Time Space Science

A novel bacterium -- trapped more than three kilometres under glacial ice in Greenland for over 120,000 years -- may hold clues as to what life forms might exist on other planets.

Dr Jennifer Loveland-Curtze and a team of scientists from Pennsylvania State University report finding the novel microbe, which they have called Herminiimonas glaciei, in the current issue of the International Journal of Systematic and Evolutionary Microbiology. The team showed great patience in coaxing the dormant microbe back to life; first incubating their samples at 2˚C for seven months and then at 5˚C for a further four and a half months, after which colonies of very small purple-brown bacteria were seen.

H. glaciei is small even by bacterial standards – it is 10 to 50 times smaller than E. coli. Its small size probably helped it to survive in the liquid veins among ice crystals and the thin liquid film on their surfaces. Small cell size is considered to be advantageous for more efficient nutrient uptake, protection against predators and occupation of micro-niches and it has been shown that ultramicrobacteria are dominant in many soil and marine environments.

Most life on our planet has always consisted of microorganisms, so it is reasonable to consider that this might be true on other planets as well. Studying microorganisms living under extreme conditions on Earth may provide insight into what sorts of life forms could survive elsewhere in the solar system.

"These extremely cold environments are the best analogues of possible extraterrestrial habitats", said Dr Loveland-Curtze, "The exceptionally low temperatures can preserve cells and nucleic acids for even millions of years. H. glaciei is one of just a handful of officially described ultra-small species and the only one so far from the Greenland ice sheet; studying these bacteria can provide insights into how cells can survive and even grow under extremely harsh conditions, such as temperatures down to -56˚C, little oxygen, low nutrients, high pressure and limited space."

"H. glaciei isn't a pathogen and is not harmful to humans", Dr Loveland-Curtze added, "but it can pass through a 0.2 micron filter, which is the filter pore size commonly used in sterilization of fluids in laboratories and hospitals. If there are other ultra-small bacteria that are pathogens, then they could be present in solutions presumed to be sterile. In a clear solution very tiny cells might grow but not create the density sufficient to make the solution cloudy."


http://www.sgm.ac.uk/

A team of NASA and university scientists has achieved the first definitive detection of methane in the atmosphere of Mars. This discovery indicates the planet is either biologically or geologically active.


The team found methane in the Martian atmosphere by carefully observing the planet throughout several Mars years with NASA's Infrared Telescope Facility and the W.M. Keck telescope, both at Mauna Kea, Hawaii. The team used spectrometers on the telescopes to spread the light into its component colors, as a prism separates white light into a rainbow. The team detected three spectral features called absorption lines that together are a definitive signature of methane.

"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Michael Mumma of NASA's Goddard Space Flight Center in Greenbelt, Md. "At northern mid-summer, methane is released at a rate comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, Calif." Mumma is lead author of a paper describing this research that will appear in Science Express on Thursday.

Methane, four atoms of hydrogen bound to a carbon atom, is the main component of natural gas on Earth. Astrobiologists are interested in these data because organisms release much of Earth's methane as they digest nutrients. However, other purely geological processes, like oxidation of iron, also release methane.

"Right now, we do not have enough information to tell whether biology or geology -- or both -- is producing the methane on Mars," Mumma said. "But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, 'hey, find out what this means.' "

If microscopic Martian life is producing the methane, it likely resides far below the surface where it is warm enough for liquid water to exist. Liquid water is necessary for all known forms of life, as are energy sources and a supply of carbon.

"On Earth, microorganisms thrive about 1.2 to 1.9 miles beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen and oxygen," Mumma said. "The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon. Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons."

It is possible a geologic process produced the Martian methane, either now or eons ago. On Earth, the conversion of iron oxide into the serpentine group of minerals creates methane, and on Mars this process could proceed using water, carbon dioxide and the planet's internal heat. Although there is no evidence of active volcanism on Mars today, ancient methane trapped in ice cages called clathrates might be released now.

"We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane," said co-author Geronimo Villanueva of the Catholic University of America in Washington. "The plumes were emitted during the warmer seasons, spring and summer, perhaps because ice blocking cracks and fissures vaporized, allowing methane to seep into the Martian air."

According to the team, the plumes were seen over areas that show evidence of ancient ground ice or flowing water. Plumes appeared over the Martian northern hemisphere regions such as east of Arabia Terra, the Nili Fossae region, and the south-east quadrant of Syrtis Major, an ancient volcano about 745 miles across.

One method to test whether life produced this methane is by measuring isotope ratios. Isotopes of an element have slightly different chemical properties, and life prefers to use the lighter isotopes. A chemical called deuterium is a heavier version of hydrogen. Methane and water released on Mars should show distinctive ratios for isotopes of hydrogen and carbon if life was responsible for methane production. It will take future missions, like NASA's Mars Science Laboratory, to discover the origin of the Martian methane.

The research was funded by the Planetary Astronomy Program at NASA Headquarters in Washington and the Astrobiology Institute at NASA's Ames Research Center in Moffett Field, Calif. The University of Hawaii manages NASA's Infrared Telescope Facility.

http://www.nasa.gov/centers/goddard/home/index.html

Many of the organic molecules that make up life on Earth have also been found in space. A University of Michigan astronomer will use the Herschel Space Observatory to study these chemical compounds in new detail in the warm clouds of gas and dust around young stars.
They hope to gain insights into how organic molecules form in space, and possibly, how life formed on Earth.

"The chemistry of space makes molecules that are the precursors of life. It's possible that the Earth didn't have to make these things on its own, but that they were provided from space," said Ted Bergin, an associate professor in the Department of Astronomy.

Bergin is a co-investigator on the Heterodyne Instrument for the Infrared aboard Herschel and a principal investigator on one of its key observing programs. Herschel, a European Space Agency mission with NASA participation, is scheduled to launch May 6. An orbiting telescope that will unlock new wavelengths on the electromagnetic spectrum, it will allow astronomers to observe at the far-infrared wavelengths where organic molecules and water emit their chemical signatures.

"We'll be studying the full extent of chemistry in space and we hope to learn what types of organics are out there as a function of their distance from a star," Bergin said. "And we want to understand the chemical machinery that led to the formation of these organics."

Meteorites flecked with amino acids, which make proteins, have fallen to Earth from space. In faraway galaxies and stellar nurseries, astronomers have detected complex organic sugar and hydrocarbon molecules that are key components in chlorophyll in plants and RNA. Bergin expects to detect tens if not hundreds of these kinds of compounds---some of which have never been found before outside the Earth.

He is also involved in a Herschel project to look for water molecules in space. Traces of water in warm clouds of gas and dust around young stars could hold clues to how water forms and behaves in space, and how this elixir of life came to be so abundant on Earth. Scientists believe water got to Earth in a similar way as organic molecules.

"Most of the water in the solar system is not where we are, but further out in the solar system," Bergin said. "Most theories suggest that the Earth formed dry and impacts from asteroids or other objects provided the water here."


http://www.umich.edu/

A Duke University professor and his graduate student have discovered a universal principle that unites the curious interplay of light and shadow on the surface of your morning coffee with the way gravity magnifies and distorts light from distant galaxies.


They think scientists will be able to use violations of this principle to map unseen clumps of dark matter in the universe.

Light rays naturally reflect off a curve like the inside surface of a coffee cup in a curving, ivy leaf pattern that comes to a point in the center and is brightest along its edge.

Mathematicians and physicists call that shape a "cusp curve," and they call the bright edge a "caustic," based on an alternative dictionary definition meaning "burning bright," explains Arlie Petters, a Duke professor of mathematics, physics and business administration. "It happens because a lot of light rays can pile up along curves."

Drawn by the mathematically-inclined artist Leonardo da Vinci in the early 16th century, caustics can be seen elsewhere in everyday life, including sunlight reflecting across a swimming pool's surface and choppy wave-light patterns reflecting off a boat hull.

Caustics also show up in gravitational lensing, a phenomenon caused by galaxies so massive that their gravity bends and distorts light from more distant galaxies. "It turns out that their gravity is so powerful that some light rays are also going to pile up along curves," said Petters, a gravitational lensing expert.

"Mother Nature has to be creating these things," Petters said. "It's amazing how what we can see in a coffee cup extends into a mathematical theorem with effects in the cosmos."

From the vantage point of Earth, the entire cosmos looks like a vast interplay of gravity and light that can extend far back into spacetime. "As with any illumination pattern, some areas will be brighter than others," Petters said. "And the brightest parts will be along these caustic curves."

Interpreting data from telescope surveys correctly requires understanding the distortions inherent in lensing, which sometimes warps a more distant point of light into multiple and magnified copies of themselves.

Petters and other researchers have previously found that, if such a light source seems to be juxtaposed within the confines of a caustic arch, two duplicate images will appear to be positioned abnormally close to each other and also seem equally bright. And because these clones are of seemingly equal brightness, subtracting one luminosity from the other results in a difference of zero.

In an article appearing in the March 23 Journal of Mathematical Physics, Petters and graduate student Amir Aazami extended the mathematics of such relatively simple examples to include what Petters called "higher order caustics." In such situations the interplay of light and gravity may extend further into spacetime and undergo various forms of "caustic metamorphosis" in the process.

Aazami was informally testing out a special case of their evolving caustics theorem called an "ellyptic umbilic" by using a technical computing software program called Mathematica when he noticed a pattern.

"It kept getting zero over and over again," Aazami said, no matter what scenario he tried the software on. "So I thought, 'it's making a mistake.' And I went back and looked again, and I kept getting zero. And I said, 'this is beginning to make sense!' That was the 'Ah Ha!' moment."

Petters realized his graduate student had found a universal mathematical principle so pervasive that it can impose balance on the most complicated gravitational lensing illusions. For instance, if lensing produces four light source copies of uneven brightnesses, the relative dimness of some is precisely balanced by the relative luminosity of others so they cancel each other out.

"It's miraculous that they cancel out," Petters said. "This relates to very sophisticated mathematics that you would never think could have anything to do with nature."

The Duke researchers said that for the simplest caustics, the theorem has already been corroborated by a few actual gravitational lensing observations. And they expect the higher order caustics to be observed once the Large Synoptic Survey Telescope (LSST), now being assembled in Chile, begins what Petters called "the most massive survey of the sky known" in a few years.

"We feel very confident that these universal invariants will show themselves in the data to come from the LSST," he said.

Another scenario he predicts are exceptions to the rule: "For one of the higher order caustics, if there are two pairs of lensed images that are close to each other but not equally bright, then the theorem is violated," he said.

"The reason would be some substructure in the galaxy," he said, likely dark matter near one of the images that causes it to be demagnified.

Dark matter is a mysterious substance that astronomers cannot directly observe but can "sense" by its gravitational tug on light. By using the LSST in conjunction with their theorem, astronomers "would be able to identify dark matter substructures in complex galactic systems," Petters predicted

The research was supported by the National Science Foundation.


http://www.duke.edu/

Researchers trying to understand how the planets formed have uncovered a new clue by analysing meteorites that are older than the earth.

The research shows that the process which depleted planets and meteorites of so-called volatile elements such as zinc, lead and sodium, must have been one of the first things to happen in our nebula.

The implication of this clue is that 'volatile depletion' may be an inevitable part of planet formation - a feature not just of our Solar System, but of many other planetary systems too.

The researchers at Imperial College London reached their conclusions after analysing the composition of primitive meteorites, coal-like rocks that are older than the earth and which have barely changed since the Solar System was made up of fine dust and gas.

Their analysis, published today in the Proceedings of the National Academy of Sciences, shows that all the components that make up these rocks are depleted of volatile elements. This means that volatile element depletion must have occurred before the earliest solids had formed.

Dr. Phil Bland, from Imperial's Department of Earth Science and Engineering, who led the research, explains: "Studying meteorites helps us to understand the initial evolution of the early Solar System, its environment, and what the material between stars is made of. Our results answer one of a huge number of questions we have about the processes that converted a nebula of fine dust and gas into planets."

For planetary scientists, the most valuable meteorites are those that are found immediately after falling to earth, and so are only minimally contaminated by the terrestrial environment. The researchers analysed around half of the approximately 45 primitive meteorite falls in existence around the world.

All of the terrestrial planets in the Solar System as far out as Jupiter, including Earth, are depleted of volatile elements. Researchers have long known that this depletion must have been an early process, but it was unknown whether it occurred at the beginning of the formation of the Solar System, or a few million years later.

Dr. Phil Bland is a member of the Impacts and Astromaterials Research Centre (IARC), which combines planetary science researchers from Imperial College London and the Natural History Museum.


http://www3.imperial.ac.uk/media

On the evidence to date, our solar system could be fundamentally different from the majority of planetary systems around stars because it formed in a different way. If that is the case, Earth-like planets will be very rare. After examining the properties of the 100 or so known extrasolar planetary systems and assessing two ways in which planets could form, Dr Martin Beer and Professor Andrew King of the University of Leicester, Dr Mario Livio of the Space Telescope Science Institute and Dr Jim Pringle of the University of Cambridge flag up the distinct possibility that our solar system is special in a paper to be published in the Monthly Notices of the Royal Astronomical Society.


In our solar system, the orbits of all the major planets are quite close to being circular (apart from Pluto’s, which is a special case), and the four giant planets are a considerable distance from the Sun. The extrasolar planets detected so far - all giants similar in nature to Jupiter – are by comparison much closer to their parent stars, and their orbits are almost all highly elliptical and so very elongated.

‘There are two main explanations for these observations,’ says Martin Beer. ‘The most intriguing is that planets can be formed by more than one mechanism and the assumption astronomers have made until now - that all planets formed in basically the same way - is a mistake.’

In the picture of planet formation developed to explain the solar system, giant planets like Jupiter form around rocky cores (like the Earth), which use their gravity to pull in large quantities of gas from their surroundings in the cool outer reaches of a vast disc of material. The rocky cores closer to the parent star cannot acquire gas because it is too hot there and so remain Earth-like.

The most popular alternative theory is that giant planets can form directly through gravitational collapse. In this scenario, rocky cores - potential Earth-like planets - do not form at all. If this theory applies to all the extrasolar planet systems detected so far, then none of them can be expected to contain an Earth-like planet that is habitable by life of the kind we are familiar with.

However, the team are cautious about jumping to a definite conclusion too soon and warn about the second possible explanation for the apparent disparity between the solar system and the known extrasolar systems. Techniques currently in use are not yet capable of detecting a solar-system look-alike around a distant star, so a selection effect might be distorting the statistics - like a fisherman deciding that all fish are larger than 5 inches because that is the size of the holes in his net.

It will be another 5 years or so before astronomers have the observing power to resolve the question of which explanation is correct. Meanwhile, the current data leave open the possibility that the solar system is indeed different from other planetary systems.

Notes

1. Currently around 100 extrasolar planets are known which have been detected through the wobble of their host stars caused by the motion of the planets themselves.

2. The paper has recently been accepted by the Monthly Notices of the Royal Astronomical Society but no publication date has yet been set.


---------------------------------------------------------------------------
http://www.ras.org.uk/

The UK's leading team of planet-hunting astronomers, the Wide Angle Search for Planets (WASP), have announced the discovery of three new planets.

These extra-solar planets were seen to pass in front of, or transit, their host star. Studying such planets outside of our Solar System allows scientists to investigate how planetary systems form. WASP is the first team to detect planets in both the Northern and Southern Hemisphere using this technique.

Exoplanet expert Dr. Pierre Maxted comments “The planets are known as ‘hot-Jupiters’ as they are similar to Jupiter but are so close to their parent star that they orbit it in less than two days. This means that these planets have a surface temperature of nearly 2000°C and so are unlikely to host life. But finding these planets is important as these stars could also host much smaller planets similar to Earth, although detecting these worlds will be much more difficult”.

The planets orbit around stars similar to our Sun that are located at a distance of 850 light-years away from the Earth. Two are in the constellation of Phoenix visible only from the Southern hemisphere, while the third is in the Northern constellation of Lyra. All three stars are too faint to be seen with the naked eye, but are easily detectable with a small telescope.

Dr Coel Hellier, of Keele University, comments "When we see a transit we can deduce the size and mass of the planet and also what it is made of, so we can use these planets to study how solar systems form."

WASP-4 and WASP-5 are the first planets discovered by the WASP project's cameras in South Africa, and were confirmed by a collaboration with Swiss and French astronomers. "These two are now the brightest transiting planets in the Southern hemisphere" said Dr Hellier. WASP-3 is the third planet that the team has found in the North, using the SuperWASP camera sited in the Canary Islands.

Using data produced by SuperWASP’s cameras, which monitor up to 400,000 stars every minute, the new extra-solar planets were discovered as they were seen to pass in front of their host star.

Explaining the discovery, Dr Don Pollacco of Queen’s University, Belfast, Astrophysics Research Centre said: “We take pictures of the sky and measure the brightness of stars. If a planet is going around one of these stars and it happens to pass across the face of that star, our cameras will pick up the light from the star getting a little fainter.

“Discoveries such as these open up a whole new area of astronomy. Such transiting planets are important because they are the only ones that can have their mass and size measured directly. Astronomers can determine what they are made of and armed with this information we can begin to understand how these solar systems were formed.”

The WASP project is the most ambitious project in the world designed to discover large planets. Funding for the project comes from the UK Universities and the Science and Technology Facilities Council.

http://www.keele.ac.uk/

Life on a planet ruled by two suns might be a little complicated. Two sunrises, two sunsets. Twice the radiation field.


In a paper published in the December 2008 issue of Astronomy and Astrophysics, astronomer Joel Kastner and his team suggest that planets may easily form around certain types of twin (or “binary”) star systems. A disk of molecules discovered orbiting a pair of twin young suns in the constellation Sagittarius strongly suggests that many such binary systems also host planets.

“We think the molecular gas orbiting these two stars almost literally represents ‘smoking gun’ evidence of recent or possibly ongoing ‘giant’ (Jupiter-like) planet formation around the binary star system,” says Kastner, professor at Rochester Institute of Technology’s Chester F. Carlson Center for Imaging Science.

Kastner used the 30-meter radiotelescope operated by the Institut de Radio Astronomie Millimetrique (IRAM) to study radio molecular spectra emitted from the vicinity of the two stars in a binary system called V4046 Sgr, which lies about 210 light-years away from our solar system. (V4046 Sgr is the 4046th brightest variable-brightness star in the constellation Sagittarius.) The scientists found “in large abundance” raw materials for planet formation around the nearby stars, including circumstellar carbon monoxide and hydrogen cyanide, in the noxious molecular gas cloud.

The young stars, approximately 10 million years old, are close in proximity to each other—only 10 solar diameters apart—and orbit each other once every 2.5 days.

“In this case the stars are so close together, and the profile of the gas in terms of the types of molecules that are there is so much like the types of gaseous disks that we see around single stars, that it’s a real link between planets forming around single stars and planets forming around double stars,” Kastner says.

Planets that have just formed around young stars like the V4046 Sgr twins might leave leftover gas, a potential clue for astronomers who hunt planets.

Recently, direct imaging of planets orbiting the single stars Fomalhaut and HR 8799 irrefutably confirmed the existence of exosolar planets—those that orbit stars other than our Sun. In the spring, Kastner hopes to use IRAM to look for gas left over from the formation of the planets orbiting HR 8799.

Kastner hopes to compare the molecular profile in the gas remnants surrounding the single star (HR 8799) with the gas composition surrounding the dual star-system (V4046 Sgr).

Not a planet hunter himself, Kastner encourages other scientists to look closely at V4046 Sgr to see if planets are forming around them.

“We really don’t have any idea right now about what kinds of planets form around double stars or even if planets can form around double stars,” Kastner says. “It’s not something that’s established. It’s theoretically possible, but I’m not aware of a single observation yet of a planet orbiting a double star. I hope someone will go looking soon, if they haven’t already, around V4046 Sagittarius.”


http://www.rit.edu/

The International Astronomical Union (the IAU) has announced that the object previously known as 2003 EL61 is to be classified as the fifth dwarf planet in the Solar System and named Haumea.

The decision was made after discussions by members of the International Astronomical Union's Committee on Small Body Nomenclature (CSBN) and the IAU Working Group for Planetary System Nomenclature (WGPSN). This now means that the family of dwarf planets in the Solar System is up to five. They are now Ceres, Pluto, Haumea, Eris and Makemake.

The discovery of Haumea was announced in mid-2005, and the object was initially given the provisional designation of 2003 EL61. It is a bizarre object with a shape resembling a plump cigar. Its diameter is approximately the same as that of the dwarf planet Pluto; however, its odd shape means that it is much thinner. It is also known to be spinning very fast, making one rotation in about four hours. Some have suggested that this rapid rotation could be the reason Haumea came to look as it does - the dwarf planet has been drawn out and elongated by its swift spin.

Haumea sits among the trans-Neptunian objects, a vast ring of distant cold and rocky bodies in the outer Solar System. At this moment it is roughly 50 times the Sun-Earth distance from the Sun, but at its closest the elliptical orbit of Haumea brings it 35 times the Sun-Earth distance from our star.

Haumea is the name of the goddess of childbirth and fertility in Hawaiian mythology. The name is particularly apt as the goddess Haumea also represents the element of stone and observations of Haumea hint that, unusually, the dwarf planet is almost entirely composed of rock with a crust of pure ice.

Hawaiian mythology says that the goddess Haumea's children sprang from different parts of her body. The dwarf planet Haumea has a similar history, as it is joined in its orbit by two satellites that are thought to have been created by impacts with it in the past. During these impacts, parts of Haumea's icy surface were blasted off. The debris from these impacts is then thought to have gone onto form the two moons.

After their discovery, in 2005, the moons were also given provisional designations, but have now too been given names by the CSBN and the WGPSN. The first and largest moon is to be called Hi'iaka, after the Hawaiian goddess who is said to have been born from the mouth of Haumea and the patron goddess of the island of Hawai'i. The second moon of Haumea is named Namaka, a water spirit who is said to have been born from Haumea's body.


http://www.iau.org/

Saturn's ring shadows appear wrapped in a harmonious symphony with the planet in this color view from the Cassini spacecraft.

Saturn and its rings would nearly fill the space between Earth and the Moon. Yet, despite their great breadth, the rings are a few meters thick and, in some places, very translucent. This image shows a view through the C ring, which is closest to Saturn, and through the Cassini division, the 4,800-kilometer-wide gap (2,980-miles) that arcs across the top of the image and separates the optically thick B ring from the A ring. The part of the atmosphere seen through the gap appears darker and more bluish due to scattering at blue wavelengths by the cloud-free upper atmosphere.

The different colors in Saturn's atmosphere are due to particles whose composition is yet to be determined. This image was obtained with the Cassini spacecraft narrow angle camera on July 30, 2004, at a distance of 7.6 million kilometers (4.7 million miles) from Saturn.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

http://www.jpl.nasa.gov/

Imagine Captain Kirk being beamed back to the Starship Enterprise and two versions of the Star Trek hero arriving in the spacecraft's transporter room.


It happened 40 years ago in an episode of the TV science fiction classic, and now scientists at the University of York and colleagues in Japan have managed something strikingly similar in the laboratory - though no starship commander was involved.

The first experimental demonstration of quantum telecloning has been achieved by scientists at the University of Tokyo, the Japan Science and Technology Agency, and the University of York. The work is reported in the latest issue of Physical Review Letters. Telecloning combines cloning (or copying) with teleportation (i.e., disembodied transport).

The scientists have succeeded in making the first remote copies of beams of laser light, by combining quantum cloning with quantum teleportation into a single experimental step. Telecloning is more efficient than any combination of teleportation and local cloning because it relies on a new form of quantum entanglement - multipartite entanglement.

Professor Sam Braunstein, of the Department of Computer Science at York, said: "Quantum mechanics allows us to do things which we previously thought were impossible. In 1998, I was involved in an experiment in America which was one of the first for quantum teleportation in which we transmitted a beam of light without it crossing the physical medium in between.

"This new experiment is an extension of that work. Whether it will change the world for individuals or is just of use to governments or big companies is hard to say. Any new protocol is like a new-born baby and it has to develop, but we know this one could be used to tap cryptographic channels.

"Quantum cryptographic protocols are so secure that they can not only discover tapping but also where and how much information is leaking out. Now, using telecloning, the identity and location of the eavesdropper can be concealed."

Telecloning and teleportation may no longer be theories, but we are still a long way from teleporting people.

Professor Braunstein said: "What we know is that it would be incredibly difficult and from the perspective of today's technology, a completely outrageous thing. But in 100 years, who knows?"



http://www.york.ac.uk/

With the new movie ‘Star Trek’ opening in theaters across the nation, one thing movie goers will undoubtedly see is the Starship Enterprise racing across the galaxy at the speed of light. But can traveling at warp speed ever become a reality?


Two Baylor University physicists believe they have an idea that can turn traveling at the speed of light from science fiction to science, and their idea does not break any laws of physics.

Dr. Gerald Cleaver, associate professor of physics at Baylor, and Dr. Richard Obousy, a Baylor post-doctoral student, theorize that by manipulating the space-time dimensions around the spaceship with a massive amount of energy, it would create a “bubble” that could push the ship faster than the speed of light. To create this bubble, the Baylor physicists believe manipulating the 11-dimension would create dark energy. Cleaver said positive dark energy is responsible for speeding up the universe as time moves on, just like it did after the Big Bang, when the universe expanded faster than the speed of light.

“Think of it like a surfer riding a wave,” said Cleaver, who co-authored the paper with Obousy about the new method. “The ship would be pushed by the bubble and the bubble would be traveling faster than the speed of light.”

The method is based on the Alcubierre drive, which proposes expanding the fabric of space behind a ship into a bubble and shrinking space-time in front of the ship. The ship would not actually move, rather the ship would sit in between the expanding and shrinking space-time dimensions. Since space would move around the ship, the theory does not violate Einstein’s Theory of Relativity, which states that it would take an infinite amount of energy to accelerate an object faster than the speed of light.

String theory suggests the universe is made up of multiple dimensions. Height, width and length are three dimensions, and time is the fourth dimension. Scientists believe that there are a total of 10 dimensions, with six other dimensions that we can not yet identify. A new theory, called M-theory, takes string theory one step farther and states that the “strings” actually vibrate in an 11-dimensional space. It is this 11th dimension that the Baylor researchers believe could help propel a ship faster than the speed of light.

The Baylor physicists estimate that the amount of energy needed to influence the extra dimensions is equivalent to the entire mass of Jupiter being converted into energy.

“That is an enormous amount of energy,” Cleaver said. “We are still a very long ways off before we could create something to harness that type of energy.”

http://www.baylor.edu/

The first robotic mission to return samples to Earth from Mars took a further step toward realisation with the recent publication of a mission design report by the iMARS Working Group. The report defines key elements of the future internationally-funded mission involving the cooperation of ESA, NASA and other national agencies.


iMARS, which stands for the International Mars Architecture for the Return of Samples, is a committee of the International Mars Exploration Working Group made up of scientists, engineers, strategic planners, and managers. The report, which comes after months of deliberation, outlines the scientific and engineering requirements of such an international mission to be undertaken in the timeframe 2020-2022.

The Mars Sample Return mission is an essential step with respect to future exploration goals and the prospect of establishing a future human mission to Mars. Returned samples will increase the knowledge of the properties of Martian soil and contribute significantly to answering questions about the possibility of life on the Red Planet. This mission will improve our understanding of the Mars environment to support planning for the future human exploration.

The iMARS report outlines the mission’s scientific objectives including the types and quantities of samples to be returned from Mars; the different mission elements (launchers, spacecraft, Mars lander, a rover and a Mars ascent vehicle) and ground processing facilities necessary to contain and analyse the received samples in a protected environment. A preliminary timeline for the mission and approximate budget has also been defined.

“Exploration is gaining momentum year by year, as is the experience and knowledge gained by ESA and its international partners in this area” said Bruno Gardini ESA’s Exploration Programme Manager in the Directorate of Human Spaceflight and iMARS study leader. “The information we gain from current Mars missions and from the ISS provide a basis not only for future robotic missions but also a stepping stone for the human exploration missions.”


http://www.esa.int/esaCP/index.html

In the last year space agencies in the United States, Europe, China, Japan and India have announced their intention to resume human exploration of the Solar system, beginning with the Moon and perhaps ultimately moving on to Mars. But travel beyond the immediate vicinity of the Earth carries significant risks for astronauts, not the least of which is the exposure to sometimes high levels of radiation. Now a team of scientists at the Rutherford Appleton Laboratory are set to construct an experimental magnetic shield that would protect explorers in their journeys between the planets. Dr Ruth Bamford presented this idea at the Royal Astronomical Society National Astronomy Meeting in Preston.

Cosmic rays and radiation from the Sun itself can cause acute radiation sickness in astronauts and even death. Between 1968 and 1973, the Apollo astronauts going to the moon were only in space for about 10 days at a time and were simply lucky not to have been in space during a major eruption on the sun that would have flooded their spacecraft with deadly radiation. In retrospect Neil Armstrong’s ‘one small step for Man’ would have looked very different if it had.

On the International Space Station there is a special thick-walled room to which the astronauts have had to retreat during times of increased solar radiation. However on longer missions the astronauts cannot live within shielded rooms, since such shielding would add significantly to the mass of the spacecraft, making them much more expensive and difficult to launch. It is also now known that the ‘drip-drip’ of even lower levels of radiation can be as dangerous as acute bursts from the sun.

On the surface of the Earth we are protected from radiation by the thick layers of the atmosphere. And the terrestrial magnetic field extends far into space, acting as a natural ‘force field’ to further protect our planet and deflecting the worst of the energetic particles from the Sun by creating a ‘plasma barrier’.

Now scientists at the Rutherford Appleton Laboratory in Oxfordshire plan to mimic nature. They will build a miniature magnetosphere in a laboratory to see if a deflector shield can be used to protect humans living on space craft and in bases on the Moon or Mars.

In order to work, an artificial mini-magnetosphere on a space craft will need to utilise many cutting edge technologies, such as superconductors and the magnetic confinement techniques used in nuclear fusion.

Thus science is following science fiction once again. The writers of Star Trek realised that any space craft containing humans would need protection from the hazardous effects of cosmic radiation. They envisioned a ‘deflector shield’ spreading out from the Starship Enterprise that the radiation would bounce off. These experiments will help to establish whether this idea could one day become a practical reality.


http://www.ras.org.uk/

A team of astronomers, led by Dr. Bo Wang from the Yunnan Observatory of the Chinese Academy of Sciences, has developed a new model which explains the formation of the most youthful type Ia supernovae. In a paper published in Monthly Notices of the Royal Astronomical Society, the researchers show how the transfer of material from a ‘helium star’ to a compact white dwarf companion causes these cataclysmic events to take place early on in the life of the galaxy they formed in.


Most type Ia supernovae are believed to occur when a white dwarf (the superdense remnant that is the end state of stars like the Sun) draws matter from a companion star orbiting close by. When the white dwarf mass exceeds the so-called Chandrasekhar limit of 1.4 times the mass of the Sun, it eventually collapses and within a few seconds undergoes a runaway nuclear fusion reaction, exploding and releasing a vast amount of energy as a type Ia supernova. Due to their high and remarkably consistent luminosities, astronomers use these events as ‘distance indicators’ to measure the distances to other galaxies and constrain our ideas about the Universe.

Scientists have confirmed more and more type Ia supernovae, and found that about half of them explode less than 100 million years after their host galaxy’s main star formation period. But previous models for these systems did not predict that they could be this young so Dr. Wang and his team set out to solve this mystery.

Employing a stellar evolution computer code, they performed calculations for about 2600 binary systems consisting of a white dwarf and a helium star, a hot blue star which has a spectrum dominated by emission from helium. They found that if the gravitational field of the white dwarf pulls material from a helium star and increases its mass beyond the Chandrasekhar limit, it will explode as a type Ia supernova within 100 million years of its formation.

The team now plans to model the properties of the companion helium stars at the moment of the supernova explosions, which could be verified by future observations from the Large sky Area Multi-Object fiber Spectral Telescope (LAMOST).

Team member Prof. Dr. Zhanwen Han comments, “Type Ia supernovae are a key tool to determine the scale of the Universe so we need to be sure of their properties. Our work shows that they can take place early on in the life of the galaxy they reside in.”


http://www.ras.org.uk/

Observations of the white dwarf star, Sirius B, made with NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite give astronomers firm new evidence that mathematical models widely used to predict white dwarf star mass and radius are correct.


Jay B. Holberg of the University of Arizona Lunar and Planetary Laboratory is presenting the result today at the American Astronomical Society in San Diego.

The FUSE result is important because Sirius B is one of the few stars that astronomers have to test their ideas on the relationship between mass and radius for white dwarf stars. White dwarf stars are small but astonishingly dense stars. Sirius B is the size of the Earth and as massive as the sun.

Theory that describes how white dwarf stars can exist emerged in the early 1930s, when Subramanyan Chandrasekhar – or Chandra, as he was known – calculated the limit to a white dwarf's mass by applying Einstein's theory of special relativity. It was one of the first applications of quantum mechanics to large physical systems in the sky.

No white dwarf star could be more than 1.4 times as massive as the sun or it will collapse, Chandra predicted.

"Chandra was the first person to lay out the essential details of how white dwarfs sustain themselves, and it is very, very different from the sun or any other stars," Holberg said.

Unlike most white dwarfs, Sirius B is part of a binary system, and astronomers can determine the mass of stars in a binary system.

"Having a binary system – when two stars orbit one another - is virtually the only way you can fundamentally measure the mass of a star," Holberg said. "You observe their orbits, get the period, know how far away they are, and you can find the sum of the two star masses. If you can time the orbits and know how far apart the stars are, you can determine the individual star masses. That's the most accurate way, the acceptable way to determine star masses.

"But this star has always been devilishly difficult to observe," Holberg said. The primary star in the system, Sirius A, is 8 light years from Earth and has twice the mass of the sun. It is the brightest star in the night sky, visible below Orion. Sirius B is 10,000 times dimmer than Sirius A. Astronomers can’t even see the white dwarf companion when it comes closest to the primary star during its 50-year, very elongated orbit around Sirius A.

For the post several years, Holberg and colleagues have observed Sirius B with the Voyager and Extreme Ultraviolet Explorer spacecrafts. They have refined the star's temperature and gravity - gravity being the gravitational field at the surface of the star - to refine estimates of its mass and radius.

"The methods we're using are spectroscopic. They infer the mass from synthetic models that we produce from measurements of temperature and gravity, the only two parameters of matter for a white dwarf."

Holberg and his colleagues published the best determination of Sirius B's mass-radius relationship in 1998, but that was "still far from definitive," Holberg said. "That is, the uncertainties are so large, that while these studies define the basic relationship, they don’t tell you lots of details we need to know about these stars."

The FUSE observations gave Holberg and his colleagues better spectral data on Sirius B's gravitational field and temperature needed to calculate mass. "And this is a very clean spectrum. We rolled the FUSE spacecraft to keep Sirius A from contaminating the spectrum, and we succeeded very well.

"The mathematical model very well predicts our results on the gravitational field, temperature and brightness of this white dwarf star," Holberg said. "That helps us determine the radius of the star. What we really want to do is determine mass and radius to within one percent. By verifying the Chandrasekhar limit, you put a great deal of astrophysics on much firmer footing," he added.

"Astronomy has reached the level where you can make very definitive comparisons between the models and the observations. And it looks like we are going to come out to what we expected," Holberg said.


http://www.arizona.edu/

An international team, led by astronomers at the University of Hertfordshire in the UK, have discovered one of the coolest sub-stellar bodies ever found outside our own solar system, orbiting the red dwarf star Wolf 940, some 40 light years from Earth. Dr Ben Burningham of the University of Hertfordshire will present this discovery on Monday 20th April at the European Week of Astronomy and Space Science conference.
"Although it has a temperature of 300 degrees Celsius, almost hot enough to melt lead, temperature is relative when you study this sort of thing, and this object is cool by stellar standards. In fact this is the first time we've been able to study an object as cool as this in such detail", says Dr Burningham, "the fact that it is orbiting a star makes it extra special".

The object is thought to have formed like a star, but has ended up looking more like Jupiter. It is roughly the same size, despite being between 20 and 30 times as heavy, and when the infrared spectral "fingerprints" of the two objects are compared, their resemblance is striking.

The new object orbits its star at about 440 times the distance at which the Earth orbits the sun. At such a wide distance, it takes about 18,000 years to complete a single orbit.

Too small to be stars, so-called "brown dwarfs" have masses lower than stars but larger than gas giant planets like Jupiter. Due to their low temperature these objects are very faint in visible light, and are detected by their glow at infrared wavelengths.

Modelling the atmospheres of cool brown dwarfs is a complex task, but it is key to understanding what we see when we look at planets that orbit other stars. Models of emitted light from such objects, which are dominated by absorption due to water and methane gas, are sensitive to assumptions about their age and chemical make-up.

In most cases astronomers don't initially know much about the age and composition of brown dwarfs and this can make it hard to tell where the models are right, and where they are going wrong.

"What's so exciting in this case, is that we can use what we know about the primary star to find out about the properties of the brown dwarf, and that makes it an extremely useful find", explains Dr Burningham, "you can think of it as a Rosetta Stone for decrypting what the light from such cool objects is telling us".

The object has been named Wolf 940B, after the red dwarf star that it orbits, which was first catalogued by the pioneering German astronomer Max Wolf ninety years ago.

"Red dwarfs are the most populous stars in the Galaxy, and systems like this may be more common than we know" says Dr David Pinfield of the University of Hertfordshire, "As the generation of ongoing large scale surveys continues, we may discover a pack of Wolf-940B-like objects in our solar back yard."

Wolf 940B was initially discovered as part of a major infrared sky survey - the UKIRT Infrared Deep Sky Survey (UKIDSS) which is being carried out using the United Kingdom Infrared Telescope (UKIRT) on Mauna Kea in Hawaii.

The object was found as part of a wider effort to find the coolest and least luminous bodies in our local Galactic neighbourhood, but it was then found to be a companion to the nearby red dwarf Wolf 940 through its common motion across the sky. The data used to confirm the discovery were obtained using telescopes in Chile, the Canary Islands and Hawaii.

Its temperature was then confirmed using data from the Gemini-North telescope on Mauna Kea. The team's findings will soon be published in the Monthly Notices of the Royal Astronomical Society.

Following its discovery with ground based telescopes, Wolf 940B, has since been observed by the NASA's Spitzer Space Telescope, and the findings from those observations will be published later this year.

"This object is going to continue to provide insights into the processes of cool brown dwarf, and warm planetary atmospheres for some time to come", says Dr Sandy Leggett, of the Gemini Observatory, "finding it was just the first step".


http://www.ras.org.uk/

Astronomers have found three brown dwarfs with estimated masses of less than 10 times that of Jupiter, making them among the youngest and lowest mass sub-stellar objects detected in the solar neighbourhood to date.

The observations were made by a team of astronomers working at the Laboratoire d'Astrophysique de l'Observatoire de Grenoble (LAOG), France, using the Canada-France-Hawaii Telescope (CFHT). Andrew Burgess will be presenting the discovery at the European Week of Astronomy and Space Science at the University of Hertfordshire, Hatfield, on Wednesday 22nd April.

The dwarfs were found in a star forming region named IC 348, which lies almost 1000 light years from the Solar System towards the constellation of Perseus. This cluster is approximately 3 million years old – extremely young compared to our 4.5 billion year old Sun – which makes it a good location in order to search for the lowest mass brown dwarfs. The dwarfs are isolated in space, which means that they are not orbiting a star, although they are gravitationally bound to IC 348. Their atmospheres all show evidence of methane absorption which was used to select and identify these young objects.

"There has been some controversy about identifying young, low mass brown dwarfs in this region. An object of a similar mass was discovered in 2002, but some groups have argued that it is an older, cooler brown dwarf in the foreground coinciding with the line of sight. The fact that we have detected three candidate low-mass dwarfs towards IC 348 supports the finding that these really are very young objects," said Burgess.

The team set out to find a population of these brown dwarfs in order to help theoreticians develop more accurate models for the distribution of mass in a newly-formed population, from high mass stars to brown dwarfs, which is needed to test current star formation theories. The discovery of the dwarfs in IC 348 has allowed them to set new limits on the lowest mass objects.

"Finding three candidate low-mass dwarfs towards IC 348 backs up predictions for how many low-mass objects develop in a new population of stars. Brown dwarfs cool with age and current models estimate that their surfaces are approximately 900-1000 degrees Kelvin (about 600-700 degrees Celsius). That’s extremely cool for objects that have just formed, which implies that they have the lowest masses of any of this type of object that we’ve seen to date," said Burgess.


http://www.ras.org.uk/

In the hit 1998 movie Armageddon, Bruce Willis and Ben Affleck blew up an asteroid to save the world. While the film was science fiction, the chances of an asteroid hitting the Earth one day are very real ― and blowing up an asteroid in real life, says a Tel Aviv University researcher, will be more complicated than in the movies.
Astrophysicists agree that the best method for avoiding a catastrophic collision would be to change the path of the asteroid heading toward our planet. “For that to work, we need to be able to predict what would happen if we attempt an explosion,” says Tel Aviv University doctoral student David Polishook, who is studying asteroids with his supervisor Dr. Noah Brosch at the Department of Geophysics and Planetary Sciences.

Polishook and Brosch are among the few scientists in the world researching the structure and composition of asteroids a critical first step in learning how to destroy them before they reach the Earth’s atmosphere. Their research could prevent catastrophe: blowing up an asteroid may create many equally dangerous smaller asteroids of about 100 meters each in diameter ― twice the size of the asteroid that created the famous Arizona crater.

Looking on the Bright Sides

“The information we are investigating can have a tremendous impact on future plans to alter the course of asteroids on a collision course with Earth,” says Polishook. “Science needs to know whether asteroids are solid pieces of rock or piles of gravel, what forces are holding them together, and how they will break apart if bombed.”

By observing the waxing and waning brightness of far-away asteroids, Polishook is able to examine the shape, spin period and surface composition of these flying rocks. “This is a good way of evaluating what asteroids are made of,” says Polishook, who takes measurements on an almost daily basis at Tel Aviv University's Wise Observatory.

As part of their observations, the researchers used the fact that small asteroids change their rotation rate, accelerating or slowing down during short periods, as often as every 100,000 years. Compared to the age of the solar system 4.5 billion years that is an extremely fast change, says Polishook.

The most recent results of their research were presented at the 2008 meeting of Asteroids, Comets and Meteors, sponsored by the Johns Hopkins University Applied Physics Laboratory in Baltimore.

Size Matters

An asteroid’s rotation and acceleration are influenced by sunlight the “YORP Effect.” If the YORP effect causes an asteroid to rotate faster than one revolution in 2.2 hours, it will break apart.

To understand how the YORP Effect works on asteroids, Tel Aviv University researchers examined several variables relating to these asteroids, including size and location. They concluded that size is the most important factor in determining how an asteroid’s rotation rate accelerates according to the YORP Effect.

“We think this adds an important clue to how asteroids will behave should a space agency need to knock one off-course to prevent a collision with earth,” Polishook notes.


http://www.aftau.org/site/PageServer?pagename=home_page

A new study published in Nature this week reveals that asteroid surfaces age and redden much faster than previously thought — in less than a million years, the blink of an eye for an asteroid. This study has finally confirmed that the solar wind is the most likely cause of very rapid space weathering in asteroids.
This fundamental result will help astronomers relate the appearance of an asteroid to its actual history and identify any after effects of a catastrophic impact with another asteroid.

“Asteroids seem to get a ‘sun tan’ very quickly,” says lead author Pierre Vernazza. “But not, as for people, from an overdose of the Sun’s ultraviolet radiation, but from the effects of its powerful wind.”

It has long been known that asteroid surfaces alter in appearance with time — the observed asteroids are much redder than the interior of meteorites found on Earth [1] — but the actual processes of this “space weathering” and the timescales involved were controversial.

Thanks to observations of different families of asteroids [2] using ESO’s New Technology Telescope at La Silla and the Very Large Telescope at Paranal, as well as telescopes in Spain and Hawaii, Vernazza’s team have now solved the puzzle.

When two asteroids collide, they create a family of fragments with “fresh” surfaces. The astronomers found that these newly exposed surfaces are quickly altered and change colour in less than a million years — a very short time compared to the age of the Solar System.

“The charged, fast moving particles in the solar wind damage the asteroid’s surface at an amazing rate [3]”, says Vernazza. Unlike human skin, which is damaged and aged by repeated overexposure to sunlight, it is, perhaps rather surprisingly, the first moments of exposure (on the timescale considered) — the first million years — that causes most of the aging in asteroids.

By studying different families of asteroids, the team has also shown that an asteroid’s surface composition is an important factor in how red its surface can become. After the first million years, the surface “tans” much more slowly. At that stage, the colour depends more on composition than on age. Moreover, the observations reveal that collisions cannot be the main mechanism behind the high proportion of “fresh” surfaces seen among near-Earth asteroids. Instead, these “fresh-looking” surfaces may be the results of planetary encounters, where the tug of a planet has “shaken” the asteroid, exposing unaltered material.

Thanks to these results, astronomers will now be able to understand better how the surface of an asteroid — which often is the only thing we can observe — reflects its history.

Notes

[1] Meteorites are small fragments of asteroids that fall on Earth. While a meteorite enters the Earth's atmosphere its surface can melt and be partially charred by the intense heat. Nevertheless, the meteorite interior remains unaffected, and can be studied in a laboratory, providing a wealth of information on the nature and composition of asteroids.

[2] An asteroid family is a group of asteroids that are on similar orbits around the Sun. The members of a given family are believed to be the fragments of a larger asteroid that was destroyed during a collision.

[3] The surface of an asteroid is affected by the highly energetic particles forming the solar wind. These particles partially destroy the molecules and crystals on the surface, re-arranging them in other combinations. Over time, these changes give formation of a thin crust or irradiated material with distinct colours and properties.

http://www.nature.com/nature/journal/v458/n7241/full/nature07956.html