Oldest Known Ocean Crust Found on Greenland

Scientists have discovered a 3.8-billion-year-old rock formation in Greenland that they say is the earliest example of oceanic crust ever to be discovered. The find suggests that some processes of plate tectonics—the slow but steady drifting and collision of giant pieces of Earth's outer shell—may have begun much earlier than previously suspected.

Hidden in plain sight among an oft-studied cluster of ancient rocks, the Greenland formation contains a telltale structure known as a sheeted dike complex.Because such a complex can form only during continuous crustal spreading, it identifies the Greenland rocks as ophiolites, or pieces of ocean crust that were later stranded on land. During a process called seafloor spreading, new crust is constantly created by molten rock rising to fill ever widening cracks in the ocean floor. Ophiolites can be formed when this oceanic crust is caught up in a collision of continents, forcing some of the material onto the surface. "The smoking gun here is the sheeted dike complex and hence the most important component for recognizing these rocks as an ophiolite," said study leader Harald Furnes, a professor of earth science at the University of Bergen in Norway. "The rock sequence we describe from southwest Greenland we recognized as representing the oldest ophiolite on Earth, and hence the oldest oceanic crust formed by seafloor spreading," he added. The finding, which appears in tomorrow's issue of the journal Science, may have enormous consequences for understanding the early history of the planet—and its most primitive life. Many experts suspect the first organisms originated at or near the hydrothermal vents responsible for seafloor spreading, because they may have provided the energy for chemical reactions and helped concentrate vital nutrients.Earth-Shaking Controversy According to the theory of plate tectonics, Earth's upper surface is a jigsaw puzzle of rigid plates that slowly drift over a layer of hot fluidlike rock. At many places these plates collide violently, causing volcanic activity and triggering massive earthquakes as one plate is subducted, or pushed beneath the other.

Stone Age Massacre Revealed in British Tombs

Gruesome evidence found in ancient burial chambers reveals a period of violence and instability in Stone Age Britain, according to archaeologists.

Signs of bloody massacres and fractured societies are emerging from research that used new dating techniques to age prehistoric skeletons and burial sites in southern England. The sites include Wayland's Smithy in Oxfordshire, where the remains of 14 people show evidence of an ancient massacre, according to a team led by the U.K. government body English Heritage. Eleven of the skeletons were of adult males, at least three of whom were likely killed by arrows, the team reported. One man still had the tip of a flint arrowhead embedded in his pelvic bone. Two of the bodies appeared to have been scavenged and partially dismembered by wolves or dogs before burial. Analysis using radiocarbon dating and other archaeological clues placed the age of all the bones at around 3570 B.C., some 800 years before Stonehenge was built in the same region. The burials were previously thought to have spanned several centuries. "We can now say they were put in the tomb at pretty much the same time," said Alex Bayliss, an archaeologist with English Heritage."Three of them were almost certainly killed by arrowheads found with the remains in the tomb," Bayliss said. "It's quite possible that there was some act of collective violence. "It's as if there was a cattle raid or something," she added.

news taken from national geographic(nationalgeographic.com)

In the latest bid to rocket tourists into orbit, the secretive Blue Origin unveils a flying pod.

A mere three years after Burt Rutan’s SpaceShipOne skimmed the edge of space to capture the $10-million Ansari X Prize, more than half a dozen companies are furiously building and testing spacecraft designed to take paying passengers on suborbital journeys and beyond. Five states, including California, Oklahoma, Florida, Virginia and Alaska, now hold government licenses for commercial spaceports—and the Federal Aviation Administration is already working to create new protocols so air-traffic controllers will know how to route old-fashioned commercial flights clear of busy spaceport traffic. “The giggle factor is gone,” says Taber MacCallum, CEO of Tucson, Arizona-based Paragon Space Development Corp., one of a number of firms angling to supply future spaceliners with everything from spacesuits to rocket parts. In January, Amazon.com founder Jeff Bezos grabbed headlines when he revealed that his secretive seven-year-old rocket-science side venture, Blue Origin, had successfully tested a vehicle dubbed Goddard. The craft, which launches and lands vertically, is a significant step toward the billionaire’s plans for flying sightseers to low Earth orbit and beyond. A video posted on the company’s Web site reveals a gumdrop-shaped capsule whooshing 285 feet above the West Texas scrub and, cushioned by the thrust of nine rocket nozzles, gently descending onto stubby legs. Bezos wouldn’t comment publicly, but a recent 223-page Federal Aviation Administration filing by his rocket scientists reveals more clues: This year, engineers will attempt to push Goddard, which uses concentrated hydrogen peroxide as a propellant, to an altitude of 2,000 feet.
By 2010, Blue Origin hopes to launch weekly suborbital passenger flights in a ship called New Shepard (as in Alan Shepard, the first American in space). The 50-foot-tall vehicle will ferry at least three passengers to 62 miles for a few moments of zero gravity at the edge of space, and land using retrorockets and a parachute.
Meanwhile Richard Branson’s company Virgin Galactic aims to beat Blue Origin to the launchpad and will test a craft dubbed the VSS Enterprise (yes, Spock, that one) next year, with commercial flights as soon as 2009. Designed by Rutan and modeled on SpaceShipOne, the 60-foot-long spaceliner will carry six passengers and two pilots. Another favored contender in the suborbital space race is Rocketplane Kistler in Oklahoma City. Its craft, the Rocketplane XP, is based on a heavily modified Learjet 25 fuselage, with rocket engines delivering 36,000 pounds of thrust. The 44-foot-long vehicle is designed for three passengers and one pilot. Test flights could get under way as early as next year, with commercial flights in 2009, says Bob Seto, the company’s vice president. None of these rides will come cheap. Virgin Galactic is asking $200,000 a ticket, and although Blue Origin has yet to set a fare, you can bet it will cost more than Amazon’s two-day shipping upgrade. But even if stratospheric ticket prices don’t seem to be deterring eager space tourists—200 people have already booked flights with Virgin Galactic—most companies are well aware that a deadly crash could hurt the flow of wealthy passengers. So with that in mind, the industry is proceeding in the spirit of Blue Origin’s lofty Latin corporate motto, Gradatim ferociter.Roughly: “Step by step, ferociously.”

Mars Pole Holds Enough Ice to Flood Planet

Mars's southern polar ice cap contains enough water to cover the entire planet approximately 36 feet (11 meters) deep if melted, according to a new radar study. It's the most precise calculation yet for the thickness of the red planet's ice, according to the international team of researchers responsible for the discovery.

Using an ice-penetrating radar to map the south pole's underlying terrain, the scientists calculated that the ice is up to 2.2 miles (3,500 meters) thick in places, said the study's leader, Jeffrey Plaut of NASA's Jet Propulsion Laboratory in Pasadena, California. The radar, from the Mars Express orbiter, also revealed the surprising purity of the ice, Plaut added. On average, the ice cap contained less than 10 percent dust, he said. The study will appear in tomorrow's issue of the journal Science. The polar ice cap may also contain some frozen carbon dioxide, or dry ice, Plaut said. But there can't be much of it, because such a thick layer of dry ice would start to ooze sideways under its own weight. "Only water ice could support itself that way," Plaut said. The research team also found a series of depressions buried beneath the ice only 180 miles (300 kilometers) from the pole. These are probably impact craters, Plaut said, though they might also be features caused by erosion, similar to ones found elsewhere on Mars. "We don't completely understand them, because we have only a vague image of them," Plaut said. But, significantly, the team didn't find a large depression under the ice.

Boeing/NASA Blended-Wing Experiment Ready To Launch

Boeing's X-48B blended-wing-body (BWB) experimental aircraft is just about ready for its first test flight, Business 2.0 reported on Tuesday. The scale model, with a wingspan of 21 feet, should take to the air by the end of this month at Edwards Air Force Base in California. The aircraft has long been under development in a joint program involving NASA, the U.S. Air Force and Boeing's Phantom Works. The blended-wing design creates an aerodynamic shape that doesn't require a conventional tail, reducing drag and dramatically improving fuel efficiency. A military version of the aircraft could be on the market by 2022, with a passenger version flying by 2030.

U.S. Developing Jets That Fly Five Times the Speed of Sound

The U.S. Air Force is preparing to test a new vehicle that could make missiles—and someday, jets—travel ten times faster than those flown today, military officials say. The research vehicle, known as the X-51A, will be able reach hypersonic speeds when it is tested in 2009.

Hypersonic speeds are above Mach 5—faster than five times the speed of sound. "This could significantly change an operation's tempo," said Bob Mercier, deputy for technology in the aerospace propulsion division at the Air Force Research Laboratory in Ohio. A cruise missile today takes about 90 minutes to reach a target located 600 nautical miles (1,100 kilometers) away. A hypersonic cruise missile using the X-51A would reach its target in 10 minutes. "The military obviously has a need for speed," said Paul Reukauf, a hypersonic technology expert at NASA's Dryden Flight Research Center in Edwards, California. Flight engineers define three categories of speed: subsonic, supersonic, and hypersonic. The way air flows around the aircraft distinguishes the categories, Reukauf explained. At subsonic speed, which is below the speed of sound, shock waves are absent. At supersonic speed, shock waves form on the aircraft as it flies through the air. As the air pressure rises through these waves, a sonic boom is generated. At hypersonic speeds, the shock waves form very close to the aircraft, and engineers are developing ways to harness the power of these waves. "The lift and drag and performance of the airplane can essentially be explained … by the resulting forces of the molecules of the air hitting the airplane," Reukauf said.

Saturn's Icy Moon May Have Been Hot Enough for Life

One of the places in the solar system most likely to have extraterrestrial life may have gotten off to a hot, highly radioactive start, scientists reported yesterday at a meeting in Houston, Texas. Enceladus, a moon of Saturn, stunned scientists two years ago when NASA's Cassini orbiter discovered geyser-like jets of water vapor shooting into space from its south pole.

Now a new study of Enceladus's plume finds that it's rich in nitrogen gas. "This is interesting, because nitrogen is hard to produce in a body as small as Enceladus without significant heat," said John Spencer, a planetary scientist with the Southwest Research Institute in Boulder, Colorado. Spencer who was not part of the study. The find suggests that the moon's core once reached temperatures around 1,070 degrees Fahrenheit (577 degrees Celsius)—hot enough to convert Enceladus's internal stores of ammonia into nitrogen. This may also be hot enough to produce the possible precursors for life, said the study's lead author, Dennis Matson of the Jet Propulsion Laboratory (JPL) in Pasadena, California. "We've got an organic brew, a heat source, and liquid water—all key ingredients for life," Matson said in a press statement. "And while no one is claiming that we have found life, by any means, we probably have evidence for a place that might be hospitable to life." Cassini scientist Carolyn Porco of the Space Science Institute in Boulder, Colorado, said Enceladus should be a leading candidate site for future probes in search of extraterrestrial life.