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29th January 2015
Astronomers find exoplanet with gigantic ring system
Astronomers have discovered an exoplanet with a gigantic ring system, 200 times larger than that around Saturn.
An international team of astronomers has produced a new analysis of exoplanet data, showing how a ring system eclipses a star about 420 light years from Earth. Known as J1407, the star's age is estimated to be 16 million years, making it very young in stellar terms, with a mass 90% that of our Sun's. The accompanying planet is very large, at between 10 and 40 Jupiter masses, so it may in fact be a brown dwarf.
The planet's ring system – the first of its kind to be found outside our Solar System – is of gigantic size, much larger and heavier than Saturn's and described as "Saturn on steroids" by one astronomer. It is divided into at least 30 sections with a total diameter of 120 million km (75 million miles), equivalent to 80% of the distance between Earth and our Sun. Furthermore, gaps in the rings indicate that large satellites (“exomoons”) are present and may be up to 0.8 Earth masses.
“The details that we see in the light curve are incredible,” says Professor Matthew Kenworthy from the Leiden Observatory in the Netherlands, who led the study. “The eclipse lasted for several weeks, but you see rapid changes on time scales of tens of minutes as a result of fine structures in the rings. The star is much too far away to observe the rings directly, but we could make a detailed model based on the rapid brightness variations in the star light passing through the ring system. If we could replace Saturn’s rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon.”
Credit: Matthew Kenworthy, Leiden Observatory
“This planet is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn’s rings are today,” said Eric Mamajek, professor of physics and astronomy at the University of Rochester, who co-authored the paper. “You could think of it as kind of a super Saturn.”
“We see the rings blocking as much as 95 percent of the light of this young Sun-like star for days,” he adds. “So there is a lot of material there that could then form satellites.”
In their data, the astronomers found at least one clean gap within the ring structure: “One obvious explanation is that a satellite formed and carved out this gap,” says Kenworthy. “The mass of the satellite could be between that of Earth and Mars. The satellite would have an orbital period of approximately two years around J1407b.”
The researchers believe that the rings will become thinner in the next several million years and eventually disappear altogether as satellites coalesce from the material in the disks. They are encouraging amateur astronomers to help monitor this remarkable star system, to help detect the next eclipse of the rings and narrow down the possible range of values for the planet's orbital characteristics and mass.
“The planetary science community has theorised for decades that planets like Jupiter and Saturn would have had, at an early stage, disks around them that then led to the formation of satellites,” Mamajek explains. “However, until we discovered this object in 2012, no-one had seen such a ring system. This is the first snapshot of satellite formation on million-kilometre scales around a substellar object.”
The study has been accepted for publication in the Astrophysical Journal.
25th January 2015
Telomere extension in cultured human cells could lead to anti-aging therapies
Researchers at Stanford University have demonstrated a fast and reliable method of extending the length of telomeres – the protective caps at the end of chromosomes that play a key role in aging.
As illustrated above, telomeres are regions of DNA at the ends of chromosomes. Like the plastic tips at the end of shoelaces, they protect chromosomes from unravelling and deteriorating, or mixing with other chromosomes. Over time, however, telomeres will begin to erode and shorten. When telomeres become critically short, the cell enters an inactive state, stops dividing and dies. More and more cells reacting in this way causes tissue degeneration, which gradually results in aging and disease. A young human starts with telomeres around 8,000-10,000 nucleotides long, with each cell division reducing this length, so a person in their 80s will average 4,000-6,000 nucleotides.
Researchers at Stanford University School of Medicine, in a study published this week by the FASEB Journal, have found a way to extend the length of human telomeres by up to 900 nucleotides – equivalent to over 10 years of additional lifespan. This was achieved with human muscle and skin cells in a Petri dish using modified messenger RNA (mRNA) containing TERT, a vital part of the telomerase complex. Telomerase is an enzyme that occurs naturally and is known to prevent the shortening of telomeres. It is common in stem cells, but most other cell types have very low levels.
The new technique developed at Stanford was designed in a clever way that managed to optimise the available treatment time – maximising the effects of TERT by preventing an immune response being triggered in the cell, while minimising the danger of cancer that might result from TERT staying too long and causing too many divisions. A balance was achieved whereby TERT was able to remain temporarily for about 48 hours, long enough to increase telomere lengths by 10%, before dissipating harmlessly. During this time, cells divided many more times in the culture dish than did untreated cells: about 28 more times for the skin cells, and about three more times for the muscle cells.
"We were surprised and pleased that modified TERT mRNA worked, because TERT is highly regulated and must bind to another component of telomerase," says co-author John Ramunas, PhD, in a press release. "Previous attempts to deliver mRNA-encoding TERT caused an immune response against telomerase, which could be deleterious. In contrast, our technique is nonimmunogenic. Existing transient methods of extending telomeres act slowly, whereas our method acts over just a few days to reverse telomere shortening that occurs over more than a decade of normal aging. This suggests that a treatment using our method could be brief and infrequent."
"This new approach paves the way toward preventing or treating diseases of aging," says Helen Blau, PhD, a professor of microbiology and immunology at Stanford. "There are also highly debilitating genetic diseases associated with telomere shortening that could benefit from such a potential treatment.
"We're working to understand more about the differences among cell types, and how we can overcome those differences to allow this approach to be more universally useful. One day, it may be possible to target muscle stem cells in a patient with Duchenne muscular dystrophy, for example, to extend their telomeres. There are also implications for treating conditions of aging, such as diabetes and heart disease. This has really opened the doors to consider all types of potential uses of this therapy."
23rd January 2015
Long-term sequestration of carbon may be harder to achieve than previously thought
Long-term carbon sequestration is viewed as a way of mitigating climate change. It may be harder to achieve than previously thought, however, due to problems converting the gas to a solid state after injection underground, MIT reports.
Carbon sequestration promises to address human-made greenhouse-gas emissions by capturing carbon dioxide from the atmosphere and injecting it deep below the Earth’s surface, where it would permanently solidify into rock. The U.S. Environmental Protection Agency estimates that current sequestration technologies may eliminate up to 90 percent of carbon dioxide emissions from coal-fired power plants.
While such technologies may successfully remove greenhouse gases from the atmosphere, keeping them locked underground is another matter entirely. Researchers in the Department of Earth, Atmospheric and Planetary Sciences at MIT have found that once injected into the ground, less carbon dioxide is converted to rock than previously imagined. The team studied the chemical reactions between carbon dioxide and its surroundings once the gas is injected into the Earth – finding that as carbon dioxide works its way underground, only a small fraction turns to rock. The remaining gas stays in a more tenuous form.
“If it turns into rock, it’s stable and will remain there permanently,” says Yossi Cohen, a postdoctoral research associate. “However, if it stays in its gaseous or liquid phase, it remains mobile and it can possibly return back to the atmosphere.”
Current techniques aim to inject carbon dioxide into the subsurface some 7,000 feet below ground – a depth equivalent to five Empire State Buildings stacked end-to-end. At such depths, carbon dioxide is stored in deep-saline aquifers: large pockets of brine that can chemically react to solidify the carbon dioxide gas.
Credit: EPA
Cohen and Daniel Rothman, a professor of geophysics, sought to model the chemical reactions that occur after carbon dioxide is injected into a briny, rocky environment. When carbon dioxide is pumped into the ground, it rushes into open pockets within rock, displacing any existing fluid, such as brine. What remains are bubbles of carbon dioxide, along with carbon dioxide dissolved in water. The dissolved carbon dioxide takes the form of bicarbonate and carbonic acid, which create an acidic environment. To precipitate, or solidify into rock, carbon dioxide requires a basic environment, such as brine.
The researchers modelled the chemical reactions between two main regions:
• An acidic, low-pH region, with a high concentration of carbon dioxide
• A higher-pH region filled with brine, or salty water
As each carbonate species reacts differently when diffusing or flowing through water, the team characterised each reaction, then worked each one into a reactive diffusion model – a simulation of chemical reactions as carbon dioxide flows through a briny, rocky environment. When the team analysed the chemical reactions between regions rich in carbon dioxide and regions of brine, they found that the carbon dioxide solidifies – but only at the interface. The reaction essentially creates a solid wall at the point where carbon dioxide meets brine, keeping the bulk of the gas from reacting with the brine.
“This can basically close the channel, and no more material can move farther into the brine, because as soon as it touches the brine, it will become solid,” Cohen says. “The expectation was that most of the carbon dioxide would become solid mineral. Our work suggests that significantly less will precipitate.”
Cohen and Rothman point out that their theoretical predictions require experimental study to determine the magnitude of this effect.
“Experiments would help determine the kind of rock that would minimise this clogging phenomenon,” Cohen says. “There are many factors, such as the porosity and connectivity between pores in rocks, that will determine if and when carbon dioxide mineralises. Our study reveals new features of this problem that may help identify the optimal geologic formations for long-term sequestration.”
23rd January 2015
ATLAS humanoid robot gets an upgrade
This week, DARPA revealed upgrades to its bipedal humanoid ATLAS robot. The machine was redesigned for DARPA by Boston Dynamics, with the goal of improving power efficiency to better support battery operation. Approximately 75 percent of the robot was rebuilt; only the lower legs and feet were carried over from the original design. In the future, ATLAS could assist emergency services in search and rescue operations, performing tasks such as shutting off valves, opening doors and operating powered equipment in environments where humans could not survive.
In addition to improved power and the ability to function without a power cord, other upgrades to ATLAS include:
• Repositioned shoulders and arms allow for increased workspace in front of the robot and let the robot view its hands in motion, thus providing additional sensor feedback to the operator.
• New electrically actuated lower arms will increase strength and dexterity and improve force sensing.
• The addition of an extra degree of freedom in the wrist means the robot will be able to turn a door handle simply by rotating its wrist as opposed to moving its entire arm.
• Three onboard perception computers are used for perception and task planning, and a wireless router in the head enables untethered communication.
• Re-sized actuators in the hip, knee, and back give the robot greater strength.
• A wireless emergency stop allows for safe operation.
• As a result of its new pump, Atlas is much, much quieter than before.
The upgraded robot will be used by up to seven teams competing in the DARPA Robotics Challenge Finals, which take place on 5th and 6th June 2015 at Fairplex in Pomona, California. Admission to the event is free and open to the public. For more information see http://www.theroboticschallenge.org.
22nd January 2015
Tesco becomes first UK retailer to launch a Google Glass-enabled service
Tesco has become the first UK retailer to launch a customer Glass-enabled service with a basic version of its shopping app now available for users of the wearable device.
The Glassware has been developed by Tesco Labs, which experiments with disruptive technologies able to change the way customers shop. The Tesco Grocery Glassware lets you browse goods, view nutritional information and add items to your basket hands-free, via the voice search function or by scanning a product’s barcode using the headset’s built-in camera. In this, its first foray into providing services for wearable technology users, Tesco has intentionally kept the functionality of the app simple as it considers the consumer response to wearables and the likelihood of increased demand.
Pablo Coberly, Innovation Engineer at Tesco Labs comments, “At Tesco we want to ensure we have the means in place to allow customers to shop whenever, however they want which is why we’re testing the possibilities of customers topping up their online basket with Glass.”
The Tesco Grocery Glassware works alongside customers' Tesco.com grocery accounts, automatically adding products to their online basket for them to then review and order by computer, tablet or mobile. Pablo Coberly continues, “We don’t envisage Glass becoming the new platform for shopping as its functionality is different and more immediate. Instead, it compliments other devices and integrates shopping into everyday life because products can be ordered or added as and when customers realise they need replacing.”
As for the future of the Tesco Grocery Glassware, Tesco Labs says this will be driven by customer needs and demand. Pablo comments, “We’ve intentionally kept functionality very basic given the early stages of customer use of Glass. We’re keen to see how customers react to shopping with Glassware and welcome feedback or suggestions from customers using Glass.”
Last week, Google announced they would stop producing the Google Glass prototype, but remain committed to the product's development. In their eyes, Glass is ready to 'graduate' from Google Labs, the experimental phase of the project. The company will now focus on "future versions of Glass" with research and development handled by a different division to before.
Credit: von Tim.Reckmann (Eigenes Werk) [CC BY-SA 3.0]
22nd January 2015
Laying the foundations for 5G mobile
UK telecoms regulator, Ofcom, is calling on industry to help lay the foundations for the next generation of wireless communications.
So-called ‘5G’ mobile communications will use a very high frequency part of the spectrum above 6 GHz. This could support a variety of new uses including holographic projections and 3D medical imaging, with the potential to support very high demand users in busy areas, such as city centres. 5G mobile is expected to deliver extremely fast data speeds – perhaps 10 to 50 Gbit/s – compared with today’s average 4G download speed of 15 Mbit/s. 5G services are likely to use large blocks of spectrum to achieve these speeds, which are difficult to find at lower frequencies.
The timeframe for the launch of 5G services is uncertain, although commercial applications could emerge by 2020, subject to research and development and international agreements for aligning frequency bands. Ofcom says it is important to do the groundwork now, to understand how these frequencies might be used to serve citizens and consumers in the future. The regulator is therefore asking industry to help plan for the spectrum and bandwidth requirements of 5G.
The spectrum above 6 GHz currently supports various uses – from scientific research, to satellite broadcasting and weather monitoring. One of Ofcom’s core roles is to manage the limited supply of spectrum, taking into account the current and future demands to allow these different services to exist alongside each other.
Steve Unger, Ofcom's Acting Chief Executive: “We want the UK to be a leader in the next generation of wireless communications. Working with industry, we want to lay the foundations for the UK’s next generation of wireless communications.
“5G must deliver a further step change in the capacity of wireless networks – over and above that currently being delivered by 4G. No network has infinite capacity, but we need to move closer to the ideal of there always being sufficient capacity to meet consumers’ needs.”
Philip Marnick, Ofcom Spectrum Group Director, comments: “We want to explore how high frequency spectrum could potentially offer significant capacity for extremely fast 5G mobile data. This could pave the way for innovative new mobile services for UK consumers and businesses.”
These innovations, according to Ofcom, might include real-time holographic technologies, allowing relatives to virtually attend family gatherings. Or they could enable specialist surgeons to oversee hospital operations while located on the other side of the world, using 3D medical imaging.
Ofcom is seeking views on the use of spectrum above 6 GHz that might be suitable for future mobile communication services. The closing date for responses is 27th February 2015.
21st January 2015
Richest 1% will own more than all the rest by 2016
The combined wealth of the richest 1 per cent will overtake that of the other 99 per cent of people next year, unless the current trend of rising inequality is checked, Oxfam has warned ahead of the annual World Economic Forum meeting in Davos.
The international agency Oxfam, whose executive director Winnie Byanyima will co-chair the Davos event, warns that the explosion in inequality is holding back the fight against global poverty at a time when 1 in 9 people do not have enough to eat and more than a billion people still live on less than $1.25-a-day.
Byanyima will use her position at Davos to call for urgent action to stem this rising tide of inequality, starting with a crackdown on tax dodging by corporations, and to push for progress towards a global deal on climate change.
Wealth: Having it all and wanting more– a research paper published this week by Oxfam – shows that the richest 1 per cent have seen their share of global wealth increase from 44 per cent in 2009, to 48 per cent in 2014 and at this rate will surpass 50 per cent in 2016. Members of this global elite had an average wealth of $2.7m per adult in 2014.
Of the remaining 52 per cent of wealth, almost all (46 per cent) is owned by the rest of the richest fifth of the world's population. The other 80 per cent share just 5.5 per cent and had an average wealth of $3,851 per adult in 2014 – that's 1/700th of the average wealth of the 1 per cent.
"Do we really want to live in a world where the one per cent own more than the rest of us combined?" says Byanyima. "The scale of global inequality is quite simply staggering and despite the issues shooting up the global agenda, the gap between the richest and the rest is widening fast.
"In the past 12 months, we have seen world leaders from President Obama to Christine Lagarde talk more about tackling extreme inequality, but we are still waiting for many of them to walk the walk. It is time our leaders took on the powerful vested interests that stand in the way of a fairer and more prosperous world.
"Business as usual for the elite isn't a cost free option – failure to tackle inequality will set the fight against poverty back decades. The poor are hurt twice by rising inequality – they get a smaller share of the economic pie and because extreme inequality hurts growth, there is less pie to be shared around."
Lady Lynn Forester de Rothschild, CEO of EL Rothschild and chairman of the Coalition for Inclusive Capitalism, speaking at a joint Oxfam-University of Oxford event on inequality, called on business leaders meeting in Davos to play their part in tackling extreme inequality: "Oxfam's report is just the latest evidence that inequality has reached shocking extremes, and continues to grow. It is time for the global leaders of modern capitalism, in addition to our politicians, to work to change the system to make it more inclusive, more equitable and more sustainable.
"Extreme inequality isn't just a moral wrong. It undermines economic growth and threatens the private sector's bottom line. All those gathering at Davos who want a stable and prosperous world should make tackling inequality a top priority."
Oxfam made headlines at Davos in 2013, by highlighting that the 100 richest people on the planet had enough income to end poverty four times over, while in 2014, they revealed that the 85 richest individuals had the same wealth as the poorest 50 per cent (3.5 billion people). That number is now 80 – a dramatic fall from 388 people in 2010. The wealth of these richest 80 doubled in cash terms between 2009-14.
The international agency is calling on governments to adopt a seven point plan to tackle inequality:
- Clamp down on tax dodging by corporations and rich individuals
- Invest in universal, free public services such as health and education
- Share the tax burden fairly, shifting taxation from labour and consumption towards capital and wealth
- Introduce minimum wages and move towards a living wage for all workers
- Introduce equal pay legislation and promote economic policies to give women a fair deal
- Ensure adequate safety-nets for the poorest, including a minimum income guarantee
- Agree a global goal to tackle inequality.
This week's new research paper, which follows the October launch of Oxfam's global Even It Up campaign, shines a light on the way extreme wealth is passed down the generations and how elite groups mobilise their vast resources to ensure global rules are favourable towards their interests. Over a third of the 1,645 billionaires listed by Forbes inherited some or all of their riches.
Twenty per cent of billionaires have interests in the financial and insurance sectors – a group which saw their cash wealth increase by 11 per cent in the 12 months to March 2014. These sectors spent $550m lobbying policy makers in Washington and Brussels during 2013. The 2012 US election cycle alone saw the financial sector providing $571m in campaign contributions. Billionaires listed as having interests in the pharmaceutical and healthcare sectors saw their collective net worth increase by 47 per cent. During 2013, they spent more than $500m lobbying policy makers in Washington and Brussels.
Oxfam is concerned that the lobbying power of these sectors is a major barrier in the way of reforming the global tax system and of ensuring intellectual property rules do not lead to the world's poorest being denied life-saving medicines.
There is increasing evidence from the International Monetary Fund, among others, that extreme inequality is not just bad news for those at the bottom but also damages economic growth. In an interview with the Guardian, Byanyima says: "We want to bring a message from the people in the poorest countries in the world to the forum of the most powerful business and political leaders.
"The message is that rising inequality is dangerous. It’s bad for growth and it’s bad for governance. We see a concentration of wealth capturing power and leaving ordinary people voiceless and their interests uncared for.
"Extreme inequality is not just an accident or a natural rule of economics. It is the result of policies, and with different policies it can be reduced. I am optimistic that there will be change. A few years ago, the idea that extreme poverty was harmful was on the fringes of the economic and political debate. But having made the case, we now see an emerging consensus among business leaders, economic leaders, political leaders and even faith leaders."
20th January 2015
Dawn probe delivers new image of dwarf planet Ceres
NASA has released an animated view of the dwarf planet Ceres, taken by the approaching Dawn spacecraft.
As NASA's Dawn spacecraft closes in on Ceres, new images show the dwarf planet at 27 pixels across, about three times better than the calibration images taken in early December. These are the first in a series of images that will be taken for navigation purposes during the probe's approach.
Over the next several weeks, Dawn will deliver increasingly better and better images of the dwarf planet – leading up to the spacecraft's capture into orbit around Ceres on 6th March. These images will continue to improve as the spacecraft spirals closer to the surface during its 16-month study.
"We know so much about the solar system and yet so little about dwarf planet Ceres. Now, Dawn is ready to change that," said Marc Rayman, the chief engineer and mission director, based at NASA's Jet Propulsion Laboratory in California.
The best images of Ceres so far were taken by the Hubble Space Telescope in 2003-4. These most recent images from Dawn, taken 13th January 2015 – at 80% of Hubble resolution – are not quite as sharp. But Dawn's images will surpass Hubble's at the next imaging opportunity, at the end of January.
"Already, the [latest] images hint at first surface structures such as craters," said Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research, Germany.
Dawn's arrival will mark the first time a spacecraft has ever been to a dwarf planet. By far the largest body in the main asteroid belt, Ceres comprises approximately one-third of the mass of the whole belt, which lies between Mars and Jupiter. With an average diameter of 590 miles (950 km), it is the sixth largest body in the inner Solar System by mass and volume. Scientists believe it contains a vast amount of ice – a potentially major resource for human colonists in the future. Thanks to its small escape velocity and rich resources, Ceres could serve as a main base and transport hub for asteroid mining infrastructure while providing abundant water, fuel, and oxygen for ships passing through to more distant objects like the moons of Jupiter.
"The team is very excited to examine the surface of Ceres in never-before-seen detail," said Chris Russell, principal investigator for the mission, based at the University of California, Los Angeles. "We look forward to the surprises this mysterious world may bring."
15th January 2015
Fruit fly lifespan extended by up to 60%
Scientists have managed to considerably prolong the lifespan of flies by activating a gene which destroys unhealthy cells. The results could also open new possibilities in human anti-aging research.
Immortality has long been a dream for humans. In many ancient mythologies, for example, immortality is one of the traits that distinguishes humans from the gods. More recently, biological research has tried to prolong human lifespan using model organisms such as mice or flies. Researchers at the Institute of Cell Biology from the University of Bern in Switzerland, led by Eduardo Moreno, have developed a new method to extend the lifespan of flies based on improved selection of the best cells within the body. Their work appears today in the journal Cell.
"Our bodies are composed of several trillion cells," explains Moreno, "and during aging, those cells accumulate random errors due to stress or external insults, like UV-light from the sun." But those errors do not affect all cells at the same time and with the same intensity: "Because some cells are more affected than others, we reasoned that selecting the less affected cells – and eliminating the damaged ones – could be a good strategy to maintain tissue health and therefore delay aging and prolong lifespan."
A cellular quality control mechanism
To test their hypothesis, the researchers used Drosophila melanogaster flies. The first challenge was to find out which cells within the organs of Drosophila were healthier. Moreno's team identified a gene which was activated in less healthy cells. They called the gene ahuizotl (azot) after a mythological Aztec creature selectively targeting fishing boats to protect the fish population of lakes, because the function of the gene was also to selectively target less healthy or less fit cells to protect the integrity and health of the organs like the brain or the gut.
Credit: Cell / Elsevier Inc. / Marisa M. Merino et al.
(CC BY 3.0)
Normally, there are two copies of this gene in each cell. By inserting a third copy, the researchers were able to select better cells more efficiently. The consequences of this improved cell quality control mechanism were, according to Moreno, "very exciting": The flies appeared to maintain tissue health better, aged slower and had longer lifespans. "Our flies had median lifespans 50 to 60 percent longer than normal flies," says Christa Rhiner, one of the study authors. For comparison, two previous fruit fly studies we reported on showed increases of 28% and 30%, respectively.
Could azot also slow down the human aging process?
However, the potential of the results goes beyond creating Methuselah flies, the researchers say: Because the gene azot is conserved in humans, this opens the possibility that selecting the healthier or fitter cells within organs could in the future be used as an anti-aging mechanism. For example, it could prevent neuro- and tissue degeneration produced in our bodies over time.
11th January 2015
Neutron star hidden by warp in space-time
Astronomers have observed and measured a neutron star slipping out of view because of the warp in space-time its orbit creates. The star is expected to reappear in about 160 years.
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Illustration of one orbit of pulsar J1906 (on the right, with radio beams) around its companion (centred). In the space-time curvature caused by the companion (blue), the pulsar rotation axis slants throughout the orbit. For illustration the effect is exaggerated 1 million times here.
Videos and image credit: Joeri van Leeuwen / ASTRON / University of British Columbia (CC BY-SA 4.0) |
In an interstellar race against time, astronomers have measured the space-time warp in the gravity of a binary star system and determined the mass of a neutron star – just before it vanished from view.
The team, including University of British Columbia astronomer Ingrid Stairs, measured the masses of both stars in a binary pulsar system called J1906, which lies in a globular cluster known as Terzan 5, about 25,000 light years away. The pulsar spins and emits a lighthouse-like beam of radio waves every 144 milliseconds and orbits its companion star in under four hours.
"By precisely tracking the motion of the pulsar, we were able to measure the gravitational interaction between the two highly compact stars with extreme precision," says Stairs, a professor of physics and astronomy. "These two stars each weigh more than the Sun, but are still over 100 times closer together than the Earth is to the Sun. The resulting extreme gravity causes many remarkable effects."
According to general relativity, neutron stars wobble like a spinning top as they move through the gravitational well of a massive, nearby companion star. Orbit after orbit, the pulsar travels through a space-time that is curved, which impacts the star's spin axis.
"Through the effects of the immense mutual gravitational pull, the spin axis of the pulsar has now wobbled so much that the beams no longer hit Earth," explains Joeri van Leeuwen, an astrophysicist at the Netherlands Institute for Radio Astronomy, and University of Amsterdam, who led the study.
"The pulsar is now all but invisible to even the largest telescopes on Earth. This is the first time such a young pulsar has disappeared through precession. Fortunately this cosmic spinning top is expected to wobble back into view, but it might take as long as 160 years."
Only a handful of double neutron stars have had their mass calculated, with J1906 being the youngest. The results were published on Thursday in the Astrophysical Journal and presented at the American Astronomical Society meeting.
10th January 2015
Kepler telescope confirms 1000th exoplanet
NASA has announced the 1000th confirmed exoplanet discovered by the Kepler Space Telescope. Three of the newly confirmed exoplanets were found to orbit within habitable zones of their parent stars.
Launched by NASA in 2009, the Kepler space telescope became the first
instrument capable of finding Earth-sized and smaller extrasolar planets. Originally the mission was expected to last until 2016, but the second of four reaction wheels (used for aligning the telescope) failed in May 2013 – disabling the spacecraft and putting its future in doubt.
However, an alternative plan named K2 "Second Light" was presented for consideration in November 2013. This would involve Kepler operating in a reduced capability mode, but able to continue exoplanet discovery, using an ingenious "virtual" reaction wheel. K2 began in May 2014 and had scanned 35,000 stars by the end of the year. Its first confirmed exoplanet was detected in December 2014, a hot super-Earth 180 light-years away in the constellation Pisces.
Combining Kepler's original tally with hundreds of results from K2, a total of 4,175 potential candidates have now been observed, the 1,000th of which was officially verified this week, after a further eight new planets were added to the "confirmed" list. Three of the newly-validated worlds are located in their suns' habitable zone – the range of distances from the host star where liquid water might exist on the surface of an orbiting planet. Of the three, two are likely to be made of rock, like Earth.
Kepler-438b and Kepler-442b, pictured here in the top row, are less than 1.5 times the diameter of Earth. Kepler-438b lies around 475 light-years away and is 12% bigger than Earth, while Kepler-442b is 1,100 light-years away and 33% bigger than Earth. Both have relatively short orbits of 35 days and 112 days – similar to that of Mercury (88 days) in our own Solar System. However, their parent stars are smaller and cooler than Sol, making their habitable zones closer. The third, Kepler 440b, is less likely to be a rocky planet. On the bottom row are small habitable zone planets confirmed in previous years including Kepler-186f, Kepler-62e and Kepler-62f.
“Each result from the planet-hunting Kepler mission's treasure trove of data takes us another step closer to answering the question of whether we are alone in the Universe,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate at the agency’s headquarters in Washington. “The Kepler team and its science community continue to produce impressive results with the data from this venerable explorer.”
“With each new discovery of these small, possibly rocky worlds, our confidence strengthens in the determination of the true frequency of planets like Earth,” said co-author Doug Caldwell, SETI Institute Kepler scientist at NASA's Ames Research Centre in California. “The day is on the horizon when we’ll know how common temperate, rocky planets like Earth are.”
“Kepler collected data for four years – long enough that we can now tease out the Earth-size candidates in one Earth-year orbits,” said Fergal Mullally, another SETI Institute Kepler scientist. “We’re closer than we’ve ever been to finding Earth twins around other sun-like stars. These are the planets we’re looking for.”
Many of these exoplanets will be targeted in follow-up studies by the James Webb Space Telescope to characterise the atmospheres of distant worlds and search for signatures of life. Kepler has now discovered 1,000 exoplanets, but the James Webb and other future telescopes are expected to find even more.
If the current rate of discovery continues, then the number of confirmed exoplanets is predicted to surpass 13 million by the 2050s. This could reach into the hundreds of billions by the end of the century. In other words, pretty much every world in the Milky Way will have been catalogued. Assuming our telescopes also increase in magnification, we should also be able to observe them in close-up detail. We will then have to look at neighbouring galaxies for new planets.
8th January 2015
Progress towards an obesity pill
Researchers have developed a compound that causes the metabolism of mice to respond as if a meal has been eaten, so they burn fat to make room for new calories. Human trials could follow in the next few years.
Researchers from the Salk Institute for Biological Studies in California, USA, have developed a compound they describe as "an entirely new type" of pill that is able to prevent obesity in mice. Called fexaramine, it can stop weight gain, lower cholesterol and minimise inflammation.
Unlike most diet pills on the market, such as appetite suppressants or caffeine-based diet drugs, fexaramine won't dissolve into the blood. It remains within the intestines causing fewer side effects. It is so effective that researchers hope it can be fast-tracked for human trials within the next few years – perhaps by 2018, as predicted on our timeline.
“This pill is like an imaginary meal,” says Ronald Evans, director of Salk’s Gene Expression Laboratory and senior author of the study, which is published this week in Nature Medicine. “It sends out the same signals that normally happen when you eat a lot of food, so the body starts clearing out space to store it. But there are no calories and no change in appetite.”
Evans’ laboratory has spent nearly two decades studying the farensoid X receptor (FXR), a protein that plays a role in how the body releases bile acids from the liver, digests food and stores fats and sugars. The body turns on FXR at the beginning of a meal to prepare for an influx of food. FXR not only triggers the release of bile acids for digestion – but also changes blood sugar levels and causes the body to burn some fats in preparation for the incoming meal.
Pharmaceutical companies aiming to treat obesity, diabetes, liver disease and other metabolic conditions have developed systemic drugs that activate the FXR protein, turning on many pathways that it controls. But these drugs affect several organs and come with all kinds of side effects. Evans’ team has shown that switching on FXR only in the intestines – rather than the intestines, liver, kidneys and adrenal glands all at once – can have a very different outcome.
“The body’s response to a meal is like a relay race, and if you tell all the runners to go at the same time, you’ll never pass the baton,” says Evans. “We’ve learned how to trigger the first runner so that the rest of the events happen in a natural order.”
6th January 2015
2014 was hottest year on record globally
The Japan Meteorological Agency (JMA) has confirmed 2014 as the hottest year on record globally, surpassing the previous record of 1998.
The Japan Meteorological Agency (JMA) has confirmed 2014 as the hottest year on record globally, surpassing the previous record of 1998. What makes last year especially notable is that a new highest temperature occurred even without a significant El Niño, the phenomenon largely responsible for the enormous spike witnessed in 1998. Two other agencies – NASA, and the National Oceanic and Atmospheric Administration (NOAA) – are expected to make similar announcements as their data is released later this month. NASA and NOAA (who use different datasets to JMA) both currently have 2010 tied with 2005 as the hottest year.
While much of the USA was unusually cold during 2014, almost everywhere else on land saw either warmer than average or record high temperatures. Particularly warm regions included Australia, Europe and Siberia. The Met Office announced yesterday that 2014 was the UK's hottest year. In Australia, heatwaves reached higher than 49°C (120°F) at the start of last year, with records broken across the continent for the second year running.
The overwhelming majority (99.9%) of published, peer-reviewed studies agree that human emissions of heat-trapping greenhouse gases such as CO2 are the main cause of recent warming. As of today, no scientific institute of national or international standing disputes this. The U.S. military is now deeply concerned about the geopolitical consequences of a warmer world. Meanwhile, the insurance industry has warned of the mounting costs, with a tripling in the overall number of climate-related disasters that have resulted in losses since 1980. A rise of 0.8°C (1.4°F) may sound like a small amount, but on a planetary scale it's a huge quantity of energy: equivalent to four Hiroshima atomic bombs detonating every second.
As seen in the video below (released by NOAA last month), the atmospheric level of CO2 now stands at 400ppm and is forecast to hit 450ppm by 2030 – compared to around 280ppm prior to the Industrial Revolution. This rate of increase is unprecedented on a geologic timescale and is especially apparent in the chemistry of our oceans, which are now acidifying faster than at any time during the last 300 million years. World leaders are expected to agree a treaty on carbon emissions at the UN Climate Change Conference in Paris later this year – though judging by previous attempts, it is unlikely to be anything substantial.
5th January 2015
Whale genome may provide clues to 200-year lifespan
Scientists have mapped the bowhead whale genome and identified genes responsible for its 200-year lifespan, the longest of any mammal.
The bowhead whale is a 20 metre (65 ft) species of whale found in the waters of the Arctic and subarctic. It is believed to be the longest-lived mammal, with a recent study estimating they can live to at least 211 years of age, equivalent to a human born today reaching the year 2226. In a paper due for publication tomorrow in Cell Reports, a team from the Liverpool Centre for Genomics Research, UK – in collaboration with scientists in Alaska, Denmark, Ireland, Spain and South Korea – present the first complete bowhead whale genome and identify key differences compared to other mammals.
The researchers compared the bowhead's genes with those of a minke whale. The latter typically lives for only 30-50 years. As a result of their sequencing effort, they found that bowhead whales have unique mutations in two genes. These are the ERCC1 gene – which is believed to repair DNA, increase cancer resistance and slow aging – and the PCNA gene, which is also linked to DNA repair.
"Our understanding of species' differences in longevity is very poor – and thus our findings provide novel candidate genes for future studies," says the senior author, Dr. João Pedro de Magalhães, of the University of Liverpool, UK. "My view is that species evolved different 'tricks' to have a longer lifespan, and by discovering the 'tricks' used by the bowhead, we may be able to apply those findings to humans in order to fight age-related diseases."
The fact that large whales, with over 1,000 times more cells than humans, do not seem to have an increased risk of cancer suggests the existence of natural mechanisms that can suppress cancer more effectively than those of other animals. Dr. Magalhães now hopes to begin a project that will insert bowhead whales' genes into mice to observe the effects on health. If successful, human trials could follow, using drugs to activate the genes already inside the body, or by inserting the bowhead's genes into human cells before inserting them back into people.
The researchers also note that because the bowhead's genome is the first among large whales to be sequenced, the new information may help reveal physiological adaptations related to size. For example, whale cells have a much lower metabolic rate than those of smaller mammals, and the researchers found changes in one specific gene involved in thermoregulation (UCP1) that may be related to metabolic differences in whale cells.
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