25 Oct 2016

Latest dark matter searches leave scientists empty-handed

101816_EC_darkmatter_inlineIn initial searches, proponents of WIMPs expected that the particles would be easy to find. “It was thought to be like, ‘OK, we’ll run the detector for five minutes, discover dark matter, and we’re all done,’” says physicist Matthew Szydagis of the University at Albany in New York, a member of LUX. That has turned into decades of hard work. As WIMPs keep failing to turn up, some scientists are beginning to become less enamoured with the particles and are considering other possibilities more closely.

One alternative dark matter contender now attracting more attention is the axion. This particle was originally proposed decades ago as part of the solution to a particle physics quandary known as the strong CP problem — the question of why the strong nuclear force, which holds particles together inside the nucleus, treats matter and antimatter  equally. If dark matter consists of axions, the particle could therefore solve two problems at once.

Axions are small fry as dark matter goes — they can be as tiny as a millionth of a billionth the mass of a WIMP. The particles interact so feebly that they are extremely difficult to detect. If axions are dark matter, “you’re sitting in an enormous, dense sea of axions and you don’t even notice them,” says physicist Leslie Rosenberg of the University of Washington in Seattle, the leader of the Axion Dark Matter eXperiment. After a recent upgrade to the experiment, ADMX scientists are searching for dark matter axions using a magnetic field and special equipment to coax the particles to convert into photons, which can then be detected.

Although WIMPs and axions remain the front-runners, scientists are beginning to move beyond these two possibilities. In between the featherweight axions and hulking WIMPs lies a broad range of masses that hasn’t been well explored. Scientists’ favorite theories don’t predict dark matter particles with such intermediate masses, says theoretical physicist Kathryn Zurek of Lawrence Berkeley National Laboratory in California, but that doesn’t mean that dark matter couldn’t be found there. Zurek advocates a diverse search over a broad range of masses, instead of focusing on one particular theory. “Dark matter direct detection is not one-size-fits-all,” she says.

In two papers published in Physical Review Letters on January 7 and September 14,  Zurek and colleagues proposed using superconductors — materials that allow electricity to flow without resistance — and superfluid's, which allow fluids to flow without friction, to detect light dark matter particles. “We are trying to broaden as much as possible the tools to search for dark matter,” says Zurek. Likewise, scientists with the upcoming Super Cryogenic Dark Matter Search SNOLAB experiment, to be located in an underground lab in Sudbury, Canada, will use detectors made of germanium and silicon to search for dark matter with smaller masses than the xenon experiments can.

101816_EC_darkmatter_inline2Scientists have not given up on xenon WIMP experiments. Soon some of those experiments will be scaling up — going from hundreds of kilograms of liquid xenon to tons — to improve their chances of catching a dark matter particle on the fly. The next version of XENON100, the XENON1T experiment (pronounced “XENON one ton”) is nearly ready to begin taking data. LUX’s next generation experiment, known as LUX-ZEPLIN or LZ, is scheduled to begin in 2020. PandaX-II scientists are also planning a sequel. Physicists are still optimistic that these detectors will finally find the elusive particles. “Maybe we will have some opportunity to see something nobody has seen,” says Xiangdong Ji of Shanghai Jiao Tong University, the leader of PandaX-II. “That’s what’s so exciting.”

In the sea of no detections of dark matter, there is one glaring exception. For years, scientists with the DAMA/LIBRA experiment at Gran Sasso have claimed to see signs of dark matter, using crystals of sodium iodide. But other experiments have found no signs of DAMA’s dark matter. Many scientists believe that DAMA has been debunked. “I don't know what generates the weird signal that DAMA sees,” says Hooper. “That being said, I don't think it's likely that it’s dark matter.”

But other experiments have not used the same technology as DAMA, says theoretical astrophysicist Katherine Freese of the University of Michigan in Ann Arbor. “There is no alternative explanation that anybody can think of, so that is why it is actually still very interesting.” Three upcoming experiments should soon close the door on the mystery, by searching for dark matter using sodium iodide, as DAMA does: the ANAIS experiment in the Canfranc Underground Laboratory in Spain, the COSINE-100 experiment at YangYang Underground Laboratory in South Korea, and the SABRE experiment, planned for the Stawell Underground Physics Laboratory in Australia.

Scientists’ efforts could still end up being for naught; dark matter may not be directly detectable at all. “It’s possible that gravity is the only lens with which we can view dark matter,” says Szydagis. Dark matter could interact only via gravity, not via the weak force or any other force. Or it could live in its own “hidden sector” of particles that interact among themselves, but mostly shun normal matter.

Even if no particles are detected anytime soon, most scientists remain convinced that an unseen form of matter exists. No alternative theory can explain all of scientists’ cosmological observations. “The human being is not going to give up for a long, long time to try to search for dark matter, because it’s such a big problem for us,” says Ji

Powerful New Camera Will Observe How First Stars Formed


A group of astronomers at Arizona State University is seeking answers to such questions as part of an international experiment that has been awarded more than $6 million in funding from the National Science Foundation to help build a uniquely sensitive camera, called TolTEC, to probe these mysteries.

"Half the light from stars in the universe is absorbed by clouds of interstellar dust and then re-radiated at long wavelengths invisible to the human eye," said Philip Mauskopf, of Arizona State University's School of Earth and Space Exploration (SESE). "Astronomical observations at these wavelengths can let us see into the cores of stellar nurseries where new stars are forming."

Mauskopf, a professor in SESE, is the leader of the ASU team that will design and construct the optics for the new camera. The team will also develop the electronics for producing images from the instrument's superconducting detectors.

The new camera will be attached to a giant telescope in Mexico. On top of the 15,000-foot Sierra Negra in the state of Puebla sits the Large Millimeter Telescope (pictured above), with a 50-meter (164-foot) diameter main mirror.

It is the largest telescope in the world designed to operate at a wavelength of 1 millimeter, ideal for making detailed study of the dusty universe. The construction of this telescope, with contributions from the University of Massachusetts, has been the biggest scientific project in the history of Mexico.

Over the next three years, an international consortium, led by UMass, will build the golf-cart-size TolTEC cryogenic camera for the Large Millimeter Telescope. It will survey the universe, imaging radiation from dust at millimeter-wavelengths across large areas of sky.

The astronomers expect these images will reveal millions of previously unknown galaxies that are invisible to standard optical telescopes due to their large dust content.

Watch again my program ‘In Search of the First Stars”

"Over the last decade, smaller cameras and telescopes have discovered thousands of these galaxies," Mauskopf said. "This new project will allow a complete census of dusty galaxies in the universe and enable us to truly begin to understand their properties."

Because of interstellar dust, star-forming regions such as the Eagle Nebula (M16) show relatively little when observed in visible light. This infrared view by the Herschel Space Observatory shows star formation activity inside the giant cloud of dusty gas. But the new TolTEC camera (with ASU optics and electronics) will produce views of stellar nurseries like this with finer detail.

In addition to Mauskopf, the ASU team includes postdoctoral scholar Sean Bryan, electrical engineer Hamdi Mani, mechanical engineer Matt Underhill as well as graduate student and NASA Earth and Space Science fellow Sam Gordon and Barrett Honors College student Rhys Kelso.

"To get the best images, we have to supercool the optics and the superconducting detectors," Mauskopf said. "While developing this kind of superconducting technology can be difficult, the detectors and readout electronics we are using for TolTEC are very similar to ones we have already developed for use on balloon-borne telescopes at shorter wavelengths."

Once the TolTEC camera is completed, it will be mounted on the Large Millimeter Telescope and begin a two-year program of three large sky surveys covering hundreds of square degrees. These surveys will target regions where there are known dust clouds in our own galaxy. They will also target regions where there is relatively little local dust so that more distant objects are visible for comparison with deep optical images containing large numbers of galaxies.

Observations that require today’s telescopes five years to complete will be done in a little more than a week with TolTEC.

"It’s hard to grasp the increased capabilities of the new instrument," said Grant Wilson of UMass, principal investigator for TolTEC. "The combination of the new camera and the LMT requires a new outlook on what types of investigations are possible."

9557065177_0199fb6c28_h_0The details of the TolTEC surveys will be worked out in consultation with the international astronomical community through a series of workshops led by members of the TolTEC scientific advisory board. Data from the surveys will be made public as quickly as possible to allow the maximum scientific return.

The data from TolTEC will enable cosmologists, such as SESE's Evan Scannapieco, to trace the mysterious mechanism that is shutting off star formation in giant galaxies. It will also help astronomers including SESE's Judd Bowman, Rogier Windhorst, James Rhoads and Sangeeta Malhotra, who are using other methods to directly observe the oldest and most distant galaxies responsible for the re-ionization of the hydrogen gas in the early universe.

"Designing and building this camera will be a wonderful hands-on opportunity for SESE students and researchers," Mauskopf said. "And the end result will be a powerful new tool for studying the universe."

Other partners in TolTEC include the National Institute of Standards and Technology, Northwestern University, the University of Michigan, Cardiff University (UK), and the National Institute of Astrophysics, Optics and Electronics in Mexico.

Top photo: Researchers and students at the School of Earth and Space Exploration will design and build the optics and electronics for a new, highly sensitive camera, dubbed TolTEC, for the Large Millimeter Telescope in Mexico. The camera will enable astronomers to observe deep inside galactic clouds of obscuring dust in regions of space where stars are being born. It will also help cosmologists trace the evolution of galaxies in the early universe. Image by LMT/James Lowenthal

24 Oct 2016

Autumn Skies

Running time : 30 minutes  Presented by Richard Pearson FRAS.
October 2016

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The Night Sky: November 2016


Northern hemisphere observers can once again use Orion, which rises in mid-evening though it is not at its very best until after midnight. Much of the Hunter's retinue is on view - Capella, Aldebaran, the Twins - though Sirius does not appear until later. Ursa Major is still low in the north, and Arcturus has disappeared; the W of Cassiopeia is almost at the zenith. We are losing the Summer Triang...le as a dominant feature, and Altair sets before midnight. Pegasus is still there, with Andromeda and Perseus; Cetus and Eridanus sprawl across the southern aspect, but we have to ail intents and purposes lost Fomalhaut in the evening twilight. This is a good time of the year to track the Milky Way, from Cygnus right across the zenith and down to Gemini in the east.

My new program: 'The Clouds of Magellan' will be available to watch soon :)

From southern countries, this is an ideal time to study the Clouds of Magellan, which, with the Southern Birds, are almost overhead. Orion is with us once more, and Sirius shines brilliantly in the east; Canopus is high up, and it is interesting to compare the two. Sirius looks much the brighter, and one has to use one's imagination to realize that compared with Canopus it is puny; according to the figures in the Cambridge catalogue, it would take more than 7500 stars of the luminosity of Sirius to equal the power of Canopus. Achernar is high, and the Cross still rather low in the south. The Square of Pegasus is setting in the north-east, but Andromeda remains visible low over the horizon. Cetus is well displayed, and we can see the whole of the River Eridanus, from the area of Orion through to the far south.


234 stars from a sample of 2.5 million show odd pulsing signal which could indicate alien life

hs-1996-22-a-web_printA new study by astronomers from Laval University in Canada identified 234 stars out of a sample of 2.5 million which display odd pulsing signal. They believe the pulsing is similar to an intelligent alien race trying to make a contact.

Collective Evolution reports that Ermanno Borra and Eric Trottier from the university studied the samples from 2.5 million stars that were part of the Sloan Digital Sky Survey project. A previous study by Borra led them to conclude the signals recorded could be from aliens based on his envision of the shape of an extra-terrestrial intelligence (ETI) signal.

The project created the most detailed 3D maps of the universe with deep multi-colour images of one-third of the sky and spectra for over 3 million astronomical objects.

The two astronomers used a Fourier transform analysis and found on 234 stars signals in the F2 to K1 range. The signals could not be caused by instrumental or data analysis effects since it is present in only a very small fraction of stars within a narrow spectral range. Among the other possibilities that Borra and Trottier considered were rotational transitions in molecules, rapid pulsations, Fourier transform of spectral lines and signals generated by ETI.

But they acknowledge their finding is not the discovery needed to confirm humans are not alone in the universe. More work is needed to even suggest that theory.

The Breakthrough Listen Initiative, a scientific and technological explorations programme, with Stephen Hawking and Facebook CEO Mark Zuckerberg on its board, plans to expand on the study’s findings since more proof is needed from an outside source to prove the claims of the astronomers are true.

The initiative adds, “Internationally agreed-upon protocols for searches for evidence of advanced life beyond Earth (SETI) require candidates to be confirmed by independent groups using their own telescopes, and for all natural explanations to be exhausted before invoking extra-terrestrial agents as an explanation.”

23 Oct 2016

The universe is expanding at an accelerating rate – or is it?


As a new bright nova was today discovered in the constellation of Lepus (The Hare): Mag 16:  RA 05h 31m 41.25s DEC -14d 11m 59.0s., [ Shown above ] Nova have become the new tool to help work out if our Universe is expanding --- Maybe it isn’t, and there is NO Dark Matter either!

By Stuart Gillespie

Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace.

Their conclusions were based on analysis of Type Ia supernovae – the spectacular thermonuclear explosions of dying stars – picked up by the Hubble space telescope and large ground-based telescopes. It led to the widespread acceptance of the idea that the universe is dominated by a mysterious substance named 'dark energy' that drives this accelerating expansion.

Now, a team of scientists led by Professor Subir Sarkar of Oxford University's Department of Physics has cast doubt on this standard cosmological concept. Making use of a vastly increased data set – a catalogue of 740 Type Ia supernovae, more than ten times the original sample size – the researchers have found that the evidence for acceleration may be flimsier than previously thought, with the data being consistent with a constant rate of expansion.

The study is published in the Nature journal Scientific Reports.

Professor Sarkar, who also holds a position at the Niels Bohr Institute in Copenhagen, said: 'The discovery of the accelerating expansion of the universe won the Nobel Prize, the Gruber Cosmology Prize, and the Breakthrough Prize in Fundamental Physics. It led to the widespread acceptance of the idea that the universe is dominated by "dark energy" that behaves like a cosmological constant – this is now the "standard model" of cosmology.

'However, there now exists a much bigger database of supernovae on which to perform rigorous and detailed statistical analyses. We analysed the latest catalogue of 740 Type Ia supernovae – over ten times bigger than the original samples on which the discovery claim was based – and found that the evidence for accelerated expansion is, at most, what physicists call "3 sigma". This is far short of the 5 sigma standard required to claim a discovery of fundamental significance.


'An analogous example in this context would be the recent suggestion for a new particle weighing 750 GeV based on data from the Large Hadron Collider at CERN. It initially had even higher significance – 3.9 and 3.4 sigma in December last year – and stimulated over 500 theoretical papers. However, it was announced in August that new data shows that the significance has dropped to less than 1 sigma. It was just a statistical fluctuation, and there is no such particle.'

There is other data available that appears to support the idea of an accelerating universe, such as information on the cosmic microwave background – the faint afterglow of the Big Bang – from the Planck satellite. However, Professor Sarkar said: 'All of these tests are indirect, carried out in the framework of an assumed model, and the cosmic microwave background is not directly affected by dark energy. Actually, there is indeed a subtle effect, the late-integrated Sachs-Wolfe effect, but this has not been convincingly detected.

'So it is quite possible that we are being misled and that the apparent manifestation of dark energy is a consequence of analysing the data in an oversimplified theoretical model – one that was in fact constructed in the 1930s, long before there was any real data. A more sophisticated theoretical framework accounting for the observation that the universe is not exactly homogeneous and that its matter content may not behave as an ideal gas – two key assumptions of standard cosmology – may well be able to account for all observations without requiring dark energy. Indeed, vacuum energy is something of which we have absolutely no understanding in fundamental theory.'

Professor Sarkar added: 'Naturally, a lot of work will be necessary to convince the physics community of this, but our work serves to demonstrate that a key pillar of the standard cosmological model is rather shaky. Hopefully this will motivate better analyses of cosmological data, as well as inspiring theorists to investigate more nuanced cosmological models. Significant progress will be made when the European Extremely Large Telescope makes observations with an ultrasensitive "laser comb" to directly measure over a ten to 15-year period whether the expansion rate is indeed accelerating.'

Tracking waves from sunspots gives new solar insight

161020104613_1_900x600While it often seems unvarying from our viewpoint on Earth, the sun is constantly changing. Material courses through not only the star itself, but throughout its expansive atmosphere. Understanding the dance of this charged gas is a key part of better understanding our sun -- how it heats up its atmosphere, how it creates a steady flow of solar wind streaming outward in all directions, and how magnetic fields twist and turn to create regions that can explode in giant eruptions. Now, for the first time, researchers have tracked a particular kind of solar wave as it swept upward from the sun's surface through its atmosphere, adding to our understanding of how solar material travels throughout the sun.

Tracking solar waves like this provides a novel tool for scientists to study the atmosphere of the sun. The imagery of the journey also confirms existing ideas, helping to nail down the existence of a mechanism that moves energy -- and therefore heat -- into the sun's mysteriously-hot upper atmosphere, called the corona. A study on these results was published Oct. 11, 2016, in The Astrophysical Journal Letters.

"We see certain kinds of solar seismic waves channeling upwards into the lower atmosphere, called the chromosphere, and from there, into the corona," said Junwei Zhao, a solar scientist at Stanford University in Stanford, California, and lead author on the study. "This research gives us a new viewpoint to look at waves that can contribute to the energy of the atmosphere."

The study makes use of the wealth of data captured by NASA's Solar Dynamics Observatory, NASA's Interface Region Imaging Spectrograph, and the Big Bear Solar Observatory in Big Bear Lake, California. Together, these observatories watch the sun in 16 wavelengths of light that show the sun's surface and lower atmosphere. SDO alone captures 11 of these.

"SDO takes images of the sun in many different wavelengths at a high time resolution," said Dean Pesnell, SDO project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "That lets you see the frequencies of these waves -- if you didn't have such rapid-fire images, you'd lose track of the waves from one image to the next."

Though scientists have long suspected that the waves they spot in the sun's surface, called the photosphere, are linked to those seen in the lowest reaches of the sun's atmosphere, called the chromosphere, this new analysis is the first time that scientists have managed to actually watch the wave travel up through the various layers into the sun's atmosphere.

When material is heated to high temperatures, it releases energy in the form of light. The type, or wavelength, of that light is determined by what the material is, as well as its temperature. That means different wavelengths from the sun can be mapped to different temperatures of solar material. Since we know how the sun's temperature changes throughout the layers of its atmosphere, we can then order these wavelengths according to their height above the surface -- and essentially watch solar waves as they travel upwards.

The implications of this study are twofold -- first, this technique for watching the waves itself gives scientists a new tool to understand the sun's lower atmosphere.

"Watching the waves move upwards tells us a lot about the properties of the atmosphere above sunspots -- like temperature, pressure, and density," said Ruizhu Chen, a graduate student scientist at Stanford who is an author on the study. "More importantly, we can figure out the magnetic field strength and direction."

The effect of the magnetic field on these waves is pronounced. Instead of traveling straight upwards through the sun, the waves veer off, taking a curved path through the atmosphere.

"The magnetic field is acting like railroad tracks, guiding the waves as they move up through the atmosphere," said Pesnell, who was not involved in this study.

The second implication of this new research is for a long-standing question in solar physics -- the coronal heating problem.

The sun produces energy by fusing hydrogen at its core, so the simplest models suggest that each layer of the sun should be cooler as you move outward. However, the sun's atmosphere, called the corona, is about a hundred times hotter than the region below -- counter to what you would expect.

No one has as-yet been able to definitively pinpoint the source of all the extra heat in the corona, but these waves may play a small role.

"When a wave travels upwards, a number of different things can happen," said Zhao. "Some may reflect back downwards, or contribute to heating -- but by how much, we don't yet know."

NASA Goddard built, operates and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington. Lockheed Martin designed the IRIS observatory and manages the mission for NASA. The Big Bear Solar Observatory is operated by the New Jersey Institute of Technology in Newark, New Jersey.

22 Oct 2016

Astronomers find oldest known planetary disk


A group of citizen scientists and professional astronomers, including Carnegie’s Jonathan Gagné, joined forces to discover an unusual hunting ground for exoplanets. They found a star surrounded by the oldest known circumstellar disk—a primordial ring of gas and dust that orbits around a young star and from which planets can form as the material collides and aggregates.

Led by Steven Silverberg of University of Oklahoma, the team described a newly identified red dwarf star with a warm circumstellar disk, of the kind associated with young planetary systems.  Circumstellar disks around red dwarfs like this one are rare to begin with, but this star, called AWI0005x3s, appears to have sustained its disk for an exceptionally long time. The findings are published by The Astrophysical Journal Letters.

"Most disks of this kind fade away in less than 30 million years," said Silverberg. "This particular red dwarf is a candidate member of the Carina stellar association, which would make it around 45 million years old [like the rest of the stars in that group]. It's the oldest red dwarf system with a disk we've seen in one of these associations."

The discovery relied on citizen scientists from Disk Detective, a project led by NASA/GSFC's Dr. Marc Kuchner that’s designed to find new circumstellar disks. At the project’s website, Disk Detective.org, users make classifications by viewing ten-second videos of data from NASA surveys, including the Wide-field Infrared Survey Explorer mission (WISE) and Two-Micron All Sky Survey (2MASS) projects. Since the launch of the website in January 2014, roughly 30,000 citizen scientists have participated in this process, performing roughly 2 million classifications of celestial objects.

"Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object," Kuchner said. "The WISE mission alone found 747 million [warm infrared] objects, of which we expect a few thousand to be circumstellar disks.”

“Unravelling the mysteries of our universe, while contributing to the advancement of astronomy, is without a doubt a dream come true,” says Hugo Durantini Luca from Argentina, one of eight citizen scientist co-authors. 

Determining the age of a star can be tricky or impossible. But the Carina association, where this red dwarf was found, is a group of stars whose motions through the Galaxy indicate that they were all born at roughly the same time in the same stellar nursery.

Carnegie’s Gagné devised a test that showed this newly found red dwarf and its disk are likely part of the Carina association, which was key to revealing its surprising age.

“It is surprising to see a circumstellar disk around a star that may be 45 million years old, because we normally expect these disks to dissipate within a few million years,” Gagné explained. “More observations will be needed to determine whether the star is really as old as we suspect, and if it turns out to be, it will certainly become a benchmark system to understand the lifetime of disks."

Knowing that this star and its disk are so old may help scientists understand why M dwarf disks appear to be so rare.

This star and its disk are interesting for another reason: the possibility that it could host extrasolar planets. Most of the extrasolar planets that have been found by telescopes have been located in disks similar to the one around this unusual red dwarf. Moreover, this particular star is the same spectral type as Proxima Centauri, the Sun's nearest neighbour, which was shown to host at least one exoplanet, the famous Proxima b, in research published earlier this year.

21 Oct 2016

Thirty Meter Telescope: Fresh Hearings To take place

top-view-tmt-complexFresh hearings to decide the fate of the planned Thirty Meter Telescope (TMT) began Thursday in Hilo, Hawaii. The proceedings, which will decide whether the stalled construction work at the Big Island's Mauna Kea mountain will go ahead, are expected to last until next month.

The hearings come almost a year after the Supreme Court of Hawaii revoked a permit that would have allowed the construction of TMT to proceed atop the Mauna Kea summit. In a December ruling, the court said that the land board’s approval process was flawed.

On Thursday, environmental planner Perry White, principal author of the permit application filed by the University of Hawaii for the TMT project, argued that the project met the criteria for land use in a state-designated conservation district.

“White ... also noted that the Thirty Meter Telescope will be situated within the Maunakea area already sub-zoned for astronomy-related purposes,” the TMT project collaboration said in a statement. “He stressed that the project will not cause substantial adverse impacts to existing natural resources within the surrounding area, community or region.”

If constructed, the $1.4 billion telescope would be one of the world’s largest. Designed to operate in near-ultraviolet and mid-infrared wavelengths, the TMT would have a much higher resolution than that of the Hubble Space Telescope, allowing scientists to glimpse the universe in its infancy. Mauna Kea, which is a dormant volcano, is the ideal site as it provides a clear view of the sky for most part of the year, with little air and light pollution.

However, the site is considered sacred by some native Hawaiians, who say that the land contains burials, monuments, and places of worship venerated by them. Some environmentalists have also opposed the telescope’s construction, claiming that it would damage the ecosystem and harm the existing physical and environmental aspects of the land.

“This is a very simple case about land use,” Kealoha Pisciotta, a former telescope operator on Mauna Kea who has, over the past decade, led protests against the TMT, told the New York Times earlier this month. “It’s not science versus religion. We’re not the church. You’re not Galileo.”

20 Oct 2016

Milky Way: Secrets of galaxy revealed in most detailed hydrogen map yet

A team of scientists from Australia and Germany have created the most detailed hydrogen map ever produced of the Milky Way.

The map was pieced together using data collected over the past 10 years by two radio telescopes.

Perth-based astronomer Professor Lister Staveley-Smith, from the International Centre for Radio Astronomy Research (ICRAR), said other studies had mapped smaller areas of the galaxy in greater detail, but this map was the first of its quality covering the whole sky.

"We've kind of just put the data together from both hemispheres, a bit like putting maps of our own world together from the Northern Hemisphere and the Southern Hemisphere and picturing the globe for the first time," Professor Staveley-Smith told the ABC.

Astronomers used the two telescopes — in Parkes, New South Wales and Effelsberg, Germany — to study neutral hydrogen, the most abundant element in the universe.

"What it gives us is a map of the sky in hydrogen that normal telescopes, normal optical telescopes, can't see," Professor Staveley-Smith said.

The map, produced by a survey named the HI4PI, shows the Milky Way's finer details, including the boundaries of super shells created by giant explosions.
"We're seeing gas, we're seeing the interstellar medium, we're seeing the stuff which stars will later form from," he said.

"It's very important to understand the structure of gas in our own galaxy and the amount of gas in our own galaxy, its dynamics, in order that we can study the past evolution of the Milky Way and its likely future evolution."

An animation of the data shows two revolving spheres, similar to the globe of the Earth, with the sky plotted on each.

"Instead of viewing that sphere from the inside, which is what we do when we look at the sky, we can sort of paint that picture on the outside of a globe and sort of take ourselves outside and look at the sky the other way around," Professor Staveley-Smith said.

The map's sensitivity means scientists can see the two nearest galaxies to Earth — the Magellanic Clouds — and the stream of gas flowing from them across the Milky Way.

"I think this map, for the first time, will allow us to piece together the exact continuity of that stream across the two hemispheres," he said.

"That's what I'm most excited about."

Professor Staveley-Smith, who is based at the University of Western Australia, said only the Square Kilometre Array (SKA) telescope would produce maps of higher resolution.

The SKA, which will be the world's largest radio telescope, is being built in WA and South Africa.

Scientists from the HI4PI project have published their findings in the journal Astronomy and Astrophysics.

18 Oct 2016

Inter-stellar travel Poses Unique Threat to Astronauts


Exposure to highly energetic charged particles can lead to a range of potential central nervous system complications that can occur during and persist long after space travel, says a team of researchers led by Prof. Charles Limoli of the University of California, Irvine.

“The current findings raise much greater alarm. This is not positive news for astronauts deployed on a two-to-three-year round trip to Mars,” said Prof. Limoli, who is the senior author of a rodent study published in Monday’s issue of the journal Scientific Reports.

“The space environment poses unique hazards to astronauts. Exposure to these particles can lead to a range of potential central nervous system complications that can occur during and persist long after actual space travel – such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making.”

“Many of these adverse consequences to cognition may continue and progress throughout life,” he said.

For the study, rodents were subjected to charged particle irradiation — fully ionized oxygen and titanium — at the NASA Space Radiation Laboratory.

Six months after exposure, Prof. Limoli and his colleagues still found significant levels of brain inflammation and damage to neurons.

High resolution imaging revealed that the brain’s neural network was impaired through the reduction of dendrites and spines on these neurons, which disrupts the transmission of signals among brain cells. These deficiencies were parallel to poor performance on behavioural tasks designed to test learning and memory.

In addition, the researchers discovered that the radiation affected ‘fear extinction,’ an active process in which the brain suppresses prior unpleasant and stressful associations, as when someone who nearly drowned learns to enjoy water again.

“Deficits in fear extinction could make you prone to anxiety, which could become problematic over the course of a three-year trip to and from Mars,” Prof. Limoli said.

Most notably, these results mirror the six-week post-irradiation findings of Prof. Limoli’s 2015 study.

Similar types of more severe cognitive dysfunction are common in brain cancer patients who have received high-dose, photon-based radiation treatments.

“While dementia-like deficits in astronauts would take months to manifest, the time required for a mission to Mars is sufficient for such impairments to develop,” Prof. Limoli said.

“People working for extended periods on the International Space Station, however, do not face the same level of bombardment with galactic cosmic rays because they are still within the Earth’s protective magnetosphere.”

This work is part of NASA’s Human Research Program. Investigating how space radiation affects astronauts and learning ways to mitigate those effects are critical to further human exploration of space, and NASA needs to consider these risks as it plans for missions to Mars and beyond.

“Partial solutions are being explored. Spacecraft could be designed to include areas of increased shielding, such as those used for rest and sleep,” Prof. Limoli said.

“However, these highly energetic charged particles will traverse the ship nonetheless, and there is really no escaping them.”

17 Oct 2016

Air Force gets space telescope that can see the detail of satellites in orbit


The DARPA-developed Space Surveillance Telescope (SST) will this week get a new permanent home in Australia with the Air Force Space Command where it promises to rapidly bolster the nation’s ability to more quickly spot and track faint objects in space.

160927-D-ZZ999-002AThe Air Force, says the SST features unique image-capturing technology known as a curved charge coupled device (CCD) system,  as well as very wide field-of-view, large-aperture optics, and doesn't require the long optics train of a more traditional telescopes. The design makes the SST less cumbersome on its moveable mount, letting it survey the sky rapidly, the Air Force says. The telescope's mount uses advanced servo-control technology, making the SST one of the most agile telescopes of its size ever built.

With 2.2 million asteroid observations in 2014, 7.2 million in 2015 and hopes for 10 million in 2016, SST has already become the most prolific tool for asteroid observation in the world. SST also has discovered 3,600 new asteroids and 69 near-Earth objects, including four that carry a risk of hitting Earth, DARPA says.

From DARPA: "Beyond providing faster data collection, the SST is very sensitive to light, which allows it to see faint objects in deep space that currently are impossible to observe. The detection and tracking of faint objects requires a large aperture and fast optics.  The SST uses a 3.5 meter primary mirror, which is large enough to achieve the desired sensitivity. The system is an f/1.0 optical design, with a large-area mosaic CCD camera constructed from the curved imagers and a high-speed shutter allowing for fast scanning at the high sensitivity."

The SST has a number of missions, watching for debris in low earth orbit to help existing satellites avoid collisions chief among them, it also tracks objects in deep space and offers astronomers a wide-angle lens to take astronomical surveys of stars and comets, DARPA says.

A view of the M20 Trifid Nebula, taken by the Defense Advanced Research Projects Agency’s advanced Space Surveillance Telescope, soon to be transitioned to the Air Force and moved to Australia, where it will provide key space situational awareness from the southern hemisphere -- a still largely unexplored area of the geosynchronous belt. DoD photo Credit: Dod/DARPA

“Space is congested with tens of thousands of manmade objects as well as micro-meteors, asteroids and other natural satellites,” Lindsay Millard wrote in a post on the DARPA website. “[And] space is contested by a range of manmade threats that may have adverse effects on satellites.”

SST’s wide-open eye on the sky promises to become the most prolific tool ever for observing near-Earth objects and potentially harmful asteroids. The Air Force and Australian Government have announced plans to move SST to Australia and operate it jointly. From its new home, SST will provide key space situational awareness information from the southern hemisphere—an area of the geosynchronous belt that is currently sparsely observed, DARPA said.

Ripples in space key to understanding cosmic rays

mms_background_smallerIn a new study researchers at the Swedish Institute of Space Physics have used measurements from NASA's MMS (Magnetospheric MultiScale) satellites to reveal that there are ripples, or surface waves, moving along the surface of shocks in space. Such ripples in shocks can affect how plasma is heated and are potential sites of particle acceleration. These results have been published in the latest issue of Physical Review Letters.

Most visible matter in the Universe consists of ionized gas known as plasma. Shock waves in plasmas form around planets, stars and supernovas. Shocks in space plasma are efficient particle accelerators. Shocks in supernova explosions are thought to be the main source of cosmic rays – very high energy charged particles from space.


The details on how particles are accelerated and how plasma is heated at shocks in space plasmas are still unclear. The shock waves are usually considered planar surfaces but numerical simulations have previously showed that ripples can form on the surface of shock waves. The elusive ripples have been hard to study in space due to their small size and high speed.

A new study, by researchers at the Swedish Institute of Space Physics (IRF) in Uppsala, shows that these ripples do in fact exist in the Earth's bow shock. The study uses the newly launched MMS mission to study the shock in unprecedented detail.

"With the new MMS spacecraft we can, for the first time, resolve the structure of the bow shock at these small scales," says Andreas Johlander, PhD student at IRF, who led the study.

The results are of importance to the broader field of astrophysics where these ripples are thought to play an important role in accelerating particles to very high energies. The structure of the shock wave also determine how plasma is deflected and heated at shocks.

"These direct observations of shock ripples in a space plasma allow us to characterize the physical properties of the ripples. This brings us one step closer to understanding how shocks can produce cosmic rays," says Andreas Johlander.

Antimatter and the Sail to propel spacecraft to our nearest star


by Paul Gilster on October 17, 2016

An antimatter probe to a nearby star? The idea holds enormous appeal, given the colossal energies obtained when normal matter annihilates in contact with its antimatter equivalent. But as we’ve seen through the years on Centauri Dreams, such energies are all but impossible to engineer. Antimatter production is infinitesimal, the by-product of accelerators designed with a much different agenda. Moreover, antimatter storage is hellishly difficult, so that maintaining large quantities in a stable condition requires multiple breakthroughs.

All of which is why I became interested in the work Gerald Jackson and Steve Howe were doing at Hbar Technologies. Howe, in fact, became a key source when I put together the original book from which this site grew. This was back in 2002-2003, and I was captivated with the idea of what could be called an ‘antimatter sail.’ The idea, now part of a new Kickstarter campaign being launched by Jackson and Howe, is to work with mere milligrams of antimatter, allowing antiprotons to be released from the spacecraft into a uranium-enriched, five-meter sail.

Reacting with the uranium, the antimatter produces fission fragments that create what could be considered a nuclear-stimulated ablation blowing off the carbon-fiber sail. As to the reaction itself, Jackson and Howe would use a sheet of depleted uranium U-238 with a carbon coating on its back side. Here’s how the result is described in the Kickstarter material now online:

When antiprotons… drift onto the front surface, their negative electrical charge allows them to act like an orbiting electron, but with different quantum numbers that allow the antiprotons to cascade down into the ground orbital state. At this point it annihilates with a proton or neutron in the nucleus. This annihilation event causes the depleted uranium nucleus to fission with a probability approaching 100%, most of the time yielding two back-to-back fission daughters.

Now we get into a serious kick for the spacecraft:

A fission daughter travelling away from the sail at a kinetic energy of 1 MeV/amu has a speed of approximately 13,800 km/sec, or 4.6% of the speed of light. The other fission daughter is absorbed by the sail, depositing its momentum into the sail and causing the sail (and the rest of the ship) to accelerate.

The concept relies, as Jackson said in a recent email, on using antimatter as a spark plug rather than as a fuel, converting the energy from proton-antiproton annihilations into propulsion.


Image: The original antimatter probe concept. Credit: Gerald Jackson/Hbar Technologies.

The current work grows out of a 2002 grant from NASA’s Institute for Advanced Concepts but the plan is to develop the idea far beyond the Kuiper Belt mission Jackson and Howe initially envisioned. Going interstellar would take not milligrams but tens of grams of antimatter, far beyond today’s infinitesimal production levels. In fact, while the Fermi National Accelerator laboratory has been able to produce no more than 2 nanograms of antimatter per year, even that is high compared to CERN’s output (the only current source), which is 100 times smaller.

Even so, interest in antimatter remains high because of its specific energy — two orders of magnitude larger than fusion and ten orders of magnitude larger than chemical reactions — making further research highly desirable. If the fission reaction the antimatter produces within the sail is viable, we will be able to demonstrate a way to harness those energies, with implications for deep space exploration and the possibility of interstellar journeys.

The original NIAC work led to a sail 5-meters in diameter, with a 15-micron thick carbon layer and a uranium coating 293 microns thick. Interestingly, the study showed that the sail had sufficient area to remove any need for active cooling of the surface. Indeed, the steady-state temperature of the sail would be 570 Celsius, below the melting point of uranium.

The work was based around a 10 kg instrument payload to be delivered to 250 AU within 10 years. Turning to interstellar possibilities, Breakthrough Star shot has been talking about reaching 20 percent of light speed with a beamed laser array pushing small sails. Jackson and Howe now seek roughly 5 percent of c, making for a mission of less than a century to reach Proxima Centauri, where we already know an interesting planet awaits.

But here’s a significant difference: Unlike Breakthrough Star shot's flyby assumptions, the antimatter sail mission concept is built around decelerating and attaining orbit around the target star. In the absence of magsail braking against Proxima’s stellar wind, this would presumably also involve antimatter, braking with the same methods to allow for long-term scientific investigation, thus avoiding the observational challenges of a probe pushing past a small and probably tidally-locked planet at 20 percent of light speed.

Here’s how Jackson describes deceleration in his recent email:

Our project considers deceleration and orbit about the destination star a mission requirement. There are serious implications for spacecraft velocity when the requirement of deceleration at the destination is imposed. Either drag or some other mechanism needs to be invoked at the destination, or enough extra fuel must be accelerated in order to accomplish a comparable deceleration. Because the rocket equation equates probe velocity with mass utilization, a staged spacecraft architecture is envisioned wherein a more massive booster accelerates the spacecraft and a smaller second stage decelerates into the destination solar system.

The discovery of Proxima b, that interesting planet evidently in the habitable zone around the nearest star, continues to energize the interstellar community. The Kickstarter campaign, just underway and with a goal of $200,000, hopes to upgrade earlier antimatter sail ideas into the interstellar realm. Tomorrow I want to say a few more things about the antimatter sail and the issues the Kickstarter campaign will address as it expands the original work.

China to launch two-man space mission

135757936_14765992323591nChina will launch its sixth manned space mission Shenzhou-11 today, officials with the space programme said, taking the country closer to its ambition of setting up a permanently manned space station by 2022.

After the 7.30am launch in the remote north-western province of Gansu, the mission's two astronauts will dock in two days with the orbiting space lab Tiangong-2 which was launched last month. They'll spend 33 days on the country's new space lab conducting experiments in physics, medicine and biology.

Thirty-three days probably doesn't seem like much — one Russian cosmonaut spent 438 days up there — but it's actually part of some major plans that China has for its space program.

Shenzhou-11, China's sixth manned mission, will end the country's three-year absence in human spaceflight.

It will be Mr Jing Haipeng's third flight into space following missions in 2008 and 2012. The former fighter jet pilot will also be celebrating his 50th birthday in space.

"Being an astronaut is my career. Space exploration is my job as well as my pursuit. It is challenging, risky, even dangerous. But honestly, this is what I love, this is what I enjoy," said Mr Jing, adding that China has improved its ability to deal with emergencies, first aid and space experiments.

Mr Jing is joined by 38-year-old Chen Dong. With a safe flight record of 1,500 hours as an air force pilot, Mr Chen was selected to join China's second batch of astronauts in May 2010 and was picked for the Shenzhou-11 mission in June. This will be his first space flight.

"This mission is characterised by its longer duration and more tests," Mr Chen told reporters in a televised news conference.

The pair will conduct research related to in-orbit equipment repairs, aerospace medicine, space physics and biology, atomic space clocks and solar storm research.

"I am looking forward to viewing Earth and our motherland from space," said Mr Chen, adding that he hoped to be able to take many photos and enjoy the celestial scenery.”

16 Oct 2016

ESA probe Schiaparelli prepares to land on Mars

untitledA Mars lander is due to leave its mothership on Sunday and head toward the red planet’s surface to test technologies for Europe’s planned first Mars rover, which will search for signs of past and present life.

After a seven-month journey from Earth as part of the European-Russian ExoMars program, the Schiaparelli lander is expected to separate from spacecraft Trace Gas Orbiter (TGO) at 10:42 a.m. EDT and start a three-day descent to the surface.

Schiaparelli represents only the second European attempt to land a craft on Mars, after a failed mission by the British landing craft Beagle 2 in 2003.

Landing on Mars, Earth’s neighbour some 35 million miles (56 million km) away, is a notoriously difficult task that has bedevilled most Russian efforts and given NASA trouble as well. The United States currently has two operational rovers on Mars, Curiosity and Opportunity.

But a seemingly hostile environment has not detracted from the allure of Mars, with U.S. President Barack Obama recently highlighting his pledge to send people to the planet by the 2030s.

untitledElon Musk’s SpaceX is developing a massive rocket and capsule to transport large numbers of people and cargo to Mars with the ultimate goal of colonizing the planet, with Musk saying he would like to launch the first crew as early as 2024.

The primary goal of ExoMars is to find out whether life has ever existed on Mars. The current spacecraft carries an atmospheric probe to study trace gases such as methane, around the planet.

Scientists believe that methane, a chemical that on Earth is strongly tied to life, could stem from micro-organisms that either became extinct millions of years ago and left gas frozen below the planet’s surface, or that some methane-producing organisms still survive.

The second part of the ExoMars mission, delayed to 2020 from 2018, will deliver a European rover to the surface of Mars. It will be the first with the ability to both move across the planet’s surface and drill into the ground to collect and analyse samples.

The ExoMars 2016 mission is led by the European Space Agency (ESA), with Russia’s Roscosmos supplying the launcher and two of the four scientific instruments on the trace gas orbiter. The prime contractor is Thales Alenia Space, a joint venture between Thales and Finmeccanica.

The cost of the ExoMars mission to ESA, including the second part due in 2020, is expected to be about 1.3 billion euros ($1.4 billion). Russia’s contribution comes on top of that.

In 2018, NASA also plans to launch a Mars spacecraft, a satellite known as InSight and designed to study the deep interior of Mars.

(Reporting by Maria Sheahan; Editing by Dominic Evans)

15 Oct 2016

NASA’s Moon mapper Ewen Whitaker dies

hartmann_spotEwen Whitaker never walked on the moon but he mapped it and named its features. His work made it possible to select sites where Neil Armstrong and the Apollo astronauts were able to land safely and explore the lunar surface.

Whitaker, the last original member of the University of Arizona's Lunar and Planetary Laboratory, died Tuesday at the age of 94.

He was hired by LPL Director Gerard Kuiper to help create an atlas of the moon, first at Yerkes Observatory at the University of Chicago and later at the UA, where Kuiper established the Lunar and Planetary Lab in 1960.

When President John F. Kennedy announced in 1961 that America would land on the moon by the end of the decade, moon-mapping became critical to that effort and the lab grew exponentially.

According to the Lunar and Planetary Lab's website history, Whitaker pioneered the technique of combining ultra-violet and infrared images of the moon's surface to make compositional maps. The maps were "instrumental to the selection of landing sites for the Surveyor and Apollo missions."

Planetary scientist William Hartmann, one of the laboratory's first three graduate students, said Whitaker was an unassuming man with "a wonderful sense of humor. He was this jolly, witty English guy, just a generally wonderful person to be around."

"When the famous scientists of the day would visit, it was really remarkable — they did not know as much about the moon and planets as Ewen did. He knew each mountain and each crater and each crag and he knew the names of them," Hartmann said.


Whitaker was born in England and was astronomer at the Royal Observatory in Greenwich when he saw Kuiper speak at a conference in Ireland in 1955.

Kuiper was enlisting help for creating a moon atlas, something Whitaker had already started. Whitaker, in a history he wrote about the early days of LPL, said he later found out that he was the only one to respond to Kuiper's request.

At the UA, he wrote: "We started up in very humble surroundings. We had one Quonset hut where the Science Library is now."

The team soon moved to the new Physics and Atmospheric Sciences building and by 1965, with the space race heating up, Kuiper secured NASA funds for a new building, now named the Kuiper Space Sciences Building.

Whitaker retired from the UA in 1987, but he continued to participate in its programs, especially the Apollo gatherings, said Maria Schuchardt, data manager of the Space Imagery Center at the lab.

"Throughout the years, he didn’t have a computer, so a lot of people would get in touch with me to ask him questions about the moon. The last time I saw him, somebody was asking about the Surveyor mission, so I dropped the email off at his house. He was always kind and gentle and just a delight to be with," she said.

LPL Director Tim Swindle called Whitaker "our remaining link to the founding of the lab and very much a part of its history."

"He was gracious, he was lovable, and in the 1960s, he knew more about the moon than any person in history."

Two Undiscovered Dark Moons Appear to Be Hiding inside Uranus’ rings

untitledAfter re-examining data acquired by the Voyager 2 spacecraft, astronomers have detected wavy patterns in two of Uranus’s dark system of rings—patterns that may be indicative of two undiscovered moons.

Like the other gas giants in our solar system, Uranus features a ring system, though it’s not nearly as spectacular as the one around Saturn. And like the other gas giants, Uranus hosts a batch of natural satellites—27 to be exact. New research suggests this number might have to be revised; data collected by Voyager 2 during its historic 1986 flyby hints at two undiscovered moons lurking around a pair of Uranus’ rings.

The suspected new moons reside in Alpha and Beta—the 5th and 6th rings.

After the ε ring, the α and β rings are the brightest of Uranus's rings. Like the ε ring, they exhibit regular variations in brightness and width. They are brightest and widest 30° from the apoapsis and dimmest and narrowest 30° from the periapsis. The α and β rings have sizable orbital eccentricity and non-negligible inclination. The widths of these rings are 4.8–10 km and 6.1–11.4 km, respectively.  The equivalent optical depths are 3.29 km and 2.14 km, resulting in normal optical depths of 0.3–0.7 and 0.2–0.35, respectively. During a ring plane-crossing event in 2007 the rings disappeared, which means they are geometrically thin like the ε ring and devoid of dust. However, the same event revealed a thick and optically thin dust band just outside the β ring, which was also observed earlier by Voyager 2. The masses of the α and β rings are estimated to be about 5 × 1015 kg (each)—half the mass of the ε ring.


Running time : 30 minutes  Presented by Richard Pearson FRAS.
October 2016


Uranus is almost 20 times farther from the sun than the Earth, making direct observations difficult. Voyager 2 found 10 moons when it visited the planet in 1986, tripling the number of moons known to orbit the gas giant. But it appears the probe’s satellite-hunting days aren’t over just yet. Planetary scientists Rob Chancia and Matthew Hedman from the University of Idaho recently revisited Voyager 2's old data, and they noticed something peculiar in two of Uranus’ 13 rings, Alpha and Beta.

The two rings exhibit a series of wavy patterns consistent with the presence of two tiny moons. “These patterns may be wakes from small moonlets orbiting exterior to these rings,” write the researchers in their study.

Importantly, these observations are consistent with how Uranus’ other moons, such as Cordelia and Ophelia, are exerting gravitational pressure on the dust, rocks, and ice within the rings, herding the particles along a narrow formation.

If these moons exist, they’re quite dark and very tiny, measuring a mere two to nine miles (four to 14 km) across. That would make them smaller than any other known moon to orbit the planet, which explains why Voyager 2 wasn’t able to detect them directly.

Armed with this possibility, the researchers are planning to inspect Uranus with the Hubble Space Telescope. Failing that, we could always send a new space probe. It’s been three decades since our last visit to Uranus, after all.

14 Oct 2016

Ringed-planet 20 times bigger than Saturn discovered in the far south


About 420 light years from our solar system, there is a celestial body that looks like Saturn on steroids. It lies in the southern constellation of Centaurus: RA 14h 07m 47.93s Declination -39 45’ 42.7” . A relatively young star, its age is estimated to be 16 million years, and its mass is about 90% that of the Sun's. The star has an apparent magnitude of 12.3 and requires a telescope to be seen.

Its rings are about 200 times larger than its counter part here, measuring about 75 million miles in diameter. The ring system is so large, in fact, that scientists aren’t sure why it doesn’t get ripped apart by the gravity of the star it orbits.

The discovery of the J1407 system and its unusual eclipses were first reported by a team led by University of Rochester astronomer Eric Mamajek in 2012. The existence and parameters of the ring system around the sub stellar companion J1407b were deduced from the observation of a very long and complex eclipse of the previously anonymous star J1407 during a 56-day period during April and May 2007. The low-mass companion J1407b has been referred to as a "Saturn on steroids"or “Super Saturn” due to its massive system of circumplanetary rings with a radius of approximately 90 million km (0.6 AU). The orbital period of the ringed companion J1407b is estimated to be around a decade (constrained to 3.5 to 13.8 years), and its most probable mass is approximately 13 to 26 Jupiter masses, but with considerable uncertainty. The ringed body can be ruled out as being a star with mass of over 80 Jupiter masses at greater than 99% confidence. The ring system has an estimated mass similar to that of the Earth. A gap in the ring system at about 61 million km (0.4 AU) from its centre is considered to be indirect evidence of the existence of an exomoon with mass up to 0.8 Earth masses.

One reason the rings might stay intact has to do with the direction in which they spin around the object at their centre, called J1407b. Scientists are not sure whether J1407b is a gigantic planet that measures may times larger than Saturn, or a failed star called a brown dwarf.

There is a point in J1407b’s lopsided orbit when it comes close to its sun like star, which should disrupt the rings. But the rings remain unscathed for the most part because they spin around J1407b in the opposite direction that the object orbits around its star, according to a paper accepted in the journal Astronomy & Astrophysics and posted online on Tuesday.


“We ran a lot of simulations of possible orbits for the planet to see if they could survive or not,” said Steven Rieder, an astronomer at the Riken Institute in Japan and lead author of the paper. “If you have the planet moving clockwise and the rings moving counter clockwise, that is much more stable than if they move in the same direction, clockwise,” he said.

The team realized that if the object and its rings spin out of sync with each other, the ice and debris that make up the ring system are never too close to the sun for too long, which makes them more stable. That means they can stay together in a ring formation in the face of the star’s intense gravity.

“So we got rid of one problem,” said Matthew Kenworthy from Leiden University in the Netherlands and co-author of the study, “but now we’ve got the problem of how the heck do you get rings spinning the other way around?”

Their prevailing theory for the retrograde spinning is that either the ring system or the celestial body was involved in some sort of catastrophic collision that completely altered how it spins, rather than forming naturally.

13 Oct 2016

OSIRIS REx in good shape & begins manoeuvres for Earth flyby in 2017

Spacecraft-Cruise-ImageNASA’s OSIRIS-REx spacecraft fired its Trajectory Correction Manoeuvre (TCM) thrusters for the first time Friday in order to slightly adjust its trajectory on the outbound journey from Earth to the asteroid Bennu. The spacecraft’s planned first Trajectory Correction Manoeuvre (TCM-1) began at 1 p.m. EDT and lasted for approximately 12 seconds. The manoeuvre changed the velocity of the spacecraft by 1.1 mile per hour (50 centimetres per second) and used approximately 18 ounces (.5 kilogram) of fuel.  The spacecraft is currently about 9 million miles (14.5 million kilometres) from Earth.

TCM-1 was originally included in the spacecraft’s flight plan to fine-tune its trajectory if needed after the mission’s Sept. 8 launch. The ULA Atlas V’s launch performance was so accurate, however, that the spacecraft’s orbit had no practical need for correction. Instead, the OSIRIS-REx mission team used the Oct. 7 manoeuvre to test the TCM thrusters and as practice to prepare for a much larger propulsive manoeuvre scheduled in December.

The mission had allocated approximately 388 ounces (11 kilograms) of propellant for TCM-1 to create a velocity change of up to 26 miles per hour (11.6 meters per second), had it been necessary. The unused propellant from this event provides more fuel margin for the spacecraft’s asteroid proximity operations once OSIRIS-REx arrives at Bennu.

To track today’s manoeuvre, the OSIRIS-REx mission’s navigation team monitored the Doppler shift in radio signals between the spacecraft and the Deep Space Network antenna at the Goldstone Observatory in California. After 44 seconds—the current one-way light time delay between the spacecraft and Earth—the team received the first manoeuvre data from the spacecraft. Over the next week, the navigation team will process daily spacecraft tracking data to determine the precise effect of the burn.

The OSIRIS-REx spacecraft has four different kinds of thrusters providing considerable redundancy in its ability to manoeuvre on its way to the surface of Bennu and back. OSIRIS-REx began using its Attitude Control System (ACS) thrusters shortly after launch to keep the spacecraft oriented, so that its solar arrays point toward the sun and its communication antennas point toward Earth. Today was the first use of its larger Trajectory Correction Manoeuvre (TCM) thrusters. In December OSIRIS-REx will use its largest thrusters, the Main Engine (ME) thrusters, to target the spacecraft for its Earth Gravity Assist scheduled for Sept. 22, 2017. Its smallest thrusters, the Low Thrust Reaction Engine Assembly (LTR) thrusters, will be used for the delicate manoeuvres close to the surface of the asteroid Bennu.

NASA’s Goddard Space Flight Center provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s observation planning and processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing spacecraft flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for its Science Mission Directorate in Washington.

12 Oct 2016

Iran to Send Astronauts into Space in “5 Years”

13921003000609_PhotoI"We will send man into the space to the suborbital level in the next five years and we will have an orbital launch until 2025," Ommi told reporters in a press conference in Tehran today.

A suborbital spaceflight is a flight in which the spacecraft reaches space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it does not complete one orbital revolution.

Ommi explained that Iran has held negotiations with Russia and China on the project, but has eventually selected Russia for the launch, given its long experience in aerospace industry.

Earlier this month, Director of Iranian Space Agency (ISA) Mohsen Bahrami has also announced the country's plans to send astronauts into space in cooperation with Russia.

"The project to send man into space is still a priority of the ISA and we have even held some negotiations with Russia to send astronauts into space," Bahrami told reporters in Tehran.

Elsewhere, he referred to Iran's talks with Eutelsat, Intelsat, Sputnik, Asia sat and SCS satellite operators belonging to the European and Asian states, including France, Britain, Russia, China, South Korea and Japan, and said, "After these negotiations and inking the initial contract, we intend to buy a remote sensing and a telecommunication satellites."

Bahrami also expressed the hope for the start of interactions with the National Aeronautics and Space Administration (NASA) in the future, saying that "NASA is an independent international agency whose executive branch is just in the US".

Bahrami had announced last month the country's plans to send one or two satellites into the orbit by the end of the current Iranian year (March 20), adding that an optical telescope will also start work in October.

"This year, we will send Dousti (Friendship) satellite into space and we will also be ready for a second launch late this year or early next year," Bahrami said.

He also said that the project to install the ground-based optical telescope system to observe objects in space is being implemented at Mahdasht space centre near Tehran and will be launched within a month.

Iranian Minister of Communications and Information Technology Mahmoud Vaezi announced in August that the country's experts have started efforts to build a remote sensing satellite with environmental applications.

"The work on building a remote sensing satellite started last week," Vaezi told reporters in the Northern city of Sari.

"By building the satellite, the country will further develop in environmental, agricultural, water and soil fields," he added.

In February 2015, Iran’s domestically-made National Fajr (Dawn) satellite was launched into orbit and started transmitting data to its stations on earth.

The satellite made its first contact with its ground stations hours after it was put into the orbit.

Fajr satellite is technically characterized by an orbit which could promote from 250 to 450 kilometres through a thruster or an engine.

Equipped with GPS navigation system, Fajr, weighing 52 kilos, is the fourth Iranian-made satellite which was put into orbit after three others between 2009 and 2012.

After Iran launched its first locally-built satellite, Omid (Hope), in 2009, it put two other satellites including, Rasad (Observation), and Navid-e Elm-o Sanat (Harbinger of Science and Industry) into space.