A team of scientists led by Carnegie’s Lin Wang has observed a new form of very hard carbon clusters, which are unusual in their mix of crystalline and disordered structure. The material is capable of indenting diamond. This finding has potential applications for a range of mechanical, electronic, and electrochemical uses. The work is published in Science on August 17. (from carnegiescience.edu)

Jaw structures suggest that at least three homo species once roamed the African plains. (from Nature.com)

Fossilized skulls show that at least three distinct species belonging to the genus homo existed between 1.7 million and 2 million years ago, settling a long-standing debate in palaeoanthropology.
A study published this week in Nature focuses on homo rudolfensis, a hominin with a relatively flat face, which was first identified from a single large skull in 1972. Several other big-skulled fossils have been attributed to the species since then, but none has included both a face and a lower jaw. This has been problematic: in palaeoanthropology, faces and jaws function like fingerprints for identifying a specimen as a particular species (which is indicated by the second word in a Linnaean title, such as ‘rudolfensis’), as opposed to the broader grouping of genus (the first word, as in ‘ homo’).

Without complete skulls, it has been difficult to reach a consensus on whether specimens attributed to H. rudolfensis are genuinely members of a distinct species, or actually belong to other homo species that lived around the same time, such as homo habilis or  homo erectus. Understanding how many different homo species there were, and whether they lived concurrently, would help to determine whether the history of the human lineage saw fierce competition between multiple hominins, or a steady succession from one species to another.
But the latest result has dissipated much of this uncertainty. It concerns three fossils — two lower jaws and a juvenile’s lower face — that were found in a desert area called Koobi Fora in northern Kenya. The team that pulled them out of the ground, led by Meave Leakey, a palaeontologist at the Turkana Basin Institute in Nairobi, describes how the dental arcade, the arch created by the teeth at the front of the mouth, is nearly rectangular, just like the palate structure of the 1972 skull. By contrast, the average modern human mouth has a curved dental arcade.
Further evidence comes from the juvenile’s face, which tellingly has cheek bones joining the palate quite far forward. “It was such an extended excitement as the juvenile face slowly emerged from the encasing rock, and its similarity to the 1972 specimen became so striking,” recalls Leakey.

PASADENA, Calif. — NASA’s most advanced Mars rover Curiosity has landed on the Red Planet. The one-ton rover, hanging by ropes from a rocket backpack, touched down onto Mars Sunday to end a 36-week flight and begin a two-year investigation. (from nasa.gov)

The Mars Science Laboratory (MSL) spacecraft that carried Curiosity succeeded in every step of the most complex landing ever attempted on Mars, including the final severing of the bridle cords and flyaway maneuver of the rocket backpack.

“Today, the wheels of Curiosity have begun to blaze the trail for human footprints on Mars. Curiosity, the most sophisticated rover ever built, is now on the surface of the Red Planet, where it will seek to answer age-old questions about whether life ever existed on Mars — or if the planet can sustain life in the future,” said NASA Administrator Charles Bolden. “This is an amazing achievement, made possible by a team of scientists and engineers from around the world and led by the extraordinary men and women of NASA and our Jet Propulsion Laboratory. President Obama has laid out a bold vision for sending humans to Mars in the mid-2030’s, and today’s landing marks a significant step toward achieving this goal.”

Curiosity landed at 10:32 p.m. Aug. 5, PDT, (1:32 a.m. EDT Aug. 6) near the foot of a mountain three miles tall and 96 miles in diameter inside Gale Crater. During a nearly two-year prime mission, the rover will investigate whether the region ever offered conditions favorable for microbial life.

“The Seven Minutes of Terror has turned into the Seven Minutes of Triumph,” said NASA Associate Administrator for Science John Grunsfeld. “My immense joy in the success of this mission is matched only by overwhelming pride I feel for the women and men of the mission’s team.”

Curiosity returned its first view of Mars, a wide-angle scene of rocky ground near the front of the rover. More images are anticipated in the next several days as the mission blends observations of the landing site with activities to configure the rover for work and check the performance of its instruments and mechanisms.

“Our Curiosity is talking to us from the surface of Mars,” said MSL Project Manager Peter Theisinger of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The landing takes us past the most hazardous moments for this project, and begins a new and exciting mission to pursue its scientific objectives.”

Confirmation of Curiosity’s successful landing came in communications relayed by NASA’s Mars Odyssey orbiter and received by the Canberra, Australia, antenna station of NASA’s Deep Space Network.

Curiosity carries 10 science instruments with a total mass 15 times as large as the science payloads on the Mars rovers Spirit and Opportunity. Some of the tools are the first of their kind on Mars, such as a laser-firing instrument for checking elemental composition of rocks from a distance. The rover will use a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, then sieve and parcel out these samples into analytical laboratory instruments inside the rover.

To handle this science toolkit, Curiosity is twice as long and five times as heavy as Spirit or Opportunity. The Gale Crater landing site places the rover within driving distance of layers of the crater’s interior mountain. Observations from orbit have identified clay and sulfate minerals in the lower layers, indicating a wet history.

The mission is managed by JPL for NASA’s Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. JPL is a division of the California Institute of Technology in Pasadena.

For more information on the mission, visit: http://www.nasa.gov/mars and http://marsprogram.jpl.nasa.gov/msl .

Follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity And http://www.twitter.com/marscuriosity .

Officials at the Russian Federal Space Agency(RosCosmos) announce that the Progress 48 space capsule reached the International Space Station(ISS) earlier today. What is so special about this particular resupply mission is that the spacecraft docked to the station less than six hours after launch. (from google)

This was the first flight that attempted a new launch and navigation procedure. Usually, Russian Progress and Soyuz capsules take up to two days to track down the orbital lab, before they dock.

Progress 48 launched aboard a Soyuz delivery system from the Baikonur Cosmodrome, in Kazakhstan, at 3:35 pm EDT (1935 GMT), on Thursday, August 1. Its automated docking system saw it latching on the ISS Pirs module at 9:19 pm EDT (0119 GMT), on August 2, less than six hours later.

The successful test of the new flight approach will be very appreciated by astronauts. Currently, all crew rotations aboard the station are handled through Russian Soyuz capsule. These vehicles carry three astronauts at one time, who spend 48 hours crammed up in a tiny space.

RosCosmos orbital engineers have developed the new paths for the capsules so that the flight is made as comfortable as possible for the crew. It was first tested on Progress 48 because this is an unmanned, resupply flight.

The cargo capsule carries food, water, scientific experiments, propellant for the ISS thrusters, and personal items for the six astronauts making up the Expedition 32 crew, Space reports.

The Russians are “looking to eventually take this into the Soyuz phase. If you can get the crew to orbit in six hours and onboard the International Space Station, that could be a tremendous benefit over the two-plus days it takes today,” NASA ISS operations and integration manager, Dan Harman, said.

In addition to extra comfort for the crew, the capsules themselves could carry more cargo, since the amount of fuel currently needed for two days of travel could be eliminated.

“The quicker rendezvous that you have, the less consumables you would need for the first day, and the better crew comfort in a small capsule,” ISS flight director Chris Edelen added.

The official says that same-day launch and docking procedures are very complex, and require tremendous amounts of calculations. Both the launching spacecraft and the ISS have to be in very precise positions when liftoff occurs.

Progress 48 is scheduled to remain docked to the ISS until December. After undocking, it will be purposefully destroyed in the upper atmosphere.

Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when commercial products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of ‘relativistic’ condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top experiments. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

by A. K. GEIM AND K. S. NOVOSELOV from Nature (truncated)

Graphene is the name given to a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite. Theoretically, graphene (or ‘2D graphite’) has been studied for sixty years, and is widely used for describing properties of variouscarbon-based materials. Forty years later, it was realized that graphene also provides an excellent condensed-matter analogue of (2+1)-dimensional quantum electrodynamics, which propelled graphene into a thriving theoretical toy model. On the other hand, although known as an integral part of 3D materials, graphene was presumed not to exist in the free state, being described as an ‘academic’ material and was believed to be unstable with respect to the formation of curved structures such as soot, fullerenes and nanotubes. Suddenly, the vintage model turned into reality, when free-standing  graphene was unexpectedly found three years ago — and especially when the follow-up experiments confirmed that its charge carriers were indeed massless Dirac fermions. So, the graphene ‘gold rush’ has begun.

In the absence of quality graphene wafers, most experimental groups are currently using samples obtained by micromechanical cleavage of bulk graphite, the same technique that allowed the isolation of graphene for the first time. After fine-tuning, the technique now provides high-quality graphene crystallites up to 100 μm in size, which is sufficient for most research purposes. Superficially, the technique looks no more sophisticated than drawing with a piece of graphite8 or its repeated peeling with adhesive tape until the thinnest flakes are found. A similar approach was tried by other groups but only graphite flakes 20 to 100 layers thick were found.

At low temperatures, all metallic systems with high resistivity should inevitably exhibit large quantum-interference (localization) magnetoresistance, eventually leading to the metal–insulator transition at σ ≈ e2/h. Such behaviour was thought to be universal,
but it was found missing in graphene.

Despite the reigning optimism about graphene-based electronics, ‘graphenium’ microprocessors are unlikely to appear for the next 20 years. In the meantime, many other graphene-based applications are likely to come of age. In this respect, clear parallels with nanotubes allow a highly educated guess of what to expect soon. The most immediate application for graphene is probably its use in composite materials. Indeed, it has been demonstrated that a graphene powder of uncoagulated micrometre-size crystallites can be produced in a way scaleable to mass production. This allows conductive plastics at less than one volume percent filling, which in combination with low production costs makes graphene-based composite materials attractive for a variety of uses. However, it seems doubtful that such composites can match the mechanical strength of their nanotube counterparts because of much stronger entanglement in the latter case. Another enticing possibility is the use of graphene powder in electric batteries that are already one of the main markets for graphite. An ultimately large surface-to-volume ratio and high conductivity provided by graphene powder can lead to improvements in the efficiency of batteries, taking over from the carbon nanofibres used
in modern batteries. Carbon nanotubes have also been considered for this application but graphene powder has an important advantage of being cheap to produce. One of the most promising applications for nanotubes is field emitters, and although there have been no reports yet about such use of graphene, thin graphite flakes were used in plasma displays (commercial prototypes) long before graphene was isolated, and many patents were filed on this subject. It is likely that graphene powder can offer even more superior emitting properties. Carbon nanotubes have been reported to be an excellent material for solid-state gas sensors but graphene offers clear advantages in this particular direction. Spin-valve and superconducting fieldeffect transistors are also obvious research targets, and recent reports describing a hysteretic  magnetoresistance and substantial bipolar supercurrents prove graphene’s major potential for these applications. An extremely weak spin-orbit coupling and the absence of hyperfine interaction in 12C-graphene make it an excellent if not ideal material for making spin qubits. This guarantees graphene-based quantum computation to become an active research area. Finally, we cannot omit mentioning hydrogen storage, which has been an active but controversial subject for nanotubes. It has already been suggested that graphene is capable of absorbing a large amount of hydrogen, and experimental efforts in this direction are duly expected.

It has been just a few years since graphene was first reported, and despite remarkably rapid progress, only the very tip of the iceberg has been uncovered so far. Because of the short timescale, most experimental groups working now on graphene have not published even a single paper on the subject, which has been a truly frustrating experience for theorists. This is to say that, at this time, no review can possibly be complete. Nevertheless, the research directions explained here should persuade even die-hard
sceptics that graphene is not a fleeting fashion but is here to stay, bringing up both more exciting physics, and perhaps even wideranging applications.