together the US and European projects. There are now 700 people signed up,” said Prof Stefan Söldner-Rembold, from the University of Manchester.

    “The step forward is a new collaboration with a new name that has commitments from the US, Europe, India and other regions to go forward.”

    Neutrinos are one of some 17 elementary cosmic building blocks that make up the Universe. But they are also a source of intrigue for particle physicists.

    They are extremely light particles, with no electric charge and pass harmlessly through other matter. This property makes them very difficult to observe and is responsible for them being nicknamed “ghost particles”. Neutrinos may also play a role in the mystery of why the Universe came to consist mostly of matter rather than antimatter.


    They are found in three different states, or flavours, and the particles can flip from one flavour to another. Dune aims to carry out a detailed investigation of this three-flavour model of neutrino physics.

    The project will make use of an existing particle accelerator at Fermilab as a proton source, and then smash the beam into a so-called “target” made of a material that will engender the production of short-lived particles. These will travel about 200m through a decay pipe, and as they do, a large proportion will transform into neutrinos.

    Another potential scientific pay-off of the collaboration might be the opportunity to observe an exploding star in closer detail than ever before. But the team will need luck on their side, as it is dependent on a suitable event taking place during the lifetime of the project. It’s a game of chance, but scientists are hopeful the detector will catch one.

    The four 10-kilotonne detector modules will be filled with liquid argon. FNAL

    “If a supernova happens in our galaxy, which should happen once every 30 years or so, this experiment should – within seconds – see thousands of neutrino interactions,” said Prof Söldner-Rembold.

    “There was a supernova in 1987 and there were some neutrino detectors online – they saw something, which spurred a lot of interest at the time.

    This image shows the remnant of Supernova 1987A seen in light of very different wavelengths. ALMA data (in red) shows newly formed dust in the centre of the remnant. Hubble (in green) and Chandra (in blue) data show the expanding shock wave.

    ALMA Array

    NASA Hubble Telescope
    NASA/ESA Hubble

    NASA Chandra Telescope

    But a supernova with a detector like this, it is something that has never been observed.

    The “spillover” from a supernova would depend on how far away it was from Earth. But such an energetic event, close enough to Earth, could potentially send huge numbers of neutrinos streaming our way – to be picked up by detectors. This could potentially shed light on the mechanics of stellar explosions, and how these events evolve over time.

    Dune will also look for a hypothetical phenomenon known as proton decay. Protons are very stable sub-atomic particles; they have never been seen to transform into lighter cosmic building blocks.

    However, in some theories of particle physics, such as the still-unconfirmed framework known as supersymmetry, this should happen.

    “It’s the ultimate rare decay. It’s another way of looking for ‘new physics’, separate from the LHC, where you don’t need to go to high energies,” said Prof Söldner-Rembold.

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    Cern, the organisation that operates the Large Hadron Collider, is one of those that is now involved with Dune. The cost of the entire project is on the order of $1bn, but some international partners pay through in-kind contributions.

    The detectors will be filled with liquid argon, with the first of the four 10-kilotonne modules due to be installed in the 2020s. Neutrino collisions create electrons and flashes of light in the liquid argon, which leave observable traces of the neutrinos. The project is set to run for three decades.

    See the full article here .

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  • richardmitnick 4:37 pm on September 18, 2015 Permalink | Reply
    Tags: , BBC, Polar bears and survival   

    From BBC: “Sergey Ananov: Two days on ice with three polar bears” 


    Sergey Ananov

    In July Russian adventurer Sergey Ananov was forced to ditch his helicopter in icy waters between Canada and Greenland. Here he describes his two-day battle against high winds and extreme temperatures – and a few unexpected guests.

    I always feel very free, relaxed and happy when I’m flying helicopters and that was exactly how I was feeling shortly before 11:30 on 25 July.

    I was halfway through a six-hour flight from Iqaluit in Canada to Nuuk in Greenland. I was flying above a thick carpet of fog and underneath a bright canopy of cloud, steering my Robinson R22 through this fluffy grey corridor, quite alone in the world with the engine noise and a feeling of intense happiness. Next to me, in the passenger seat, sat an extra fuel tank that I had nicknamed Wilson, after the volleyball in Castaway. And 1,500ft (460m) below me – though I could not see it because of the fog – lay the ice and cold waters of the Davis Strait.

    Suddenly, I felt a jolt in the tail and I lost about half the power to the blades. The engine was running fine so I took it to signal a problem in transmission. The speed was dropping sharply – not good. I didn’t want to risk falling like a pebble out of the sky so I made the adjustments I needed to accelerate, which meant losing altitude. The helicopter was shaking and veering alarmingly to one side and within a few seconds it became clear to me that I would not be able to continue my flight.

    Sergey Ananov

    It was Day 42 of my solo attempt to become the first person to circumnavigate the world in a helicopter weighing less than one tonne.

    A thousand thoughts went through my head, among them this one: “Oh God, I have flown 34,000 miles and it’s only 4,000 more till I get my world record in Moscow.” And: “Why does this have to happen to me here, not above the swamps of Florida or the prairies of Canada or even somewhere in Siberia, where I would just be able to land, get out my phone and call for help?”

    I switched the helicopter on to auto-rotation, a safety mode that allows it to glide downwards. Dropping through the layer of fog, which was just 200 feet (60m) above the sea, I saw, out of the corner of my eye, an inviting lump of ice. But I was rapidly losing rotation and it would have been dangerous to try to extend the flight to reach it, so I headed straight for the water.

    I don’t agree with the word “crashed” that journalists are so fond of. It was not a crash. It was a forced landing on water, and it was a very controlled and soft one. I was completely unharmed.

    The helicopter’s tail sank immediately. I knew there was a danger that my weight would tip the aircraft on to my side – starboard – and trap me in deep water, so I threw my weight to my left to force the helicopter on to port side. It fell on that side and the blades, which were still turning, smashed to pieces on the surface.

    Then I undid my safety belt and opened the door. Instantly I was up to my neck in icy water. I was wearing a survival suit, but only around my legs and waist – the top part hung loose because I find it quite impossible to fly with one covering my arms and upper body. Such was my adrenaline at that moment that I didn’t feel the cold at all. I swam out of the helicopter and then dived back down to retrieve the life raft, which was stowed under my seat.

    Whenever I had mentally rehearsed a landing on water I had programmed my brain to think that the life raft was my first priority. It did save my life, though not in the way I imagined.

    It turned out I was just 50m or so from the lump of ice I had spotted before making my landing, and this was better than any inflatable raft. I swam over and climbed on to it. It was about 15-20m in diameter and would be my home for the foreseeable future. By this time, the helicopter had disappeared from view – within 30 seconds or so it had sunk into the dark blue water.

    Floating ice in Disko Bay, Greenland, close to the Davis Strait

    Then I took off my survival suit. Wearing nothing but my underwear, and shaking violently in the wind, I tipped as much water as I could out of the suit. Then I put it back on, squelchy wet and freezing cold. I did it up, lifting the ridiculous built-in hat over my head.

    The wind was absolutely killing me. I got down in a horizontal position and inflated the life raft. It was yellow and square. I tied one end of the raft to my leg and held on to the other with my hand, and hid underneath it, using it as a windbreaker.

    That was when I started to beat myself up. I was travelling with two trackers, a distress beacon and a satellite phone, but they had all gone down with the helicopter. “Why didn’t you dive in and get them?” I asked myself. “Sure, it would have been very unpleasant but you should have dived in.”

    Still, I felt confident that the alarm would be raised. I had several friends who I knew were monitoring my progress carefully and would see that the tracker on the helicopter had come to a standstill. But I also knew that the tracker’s final position may have been some distance from the place where I landed, and since it was not manually activated my friends had no way of knowing I was still alive.

    Data from Ananov’s flight tracker shows his attempt to circumnavigate the world

    I had a few packs of water, amounting to perhaps half a litre, and a small pack of protein bars – about 2,000 calories of food. I also had three flares, which had been packed inside the life raft.

    I got up and tried moving around a little, to keep my circulation going, but I found myself panting as though I were doing hard physical exercise. Throughout my time on the ice I did not stop shivering at all.

    One thing I was not particularly worried about was polar bears. My block of ice was adrift at sea, with just a few more lumps of ice nearby. Mainly it was water – water, water, water. And the wind.

    Then, about four hours after my forced landing, I was lying on my stomach in my makeshift tent, trying to retain heat and breathing as shallowly as I could through my nose, when I heard the sound of heavy breathing nearby and crunching snow. Footsteps. I peeked from under the bottom of the life raft and I saw him, a polar bear, sniffing the air and walking in my direction.

    Polar bears are amongst the world’s most powerful predators. Getty Images

    I had to make an instant decision. And I decided that since he had surprised me I would surprise him. So I jumped up and threw off the life raft. Boo! Then I rushed at him, arms upstretched, roaring.

    I was trying to show anger, and I really was angry – with myself, with the situation I was in and with this bear that had somehow found its way on to my lump of ice. How dare he come here and try to eat me!

    It must have looked ridiculous – like when you pretend to be a monster with children. But it worked. The bear turned and ran away. “Ok,” I thought, “he knows that I am the boss – now I have to build on that.” So I chased after him.

    Polar bears hunt for seals near the edges of sea ice. Arturo de Frias Marques

    We reached the edge of my piece of ice and he jumped nimbly to another. Well, I couldn’t do that, so I stood on the edge, my arms still in the air, my eyes black coals of rage, roaring. And I saw that the sea around me had been quite transformed, everything moved around by the wind. No longer was my ice lump isolated, a little island, but it now butted against others. Evidently, I was not safe from bears.

    The bear jogged on another 25m or so. Then he sat down on his backside and turned and looked at me mutely, like a dog. He wanted to know what I would do next – and so did I.

    Polar bears are not territorial and will avoid confrontation. Getty Images

    See the full article here .

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  • richardmitnick 8:48 pm on September 14, 2015 Permalink | Reply
    Tags: , BBC,   

    From BBC: “Implant ‘traps’ spreading cancer cells” 


    9 September 2015
    No Writer Credit

    Petri dish containing lots of the tiny implants.

    A small sponge-like implant that can mop up cancer cells as they move through the body has been developed by US researchers.

    So far tested in mice, it is hoped the device could act as an early warning system in patients, alerting doctors to cancer spread.

    The implant also seemed to stop rogue cancer cells reaching other areas where new tumours could grow.

    The findings appear in Nature Communications .

    Cancer Research UK said nine in 10 cancer deaths were caused by the disease spreading to other areas of the body.

    About 5mm (0.2in) in diameter and made of a “biomaterial” already approved for use in medical devices, the implant has so far been tested in mice with breast cancer.

    Experiments showed that implanting the device in either the abdominal fat or under the skin sucked up cancer cells that had started to circulate in the body.

    Metastasising breast cancer cell seen under electron microscope

    The implant mimicked a process where cells broken loose from a tumour were attracted to other areas in the body by immune cells, the researchers said.

    They found that these immune cells set up camp on the implant – a natural reaction to any foreign body – drawing the cancer cells in.

    Initially, the researchers “labelled” cancer cells so they would light up and be easily spotted.

    But they then moved on to a special imaging technique that can distinguish between cancerous and normal cells, and found they could detect cancer cells that had been caught in the implant.

    Reduce spread

    Unexpectedly, when they measured cancer cells that had spread in mice with and without the implant, they found that the device not only captured cancer cells, it reduced the numbers present at other sites.

    Researchers have long been looking for ways to detect the spread – or metastasis – of cancer at an early stage, but cancer cells that circulate in the bloodstream are rare and hard to detect.

    Study leader Prof Lonnie Shea, from the Department of Biomedical Engineering at the University of Michigan, said they were planning the first clinical trials in humans fairly soon.

    “We need to see if metastatic cells will show up in the implant in humans like they did in the mice, and also if it’s a safe procedure and that we can use the same imaging to detect cancer cells,” he said.

    He said they were continuing work in animals to see what happened to the overall outcome if cancer spread was detected at a very early stage – something which was not yet fully understood.

    Lucy Holmes, Cancer Research UK’s science information manager, said: “We urgently need new ways to stop cancer in its tracks.

    “So far this implant approach has only been tested in mice, but it’s encouraging to see these results, which could one day play a role in stopping cancer spread in patients.”

    See the full article here .

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  • richardmitnick 8:53 pm on August 11, 2015 Permalink | Reply
    Tags: , , BBC,   

    From BBC: “Lost in space? Nasa under pressure” 


    Aug 12, 2015
    Pallab Ghosh

    Nasa’s Pluto flyby was greeted with patriotic fervour at mission control in Laurel, Maryland. But amid the deserved celebration was there a hint of insecurity?

    The recent flyby of Pluto brought back memories of NASA at its best. But is the space agency’s effort to explore the Solar System with robotic spacecraft in trouble?

    Among NASA’s greatest achievements was sending astronauts to the Moon and returning them safely. An American flag was planted on the lunar surface. It marked a triumph for the US in the space race with the Soviet Union. But Neil Armstrong’s step on the Moon was a moment for the entire planet, briefly bringing together a divided and war-torn world.

    Forty-six years later, almost to the day, the Stars and Stripes was waved and there were chants of “USA!” at mission control as the New Horizons spacecraft flew past an unexplored world.

    America’s space agency and those working on the mission deserve to be congratulated on yet another great moment. No one should begrudge the scientists involved their celebration, but why such patriotic fervour this time?

    Coming just a year after Europe setting down a lander on a comet, India orbiting Mars and not long after China sending a rover to the Moon, could those who work for NASA be feeling a little insecure? If so, say observers, they may have good reason to be.

    Since the New Horizons spacecraft was launched, the US space agency has faced upheaval and a funding crisis.

    In 1969, the flag was planted on the lunar surface – but it was a moment that belonged to the entire world.

    And some of the agency’s robotic exploration projects have been mismanaged and over budget, leading the space agency to cut some of its planetary exploration missions.

    NASA’s James Webb telescope is the successor to its beloved and very successful Hubble Space Telescope and will be able to image some of the most distant objects in the Universe. It was supposed to have cost $1.6bn and to have been launched in 2011. The current projected cost is $8bn with a launch date of 2018. The scientific journal Nature called it “the telescope that ate astronomy”.

    NASA Webb Telescope

    NASA Hubble Telescope

    The most recent rover mission to Mars, Curiosity, landed successfully three years ago and has performed admirably. But the mission was around a billion over budget and three years late.

    NASA Mars Curiosity Rover

    These events were monitored by former NASA scientist Keith Cowing in his blog NASA Watch.

    “As upset as NASA proclaims to be when these overruns happen, they just go off and do another one. It is an ongoing chronic issue with NASA,” he told BBC News.

    “NASA’s financial management system is still a mess. After doing NASA Watch for 20 years it is almost like I have a key on my keyboard that I press and it says: ‘NASA doesn’t understand what things cost’.”

    A number of factors, including the US financial crisis, have caused the collapse of some collaborations between NASA and the European Space Agency (ESA) in recent years. These missions included a plan called EJSM/Laplace to explore the icy moons of Jupiter that might be hospitable to life and a joint Mars mission called ExoMars.

    In all these cases ESA either has or will go ahead on its own according to Prof Andrew Coates of the Mullard Space Science Laboratory which is part of University College London. Prof Coates is one of the principle investigators on ExoMars and a successor to EJSM/LaPlace the mission, called Juice, which is due for launch in 2022.


    “What this has done is that it has provided a fantastic opportunity for Europe to take a really leading role in space exploration, which it is doing with ExoMars and Juice,” he told BBC News.

    The Russian space programme has also experienced financial difficulties. Even so, it has plans to begin a series of robotic missions to the Moon with a view to developing a long term presence on the lunar surface and a proposal for a probe to Venus.

    Jupiter’s moon Europa is one of the places in our Solar System where life could currently exist. NASA first scrapped a mission to go there, but has given the go ahead to another at the behest of Congress

    China has had a series of robotic missions to the Moon and has plans for a new orbiting space station. It also has ambitions to send a probe to Mars.

    India too is now arriving at the top table of those exploring space with the arrival of an orbiter at Mars last year. It has plans for a follow-up. Meanwhile, Japan continues to have a strong scientific programme.

    India Mars Orbiter Mission
    Indian Mars Orbiter

    According to Prof John Logsdon, of George Washington University, rival space agencies are catching up fast.

    “NASA has had a series of successes, notably the landing of rovers on Mars, particularly Curiosity. But the planetary exploration programme has struggled for adequate funding. Its funding has been cut by between 10% and 15% and no flagship missions seem to have been put in place under Obama,” he told BBC News.

    NASA’s focus over the last decade has been on Mars. And although the Spirit and Opportunity missions and the Curiosity Rover have been scientific triumphs, Keith Cowing says other interesting worlds have been ignored.

    NASA Mars Spirit

    NASA Mars Opportunity Rover

    “There are a lot of people that think we have spent too much time on Mars and that Europa, Ganymede and Enceladus (moons of Jupiter and Saturn that could be hospitable to life) are worthy of our financial attention,” he says.

    NASA has reportedly been cajoled by Congress into revive plans to explore Europa as one of its next big missions.

    Two decades ago, NASA administrator Dan Goldin embarked on an effort to develop missions that were faster, better and cheaper – FBC in NASA jargon.

    Typically, a NASA programme can take between 10 and 15 years to develop from approval to launch. The Hubble Space Telescope, for example, took 20 years. Goldin’s aim was to have the turnaround for missions reduced to four years and their cost cut by a quarter.


    But questions were raised about FBC following high profile blunders in two low-cost missions to Mars: Mars Climate Orbiter and the Mars Polar Lander, both in 1999. There were no further FBC missions following these missions. But according to Richard Holdaway, former director of RAL Space, that was a mistake.

    “The cost overruns on the James Webb Space Telescope and the Curiosity mission became a significant problem. ‘Faster, better cheaper’ was the right approach, as we have seen with the success of the New Horizons mission,” he said.

    NASA New Horizons spacecraft
    New Horizons

    “But NASA didn’t implement it properly, with its full authority or stick to the criteria it set to cancel projects that were over-running.”

    Instead, NASA New Horizons seems to have lurched from bargain basement space missions back to gargantuan projects where costs have spun out of control – with the exception of the low-cost Discovery class and medium-cost New Frontiers class missions (of which New Horizons is one). According to Prof Coates, the European Space Agency has – generally speaking – a more balanced approach.

    “NASA learned the hard way that you can do two of those (faster, better, cheaper) at the same time but not three. Europe stayed the course on the larger missions such as Rosetta, ExoMars and Juice as well as small ones.”

    ESA Rosetta spacecraft

    ESA ExoMars

    So could it be time for NASA to rethink the “faster, better, cheaper” plan?

    “Dan Goldin was prophetic. But the way his idea was put into practice was flawed and inconsistent and insincere,” he says.

    “It’s like having the archetypical pictures of the little mammals running around as the dinosaurs are dying. There is always the seed of the next wave of doing things that emerges from the current way of doing things.”

    However, Prof Logsdon however believes that following a difficult period of transition, NASA is starting to get back on track.

    “Congress has forced it to develop a big new rocket which has constrained the funds available for ambitious new projects.

    “The James Webb is a big hiccup in the progress of robotic science missions – we are in this period of re-establishing our human space flight capability and getting ready to explore. Nasa is recovering and doing well in the missions that it is involved with. So I think the outlook is more positive than not.”

    See the full article here.

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  • richardmitnick 8:17 pm on August 10, 2015 Permalink | Reply
    Tags: , , BBC,   

    From BBC: “The Most Accurate Clocks in Space” 


    Aug 10, 2015
    Marcus Woo

    Fast-spinning pulsars can act as the universe’s timekeepers

    At first, Shri Kulkarni didn’t think it was a big deal. It was the middle of the night in September 1982, and he was at Arecibo Observatory in Puerto Rico, using the enormous radio dish to hunt for pulsars: the ultra-dense, rapidly spinning corpses of massive stars.

    Arecibo Observatory
    Arecibo Observatory

    He had just detected his first pulsar, and it was rotating really fast – once every 1.5 milliseconds – which was more than 20 times faster than any known at the time.

    Temp 1
    Credit: Detlev van Ravenswaay/SPL

    For Kulkarni, who was still a graduate student then, the rapid rotation didn’t mean much. It was just a fast pulsar, he thought. He called his project advisor, the late Don Backer, an astronomer at the University of California, Berkeley, US and delivered the news.

    “There was a long silence,” Kulkarni recalls. Probably because Backer knew this was big.

    He reminded Kulkarni what such a fast pulsar meant: this was an object spinning 641 times per second. “Many people thought that pulsars going at that speed would break apart,” says Kulkarni, now an astronomer at the California Institute of Technology in the US. Pulsars are as big as a city – about 20 km in diameter – and the assumption was that if it were rotating that fast, the centrifugal force would rip it to smithereens.

    Temp 2
    Neutron stars become extraordinarily dense (Credit: Jupe/Alamy)

    But now Kulkarni’s discovery upended that assumption. It changed not only his burgeoning career, but also an entire field. The pulsar, known as PSR B1937+21, became the first of a new class of remarkable objects called millisecond pulsars.

    Not only are they fast, but they also spin with such amazing regularity that they’re among the most accurate clocks in the universe. Using these celestial timekeepers, astronomers are answering questions about stars, matter – and even space and time itself – that would otherwise be impossible.

    Extreme objects

    Even ordinary pulsars are extraordinary. They’re some of the universe’s most extreme objects, the remains of stars between about eight and 20 times as massive as the sun. When such a star burns up its fuel and dies, it explodes in a supernova, blowing off its outer layers of gas.

    Temp 3
    Credit: Julian Baum/SPL

    What’s left is a core so dense that its electrons have fused with protons, forming a solid sphere of mostly neutrons. It’s become a neutron star. These objects squeeze between about 1.2 and 2 suns worth of mass into a ball no more than 20 km in diameter. Just a teaspoonful weighs a trillion kilograms – comparable to the mass of every person on Earth.

    Such density means the gravity on a neutron star’s surface is extremely strong – 100 billion times greater than Earth’s. If you tried standing on a neutron star (ignoring the million-degree temperatures, of course), you’d be squished, your atoms smeared across the surface. In fact, this overwhelming gravitational pull prevents the formation of any bumps greater than a few centimetres high, giving neutron stars some of the smoothest surfaces in space.

    And then there are the magnetic fields, the most powerful in the universe. Even the weakest is a hundred million times stronger than Earth’s – strong enough to warp the structure of an atom. At the poles, a neutron star’s magnetic field accelerates charged particles – positrons and electrons stripped off the surface by powerful electric fields – and blasts them into space in the form of jets. Those particles produce beams of radiation at radio frequencies, which eventually reach radio telescopes on Earth.

    It’s these beams that give pulsars their namesake. When a neutron star rotates rapidly, it swings these beams around like a lighthouse. From Earth, it appears as a steady, pulsating signal, sometimes as slow as once every 10 seconds.

    But they start out faster. They were cranking up the speed before they were pulsars, when they were stellar cores. As a star runs out of nuclear fuel, it can’t maintain the pressure needed to hold itself up, and the core contracts due to its own gravity.

    Like the way ice skaters spin faster when tucking their arms in, the core of a dying star rotates faster as it collapses. By the time the star dies and you’re left with a neutron star, it can be spinning as fast as 100 times a second. Over time, its rotating magnetic field loses energy, which slows the pulsar down.

    Which is why Kulkarni’s discovery of a pulsar going so much faster was so astounding. To whip it up to such speeds, astronomers realised, a pulsar must receive help from a companion star in orbit. As the companion exhausts its fuel, it swells – as all stars do eventually – and its outer layers start to spill onto the pulsar, forming a disk of hot gas spiraling inward like water circling a drain. The swirling disk spins up the pulsar.

    Temp 5
    Credit: Julian Baum/SPL

    The discovery of millisecond pulsars revitalized a moribund field, which started in 1967 when Jocelyn Bell discovered the first pulsar. The field’s landmark discovery came in 1974, when Russell Hulse and Joseph Taylor found two pulsars spiraling in toward each other. For that to happen, the energy of the pulsar’s orbits must be dissipating in the form of gravitational waves, ripples in the fabric of space-time.

    Their measurements were the clearest evidence yet that these waves exist, confirming a prediction of [Albert] Einstein’s theory of general relativity; they would later win the Nobel Prize in 1993. “That was the one highlight of the field,” Kulkarni says. It seemed all that was left to do was find more pulsars. “By 1982,” he says, “there was a sense that everything about pulsars had been discovered.”

    Cosmic laboratories

    That changed when Kulkarni found the first millisecond pulsar. Since then, astronomers have identified about 300 more. They estimate that the Milky Way Galaxy is home to 20,000 millisecond pulsars, and about an equal number of regular pulsars – a meagre number compared to the galaxy’s hundreds of billions of stars. PSR B1937+21 held the speed record until 2006, when Jason Hessels – who, like Kulkarni, was a graduate student at the time – discovered Terzan 5ad, a faint pulsar that spins 716 times per second.

    Temp 6
    Black holes may produce gravitational waves (Credit: Gl0ck/Alamy)

    With such high speeds and masses – lots of angular momentum, in physics-speak -millisecond pulsars are hard to slow down. That makes them incredibly consistent over a long period of time. When millisecond pulsars were first discovered, they rivaled the stability of atomic clocks. Today, atomic clocks have surpassed pulsars in accuracy. But if you were to compare them over a longer period of time – say, decades – pulsars can be just as good, says Hessels, who’s now at the University of Amsterdam in the Netherlands. Even after billions of years, a millisecond pulsar may slow down by only a few milliseconds. But because astronomers can precisely pin down its rate of deceleration, they can compensate and still use them as clocks.

    Millisecond pulsars are so stable that astronomers have measured their spin periods to an accuracy of one part in a million trillion (that’s 18 decimal places). They know when a pulse arrives on Earth to a precision of 100 nanoseconds. Because the pulses are so reliable, the tiniest deviations can reveal with great detail what’s going on in and around the pulsar – and in the space between the stars.

    In this space is dust and gas, called the interstellar medium, which obstructs and scatters a pulsar’s signals. By measuring the pulses’ delay, their intensity, and how sharp they are, astronomers can probe the properties of the interstellar medium, which plays a key role in how stars and galaxies form and evolve.

    Temp 7
    Credit: Claus Lunau/SPL

    Around the pulsar is the companion star that helped speed it up. The size of the star and how it evolves over time – for example, how changing magnetic activity can alter its shape – influences its orbit. Delays, modulations, or other variations in the pulses reveal what the companion star is like and how it interacts with the pulsar.

    Thanks to the precision of these pulses, astronomers can detect even the most subtle gravitational tugs. In 1992, astronomers discovered a planetary system orbiting a millisecond pulsar – the first planets found outside the solar system. The gravity of the planets were causing the pulsar to wobble ever so slightly, changing the arrival times of the pulses. In the case of Kulkarni’s pulsar, PSR B1937+21, these kinds of timing variations have recently suggested the presence of objects as small as asteroids.

    Detecting those pulses of radio waves – and, in some cases, X rays and gamma rays – is crucial because it’s often the only way for astronomers to observe and study these exotic pulsar systems. It’s also one of the only ways to study the weird structure and composition of the pulsar itself.

    Pulsars are essentially giant atomic nuclei. They can have a thin atmosphere not much more than 10 cm thick made of helium, hydrogen, and carbon, and an outer crust that’s mostly iron. As you go deeper, the matter becomes denser, full of neutrons (and some protons and electrons) in increasingly exotic forms, merging together to form strands and even sheets. But no one really knows what it’s like inside.

    Millisecond pulsars offer clues. The pulses allow scientists to precisely determine the pulsars’ orbits and thus their masses – crucial data that theorists need to constrain and devise new hypotheses. Nowhere in the universe can you find matter at such high densities and pressure. For physicists, pulsars are like laboratories for exploring such extremes – and maybe discovering entirely new types of matter.

    “It’s almost miraculous that there’s this type of star that’s so useful for testing areas of physics that would otherwise be inaccessible,” Hessels says.

    Testing Einstein

    Those areas include gravity itself. Einstein’s theory of general relativity describes gravity as bends and curves in the fabric of space-time, and so far, its predictions have been proven true again and again. But the theory may work differently in the enormous densities and strong gravity of pulsars—as strong as you can get without becoming a black hole. To find out whether that’s the case, researchers can look for discrepancies in the pulses.

    Temp 8
    Credit: Mark Garlick/SPL

    Recently, Hessels was part of a team that discovered a millisecond pulsar in a triple system with two white dwarfs—the remnants of stars not massive enough to form neutron stars. This rare configuration gives scientists a way to test one of the hallmarks of relativity: the equivalence principle.

    The principle says that gravity is the same for everyone and everything. Perhaps the most dramatic example is when astronaut Dave Scott dropped a hammer and a feather on the moon in 1971. Both hit the lunar surface at the same time, showing that the moon’s gravity pulled on both equally. Likewise, researchers want to see if the gravity of one of the white dwarfs pulls on the pulsar in the same way as the other white dwarf. They haven’t done the experiment yet, but the researchers say it could be the most accurate test ever of the equivalence principle.

    Of course, no one has found Einstein to be wrong just yet. One of the most successful confirmations of relativity was the Hulse-Taylor binary pulsar system, the big pre-millisecond-pulsar discovery that proved gravitational waves were real. Still, the evidence was indirect, based on measurements of orbits that allowed Hulse and Taylor to infer the existence of gravitational waves. To this day, a direct detection remains elusive.

    Temp 9
    A pulsar radiating light (Credit: Stocktrek Images Inc/Alamy)

    That’s despite the efforts of ground-based experiments such as LIGO, the Laser Interferometer Gravitational-Wave Observatory, which is designed to detect gravitational waves from colliding neutron stars or black holes. Its first observing run between 2002 and 2010 turned up nothing. After significant upgrades, it’s set to start up again in the fall of 2015.

    Caltech LIGO
    Caltech LIGO

    Meanwhile, an international effort has been racing to beat LIGO using – you guessed it – millisecond pulsars. “The idea is to use them as a galactic GPS,” says Hessels, who is part of the European contingent. When gravitational waves pass through Earth, the planet bobs like a buoy on the water. Those tiny motions alter the arrival times of the pulses.

    Over the last few years, astronomers have continued to refine their techniques, meticulously timing a few dozen of the best cosmic clocks known. And they hope to see something soon. “There’s a reasonable prospect of detecting gravitational waves in this way in the next five years or so,” says Ingrid Stairs, an astronomer at the University of British Columbia in Canada and member of the North American team.

    Temp 10
    The ultimate cosmic clock (Credit: Stocktrek Images Inc/Alamy)

    Still, Stairs thinks LIGO probably will beat them to it. But while LIGO is designed to detect waves from merging neutron stars and black holes several times as massive as the sun, the pulsar method is sensitive to collisions between supermassive black holes, which are millions to billions of times heftier than the sun. “It’s looking at a totally different source of gravitational waves,” she says. “Even if we’re later than LIGO, it doesn’t mean they’ve totally scooped us.”

    Regardless of who wins the race, the millisecond pulsar has been vital for understanding a range of cosmic phenomena. “It’s nature’s gift to us,” Kulkarni says. “It’s a precise, physical laboratory – but in the heavens.” It was a gift received more than three decades ago, and if it didn’t seem like a big deal then, it certainly does now.

    See the full article here.

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  • richardmitnick 7:15 am on August 7, 2015 Permalink | Reply
    Tags: , , BBC,   

    From BBC: “Trouble in orbit: the growing problem of space junk” 


    5 August 2015
    Dr Hugh Lewis, University of Southampton

    More than 5,000 launches since the start of the space age have left Earth orbit increasingly congested and contested.

    In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris. The problem also threatens crucial and costly satellites in orbit. So what is the scale of the space junk problem, and what can we do about it?

    Forty-five years ago the associate director of science at Nasa’s Marshall Space Flight Center, Ernst Stuhlinger, an original member of Wernher von Braun’s Operation Paperclip team, was asked by Sister Mary Jucunda, a Zambia-based nun, how he could suggest spending billions of dollars on spaceflight when many children were starving on Earth.

    Today, Stuhlinger’s response still provides a powerful justification for the costs associated with space research.

    “It is certainly not by accident that we begin to see the tremendous tasks waiting for us at a time when the young space age has provided us the first good look at our own planet,” he said.

    “Very fortunately though, the space age not only holds out a mirror in which we can see ourselves, it also provides us with the technologies, the challenge, the motivation, and even with the optimism to attack these tasks with confidence.”

    In the intervening years, the maturing space infrastructure has supported our new and ongoing efforts to tackle global health, hunger, poverty, education, disaster risk reduction, energy security and climate change.

    Indeed, we have made great use of Stuhlinger’s “mirror” to meet many of society’s biggest challenges.

    Sadly, the space environment has borne the brunt of our increasing reliance on satellites and our long-lived belief that “space is big”.

    More than 5,000 launches since the start of the space age, each carrying satellites for Earth observation, or communications, for example, have resulted in space becoming increasingly congested and contested. The issue has been examined for a BBC Horizon documentary on BBC Two.

    The US has a network of sensors, such as this 3.67m telescope in Hawaii, to track satellites and debris.

    Now, the US Space Surveillance Network is tracking tens of thousands of objects larger than a tennis ball orbiting above us, and we suspect that there are one hundred million objects larger than 1mm in the environment.

    Due to their enormous orbital speed (17,000 mph), each one of these objects carries with it the potential to damage or destroy the satellites that we now depend on.

    Red Conjunction

    Perhaps the most visible symptoms of the space junk problem are the regular collision avoidance manoeuvres being performed by the International Space Station (ISS), and the increasingly frequent and alarming need for its occupants to “shelter-in-place” when a piece of junk is detected too late for a manoeuvre.

    The systems on the ISS that provide vital life support are also responsible for its unique vulnerability to a debris impact – a pressurised module in a vacuum might behave like a balloon if punctured.

    The recent “red conjunction” (where a piece of debris comes close enough to pose a threat to the space station) involving a fragment from a Russian satellite on 17 July this year was yet another demonstration of the growing threat from space junk.

    Astronauts aboard the ISS shelter in the Soyuz capsule when a piece of junk is detected too late to manoeuvre

    Thanks to the hit film Gravity, and the Oscar-nominated performance of Sandra Bullock, we can now readily appreciate the anxiety that must be felt by the astronauts and cosmonauts aboard the International Space Station whenever they receive such a “red conjunction” call.

    In spite of these occurrences, the space station is actually orbiting at an altitude where the number of debris is relatively low.

    At higher altitudes the amount of space junk is substantially greater, but only robotic spacecraft are exposed there. Nevertheless, these satellites are some of the most valuable for understanding our planet. Due to this congestion, there is an increasing chance that the space junk population could become self-sustaining.

    That is, more junk could be created by collisions than is removed through the natural decay caused by atmospheric drag. Indeed, we already have some experience of this: in February 2009 two relatively small satellites collided over Siberia creating about 2,000 new fragments that could be tracked, with many still orbiting today and regularly passing close to other satellites.

    Space junk in numbers

    In 2007, a chunk of space debris punched this hole in the radiator panel of space shuttle Endeavour

    500,000 pieces of space debris between 1 and 10cm
    More than 21,000 pieces larger than 10cm
    More than 100 million pieces below 1cm
    Most orbital debris is within 2,000km of the Earth’s surface
    The greatest concentrations of debris are found at 750-800km
    Travel up to speeds of 28,163 km/h (17,500 mph)
    Only 7% of space junk is functional

    Sources: NASA, ESA

    The Kessler Syndrome

    Self-sustaining collision activity is something else that the film Gravity showed us. Dubbed the “Kessler Syndrome” after the Nasa scientist Don Kessler (now retired) who recognised and described this process with Burton Cour-Palais in 1978, such a scenario is a real – albeit often exaggerated – possibility.

    Concerns of an uncontrollable growth of the space junk population and the loss of key satellites that enable us to address our society’s problems have prompted scientists to look for ways to remove junk from space: If we can remove the problematic junk, then we can stall or even prevent the Kessler Syndrome.

    This is no easy task, however, requiring new technologies, potentially new laws and – crucially – financial investment. The European Space Agency (Esa) is taking the lead, working on a mission it calls “e.Deorbit” that has the objective of removing a large European satellite from space.

    The 2013 film Gravity, starring Sandra Bullock, depicts a collision cascade in orbit.

    The mission is ambitious; numerous technologies have been developed and assessed, including a solution based on a harpoon proposed by UK engineers from Airbus Defence and Space. It is also not without risk, but a successful outcome will surely show the space-faring world that a technical solution to the space junk problem exists, even if the political, legal and financial issues have yet to be solved.

    The e.Deorbit mission will face key hurdles in 2016: its systems requirements review and the Esa Ministerial Council meeting, where approval (and funding) to proceed with the mission will be debated.

    See the full article here.

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