Tuesday, 30 July 2013

Spacecraft sees giant 'hole' in sun

By Megan GannonPublished July 29, 2013
Space.com




The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun’s north pole on July 18, 2013, at 9:06 a.m. EDT. (ESA&NASA/SOHO)


A space telescope aimed at the sun has spotted a gigantic hole in the solar atmosphere — a dark spot that covers nearly a quarter of our closest star, spewing solar material and gas into space.

The so-called coronal hole over the sun's north pole came into view between July 13 and 18 and was observed by the Solar and Heliospheric Observatory, or SOHO. NASA released a video of the sun hole as seen by the SOHO spacecraft, showing the region as a vast dark spot surrounded by solar activity.

Coronal holes are darker, cooler regions of the sun's atmosphere, or corona, containing little solar material. In these gaps, magnetic field lines whip out into the solar wind rather than looping back to the sun's surface. Coronal holes can affect space weather, as they send solar particles streaming off the sun about three times faster than the slower wind unleashed elsewhere from the sun's atmosphere, according to a description from NASA.

"While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere," NASA's Karen Fox at the agency's Goddard Space Flight Center in Greenbelt, Md., explained in an image description.

These holes are not uncommon, but their frequency changes with the solar activity cycle. The sun is currently reaching its 11-year peak in activity, known as the solar maximum. Around the time of this peak, the sun's poles switch their magnetism. The number of coronal holes typically decreases leading up to the switch.

After the reversal, new coronal holes appear near the poles. Then as the sun approaches the solar minimum again, the holes creep closer to the equator, growing in both size and number, according to NASA.

The $1.27-billion SOHO satellite was launched in 1995 and is flying a joint mission between NASA and the European Space Agency (ESA). It watches solar activity from an orbit about the Lagrange Point 1, a gravitationally stable spot between Earth and the sun that is about 932,000 miles from our planet.




Read more: http://www.foxnews.com/science/2013/07/29/spacecraft-sees-giant-hole-in-sun/#ixzz2aXYd3Q86

How Giant Black Holes Spin: New Twist Revealed

by Mike Wall, SPACE.com Senior Writer | July 29, 2013 07:01pm ET



An artist’s impression of a supermassive black hole at the centre surrounded by matter flowing onto the black hole in what is termed an accretion disk. Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole's spin.




A newly discovered way to determine the spin of monster black holes could help shed light on the evolution of these bizarre objects and the galaxies they anchor.

Astronomers watched as a black hole that sits at the core of a spiral galaxy 500 million light-years from Earth gobbled up gas and dust from its surrounding accretion disk. They were able to measure the distance between the inner edge of the disk and the black hole, which, in turn, allowed them to estimate the black hole's spin.

“If a black hole is spinning, it drags space and time with it, and that drags the accretion disk, containing the black hole's food, closer towards it," study lead author Chris Done, of the University of Durham in the United Kingdom, said in a statement. "This makes the black hole spin faster — a bit like an ice skater doing a pirouette." [Gallery: Black Holes of the Universe]


WATCH THE VIDEO HERE


Researchers said the technique could help astronomers address broad questions about galactic evolution, which is intimately tied to the growth and activity of the supermassive black holes that lurk at the heart of most, if not all, galaxies.

"Understanding this connection between stars in a galaxy and the growth of a black hole, and vice versa, is the key to understanding how galaxies form throughout cosmic time," Done said.

Done and her colleagues used the European Space Agency's XMM-Newton satellite to study the distant supermassive black hole, which contains as much mass as 10 million suns.

This black hole blasts out prodigious amounts of energy as it feeds on the material in its accretion disk. XMM-Newton observed this output in optical, ultraviolet and X-ray wavelengths, enabling the astronomers to measure how far the disk sits from the black hole.

Astronomers have calculated the spin of supermassive black holes before. In February, for example, a different research team determined the rotation rate of the black hole at the center of a spiral galaxy called NGC 1365. That group inferred the spin speed by measuring the distortion of high-energy light emitted by iron atoms in the accretion disk.


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It's tough to describe black-hole spin rates because they don't really translate into familiar terms, such as miles per hour. For example, the NGC 1365 team, which used observations by XMM-Newton and NASA's NuStar spacecraft, found the black hole's rotation rate to be 84 percent of the maximum allowed by Einstein's theory of general relativity.

In the new study, Done and her team estimated that the black hole found 500 million light-years away — which is powering a superluminous "active galactic nucleus" known as PG1244+026 — has a relatively low spin rate.

"This contrasts with the recent X-ray determinations of (close to) maximal black hole spin in other [similar galaxies] based on relativistic smearing of the iron profile," the researchers wrote in the study, which was published online today (July 29) in the journal Monthly Notices of the Royal Astronomical Society.

"Better high-energy data are required in order to determine whether this new method gives a spin estimate which is consistent with that derived from the iron line, or whether it instead reveals a lack of understanding of disc continuum emission and/or of disc reflection," the team wrote.


NASA spots eclipsing planet in X-rays for first time

Chandra’s X-rays also detected a faint red companion to the main star in HD 189733.



Photo credit: NASA



Science Recorder | Stephanie Verkoeyen | Tuesday, July 30, 2013



Planets outside our solar system, commonly referred to as exoplanets, were discovered almost 20 years ago. Now, for the first time, X-ray observations have detected an exoplanet passing in front of its parent star.

The advantageous alignment occurred in the HD 189733 system, 63 light-years from Earth. As the planet transited its star, both NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM Newton Observatory observed a dip in X-ray intensity.

Katja Poppenhaeger of Harvard led the study, which is to be published in The Astrophysical Journal next month. According to Poppenhaeger, thousands of planets have been detected in optical light, but being able to study one in X-rays reveals new information about its properties.

The planet, known as HD 189733b, is similar in size to Jupiter, but is in very close orbit around its star, a condition referred to as a “hot Jupiter.” HD 189733b is the closest hot Jupiter to Earth, making it a prime target for astronomers. NASA’s Kepler space telescope has been used to study it at optical wavelengths, while NASA’s Hubble Space Telescope has confirmed it is blue in color.

In this new study, clues have been revealed regarding the size of the planet’s atmosphere. During the transits, the spacecraft observed a decrease in light. X-ray light experienced a decrease three times greater than did optical light, which suggests that there may be extended layers of the planet’s atmosphere transparent to optical light, but opaque to X-rays.

“However, we need more data to confirm this idea,” said co-author Jurgen Schmitt.

Researchers are also learning how the planet and the star can affect one another. For a decade, astronomers have known that ultraviolet and X-ray radiation has been evaporating the atmosphere of HD 189733b over time, losing an estimated 100 million to 600 million kilograms of mass per second.

The planet’s extended atmosphere has made it a larger target for high-energy radiation, with its atmosphere thinning about 25 percent to 65 percent faster than if the atmosphere were smaller.

Chandra’s X-rays also detected a faint red companion to the main star in HD 189733. Though likely formed at the same time, the main star appears to be at least 3 billion years younger than its companion due to a higher rotation. The main star also has displayed higher levels of magnetic activity, and is about 30 times brighter in X-rays than its companion.

This unusual activity may result from having a big planet as a companion, according to Poppenhaeger. The hot Jupiter may be keeping the star’s rotation and magnetic activity high as a result of tidal forces, making it behave like a much younger star.

Earlier this month, it was announced that HD 189733b is a true blue planet.

“We saw the light becoming less bright in the blue but not in the green or red. Light was missing in the blue but not in the red when it was hidden,” said Frederic Pont of the University of Exeter. “This means that the object that disappeared was blue.”

Not only is HD 189733b a blue planet, it may rain glass on this alien world.



Read more: http://www.sciencerecorder.com/news/nasa-spots-eclipsing-planet-in-x-rays-for-first-time/#ixzz2aXWpAfDm

Testing the Future: Astronaut in Space Remote-Controls Robot in California

BY ADAM MANN
07.30.13
6:30 AM




NASA's K-10 rover maneuvers around the Roverscape, a pebbly field at the Ames Research Center full of obstacles such as boulders, fake rocks, and steep slopes.



MOUNTAIN VIEW, California – On a pebbled field built next to a parking lot, a small rover scoots forward and expels a long sheet of polyimide plastic from its backside, the third film the probe has deployed. The sheets are arranged in a Y-shaped formation that simulates a radio antenna on the moon.

No one is around to direct the seemingly autonomous robot. But the entire operation is being remote-controlled by Italian astronaut Luca Parmitano, who is flying 400 kilometers overhead in the International Space Station.

This is the second in a series of tests at NASA’s Ames Research Center aimed at taking the next giant leap in humans and robots working together. A technology known as telerobotics may one day allow astronauts to stay in orbit while guiding robots in real time on the surface of another planet. It will let humans explore new places, including perhaps unreachable locations such as the boiling valleys of Venus or the icy oceans of Europa, while lowering the risk to their lives. With a human mind in the loop, the robots will be able to make much quicker decisions and overcome obstacles to range farther than ever before.

“This is a glimpse of the future of space exploration,” said astronomer Jack Burns of the University of Colorado, during the test on July 26.

During the test at Ames, NASA’s K-10 rover is outfitted with an array of sensors. The 1.4-meter-tall robot has several cameras and an overhead LIDAR scanner to build a 3-D map of its environment, and a sophisticated suite of software to help it get around. Parmitano isn’t driving the probe with a joystick up there. He punches instructions on a laptop, telling the robot to go from point A to point B, and K-10 figures out the best path to avoid obstacles and lay down the radio antenna.

In Burns’ vision, within 10 years, astronauts in orbit around the moon could be deploying a much larger version of this radio telescope on the lunar far side. With such an instrument, astronomers could glimpse some of the earliest periods in our universe’s history, when the first stars and galaxies formed. Currently, both ground- and space-based telescopes experience too much radio noise from human technology and the Earth’s ionosphere to get a clear picture of this era. Because the moon acts as a giant shield, the lunar far side is the only place in the inner solar system quiet enough to see this cosmic dawn. Telerobotics would allow NASA to build a radio telescope on the moon for cheaper than it might otherwise.

NASA is currently building a new generation of enormous rockets, the Space Launch System, which could eventually dwarf the Saturn V that launched Apollo astronauts to the moon. By 2021, it may be ready to carry its first crew beyond low-Earth orbit. Burns wants that first mission to go to the far side of the moon, a place humans have hardly explored, set up a 50 to 100 meter radio antenna, and conduct important geological investigations of the moon’s South Pole Aiken Basin, one of the largest impact craters in the solar system.

In trying to convince NASA to seamlessly bring together human and robotic exploration, Burns has a partner in crime: engineer Terry Fong, leader of the agency’s telerobotics group and a self-professed robot geek at heart.

In an ideal telerobotics situation, human operators control a probe on another planet in real time. For the Curiosity rover, currently on Mars, NASA engineers have to send a complex set of instructions to the robot each morning and wait patiently while it executes them. Because it takes light between seven and 20 minutes to travel between Earth and Mars, any problems or change in commands take a very long time to work out and the rover does everything at an extremely slow pace. Furthermore, a large team of engineers is required at mission control to monitor and instruct the robot.

“With this test, it’s the complete opposite,” said Fong. “We have a single operator” who can make changes on the fly and react to unexpected situations with the creativity and problem-solving skills of the human mind.

From his perch on the space station, Parmitano controlled the robot with a Lenovo Thinkpad laptop showing an up-to-the-minute 3-D model of the area around the K-10. Contradicting the idea that everything in space exploration is always state-of-the-art, Fong mentioned the laptop was running Windows XP. But like a good app developer, Fong and his team want to ensure their control system is user friendly. Parmitano only saw the interface he was using to drive the K-10 two hours before the test began, yet he was able to move the robot deftly and accomplish all the required goals fairly quickly.

Fong hopes to develop telerobotics protocols for more than just space exploration. As some Silicon Valley bosses are finding out, it’s easier to send a robot surrogate into the office for you when you’re far away. The remote-controlled robot can navigate the halls and interact with employees.

“It’s the same sorts of obstacles that you have to get around in an office or on another planet,” Fong said.

There are many more situations on Earth where you could send a robot to more safely do what is now a man’s job. One day, advanced human-controlled probes could go exploring deep underground or at the bottom of the ocean, assess and fix damage after a Fukushima-type disaster, operate search-and-rescue when a building collapses, or perform emergency surgery on a battlefield.


Sunday, 28 July 2013

Scientists discover what’s killing the bees and it’s worse than you thought


By Todd Woody @greenwombat July 24, 2013

Outlawing a type of insecticides is not a panacea. AP Photo/Ben Margot



As we’ve written before, the mysterious mass die-off of honey bees that pollinate $30 billion worth of crops in the US has so decimated America’s apis melliferapopulation that one bad winter could leave fields fallow. Now, a new study has pinpointed some of the probable causes of bee deaths and the rather scary results show that averting beemageddon will be much more difficult than previously thought.

Scientists had struggled to find the trigger for so-called Colony Collapse Disorder (CCD) that has wiped out an estimated 10 million beehives, worth $2 billion, over the past six years. Suspects have included pesticides, disease-bearing parasites and poor nutrition. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists at the University of Maryland and the US Department of Agriculture have identified a witch’s brew of pesticides and fungicides contaminating pollen that bees collect to feed their hives. The findings break new ground on why large numbers of bees are dying though they do not identify the specific cause of CCD, where an entire beehive dies at once.

When researchers collected pollen from hives on the east coast pollinating cranberry, watermelon and other crops and fed it to healthy bees, those bees showed a significant decline in their ability to resist infection by a parasite calledNosema ceranae. The parasite has been implicated in Colony Collapse Disorder though scientists took pains to point out that their findings do not directly link the pesticides to CCD. The pollen was contaminated on average with nine different pesticides and fungicides though scientists discovered 21 agricultural chemicals in one sample. Scientists identified eight ag chemicals associated with increased risk of infection by the parasite.

Most disturbing, bees that ate pollen contaminated with fungicides were three times as likely to be infected by the parasite. Widely used, fungicides had been thought to be harmless for bees as they’re designed to kill fungus, not insects, on crops like apples.

“There’s growing evidence that fungicides may be affecting the bees on their own and I think what it highlights is a need to reassess how we label these agricultural chemicals,” Dennis vanEngelsdorp, the study’s lead author, told Quartz.

Labels on pesticides warn farmers not to spray when pollinating bees are in the vicinity but such precautions have not applied to fungicides.

Bee populations are so low in the US that it now takes 60% of the country’s surviving colonies just to pollinate one California crop, almonds. And that’s not just a west coast problem—California supplies 80% of the world’s almonds, a market worth $4 billion.

In recent years, a class of chemicals called neonicotinoids has been linked to bee deaths and in April regulators banned the use of the pesticide for two years in Europe where bee populations have also plummeted. But vanEngelsdorp, an assistant research scientist at the University of Maryland, says the new study shows that the interaction of multiple pesticides is affecting bee health.

“The pesticide issue in itself is much more complex than we have led to be believe,” he says. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”

The study found another complication in efforts to save the bees: US honey bees, which are descendants of European bees, do not bring home pollen from native North American crops but collect bee chow from nearby weeds and wildflowers. That pollen, however, was also contaminated with pesticides even though those plants were not the target of spraying.

“It’s not clear whether the pesticides are drifting over to those plants but we need take a new look at agricultural spraying practices,” says vanEngelsdorp.



Friday, 26 July 2013

NASA: Space centaurs are likely comets

A mystery is solved. Or is it?


Photo credit:

Science Recorder | Drew Adams | Friday, July 26, 2013



Centaurs, small solar system bodies that orbit the sun between Jupiter and Neptune, have long been considered one of the more mysterious cosmic bodies in observable space. Astronomers questioned whether or not the bright objects are asteroids or comets, but a new study released online with the Astrophysical Journal supposes that it finally has the answer.

The name “centaur” was given to the objects due to the duality of their comet/asteroid characteristics, not unlike the dual horse/man dichotomy of the mythical beast. That’s where the similarities stop, however, and even the basic duality of cosmic centaurs may no longer hold applicable now that data from NASA’s Wide-field Infrared Survey Explorer, or WISE, has gathered strong evidence that they are in fact comets.

“Just like the mythical creatures, the centaur objects seem to have a double life,” said James Bauer in a statement from NASA’s Jet Propulsion Laboratory. “Our data point to a cometary origin for most of the objects, suggesting they are coming from deeper out in the solar system.”

Bauer is the lead author of the new study on centaurs, which appeared online on July 22. The phrase “cometary origin” addresses the fact that centaurs might have been active comets in the past or could be active again in the future. These qualities are partly how comets are differentiated from asteroids, which originate from the inner solar system.

The new data from WISE highlights further differences between comets and asteroids and favors centaurs as examples of the former. NEOWISE, the segment of the WISE program dedicated to locating asteroids, performed the largest infrared survey of centaurs and a number of scattered disk objects. It located 52 objects in all, 15 of which are new discoveries.

A study of the bodies’ albedos, or the ratio of light reflected by a cosmic object to that received by it, compared new information of the centaurs’ color to what has been collected in the past. Visible-light data has pegged centaurs as either blue/gray in color or having a red hue. While blue/gray objects can be either comets or asteroids, dark blue/gray objects are typically comets. Reddish objects are usually considered to be asteroids.

Tommy Grav, researcher with the Planetary Science Institute in Tucson, AZ, and co-author of the study, said that comets have surfaces like charcoal and that asteroids are shiny, much like the moon. Two-thirds of the centaurs observed had coloration that was indicative of a comet. It remains unclear if the final third is made up of comets or asteroids.

“That means the small body populations found beyond the Main Asteroid Belt, like the Hildas, Jupiter Trojans and Centaurs, were either formed where they currently are, or they were inbound objects coming from the far reaches of the Solar System that settled into their current orbits,” said Grav in a press release.

For now, NEOWISE will continue to study the centaurs for more information.



Read more: http://www.sciencerecorder.com/news/nasa-space-centaurs-are-likely-comets/#ixzz2a9mMGQrQ

Thursday, 25 July 2013

How Earth Accelerates Electrons to 99.9 Percent of Light Speed

Earth's Van Allen belts (not to be confused with the astrophysical hard-rock 'Van Halen' phenomenon) rocket electrons around the Earth at near light speed. One scientist just figured out how it's done.

By William Herkewitz



Energy from the dynamic sun drives a complex chain of processes in the Earth's magnetosphere that ultimately lead to strong intensifications of the radiation belts.
Geoff Reeves, Los Alamos National Laboratory

July 25, 2013 2:00

As the Sun's churning surface lets loose a belch of white-hot flame, it sends out a storm of radiation that washes over the solar system. Luckily for us, Earth's magnetic field shields us from most of these deadly rays. But overhead, something strange and lethal is happening when the solar wind bombards the Earth. A band of radioactive particles circling the planet, called the outer Van Allen belt, starts to charge up like a rail gun. It whips electrons along on its circular racetrack at a breakneck pace—near light speed. The powerful band ebbs and flows with solar radiation, but until today, nobody could be sure how it was creating such swift and energetic particles.

"This is like watching a natural particle accelerator in space," says Geoffrey Reeves, a magnetic field researcher at Los Alamos National Laboratory.

Reeves and a team of scientists published research today in the journal Science describing the bizarre way the outer Van Allen belt—which orbits around the Earth like a giant doughnut—accelerates electrons to more than 99.9 percent of the speed of light. Discounting light itself, Reeves says, "these electrons are the fastest things the Earth creates naturally." And they aren't simply a high-velocity curiosity: They pose a threat to the International Space Station and to commercial satellites. The particles can burst through the protective shielding—causing temporary computer failures—and cause degradation to vital onboard equipment such as solar panels.


Surfing Radio Waves
Reeves and his team, with the help of a pair of newly launched NASA satellites called the Van Allen Probes, showed that the electrons in the belt gain their breathtaking velocity by hitching rides on radio waves. Daniel Baker, an astrophysicist with the study from the University of Colorado at Boulder, says that as solar radiation crushes against the Earth's magnetic field, a surge of radio and other waves begin to pump through the Van Allen belts. By chance, some of the radio waves are the exact frequency as electrons already twirling through the belt at slow speeds. "So the electrons hitch a ride—sort of surfing on these waves—and can be carried to these high speeds," Baker says. "It's a subtle but very powerful interaction."



Reeves says the new NASA satellites, launched last August, are the main reason researchers ID'd this radio wave surfing. "We had the right instruments, the satellites were in the right orbit, and we had two of them," he says. Previous satellites used to measure the Van Allen belts lacked the tools or orbit to take successive measurements deep within the hazardous core of the belts. They could get a snapshot, but not a moving picture, of how the Van Allen belts evolve and respond to solar wind. The heavily shielded Van Allen probes repeatedly darted through the heart of the Van Allen belt, quickly measuring the entire range of slow to speedy electrons.

Knowing how Earth's natural electron accelerator works is important for more reasons than just satisfying scientific curiosity. Because of the Van Allen belts' doughnut-like shape and constant expansion and contraction with solar wind, their high-energy electrons can impact almost every satellite in orbit. "It's a rare satellite that isn't affected by this," Baker says, "and we have numerous examples through the last couple of decades where we've seen absolutely confirmed evidence that this is a serious operational problem."

Still, Jean-Luc Froeliger, the vice president of satellite engineering at Intelsat, which operates the world's largest commercial satellite fleet, cautions that while the Van Allen belts' high energy particles can do long-term damage to satellites, all modern satellites are built to withstand this particle barrage with extra shielding covering vital components, and major damage is rare. "I don't know any commercial satellite that has been totally destroyed by high energy elections," Froeliger says, "but there is certainly an impact, in that the solar arrays degrade the more a satellite's bombarded by particles."


Forecasting Space Storms
The researchers hope that by understanding the Van Allen belt, they can predict when it will be at its worst, and develop methods to keep our satellites better protected. Figuring out how the electrons accelerate is the first step. "If we want to be able to predict when the radiation belts are going to get very intense, we have to know what's the source of the energy," Reeves says.

The Van Allen belts are still by no means fully understood. Vassilis Angelopoulos, a magnetic field expert at the University of California, Los Angeles, who was not involved in the study, points out that while we've discovered how the electrons are accelerated, we still don't know how solar radiation creates these surfable radio waves. "What generates the waves to begin with still remains to be solved," Angelopoulos says. "While we're putting to rest one of the important questions about the Earth's [radioactive belts], there is still a lot of work to be done to reach a predictive capability within our models."

Reeves argues that in a world increasingly reliant on all the technologies satellites foster—from GPS to telecommunications—working to protect satellites is an essential goal. "Even when you swipe your credit card at the gas station," he says, "that transaction will go through a satellite before it goes to your bank."



Read more: How Earth Accelerates Electrons to 99.9 Percent of Light Speed - Popular Mechanics

UK team designs human mission to Mars

24 July 2013 Last updated at 06:54 GMT

By Neil Bowdler
Science and health reporter, BBC News


A team of scientists from Imperial College London discuss how we could put a human on Mars


Scientists at Imperial College London have designed a concept mission to land astronauts on Mars.

The plan envisages a three-person crew journeying to Mars aboard a small two-part craft.

The craft would rotate to generate artificial gravity and use a heat shield to protect itself against solar flares.

The crew would then return to Martian orbit in a pre-sent craft fuelled using ice from beneath the planet's surface.

The concept, developed in conjunction with the BBC, is intended to spark further debate about the technical obstacles and risks that would have to be overcome in order to put humans on Mars.


How to put a human on Mars

Click to visit interactive site

"Every part of this mission scenario has been demonstrated one way or the other, including the in situ propellant production on the surface of Mars," said Prof Tom Pike, who led the Imperial design team.

"There are big, big jumps between a demonstration at one level and putting together the engineering systems for a mission, but they are engineering challenges. They are not fundamentally about making new discoveries."

The new Imperial concept comes amid renewed interest in the Red Planet with two private groups having proposed missions in recent months.

The Imperial team have designed a two-part craft, consisting of a Martian lander with a heat shield, inside which the crew would also ascend into Earth orbit.

Directly beneath the lander on the launch pad would be a "cruise habitat vehicle", a cylindrical craft split into three floors and measuring some 10m (30ft) in height and 4m in diameter.

Once in Earth orbit, the astronauts would move from the lander into the larger habitat vehicle before a rocket burst would propel the conjoined craft on a trajectory to Mars. The quickest journey time would be nine months when Earth and Mars are in optimum alignment.


Shortly into the journey, the lander and cruise vehicle would unwind from each other on a steel cable tether to a distance of some 60m. Short thruster bursts from both vehicles would then set them spinning around a centre of gravity.

This would create artificial gravity within the habitat vehicle similar to Earth's gravity, which the scientists believe would prevent the type of muscle and bone wastage that weightlessness would cause, which would render the astronauts unable to walk on Mars once they arrived.

Later in the mission, the spin rate could be reduced to better emulate Martian conditions, where gravity is 40% that on Earth.

"We've obviously got some real issues with a long-term mission in terms of the de-conditioning which goes on in the space environment," Ryan Robinson, the Imperial team's physiologist, told BBC News.

"Bones loss [in a weightless environment] is about 1-2% a month and if they're landing they'll be susceptible to fractures if they've got to be exerting themselves."

During the journey, the crew's health would be monitored closely with wireless sensors - but they would rely entirely on medication aboard the craft and the skills of their fellow crew members should they fall sick.



A crew would face cosmic and solar radiation en route and on Mars

The long journey and confined quarters could also affect their mental health, and conflicts between the crew could arise.

During the journey, the craft could deploy a number of measures to try to reduce the threat to the astronauts from solar and cosmic radiation, the former from the Sun, the later emanating from beyond our solar system.

Water could run within the shell of the cruise craft to absorb radiation, while the Imperial team also examined the idea of fitting superconducting magnets to the craft, which would generate a magnetosphere to deflect solar and cosmic radiation in the way the Earth's natural magnetosphere does.

The crew would also deploy emergency procedures should satellites detect a major incoming solar flare.

This would involve winding in the tether and re-directing the lander's heat shield towards the Sun to protect the astronauts in the cruise craft.

The crew would also put whatever they could find between them and the front of the vehicle to absorb the solar burst.



Artificial gravity is proposed for the craft to prevent muscle and bone loss on the journey to Mars

Even with such measures, a solar flare could still kill, or result in cancers. Cosmic radiation could also take its toll.

"We've got some great results from the Mars curiosity rover," said Imperial's Martin Archer, who specialises in solar and cosmic radiation.

"On its trip to Mars, it measured the radiation from these galactic cosmic rays and it was exposed to quite a lot - about two-thirds of the level that Nasa is prepared to risk over the whole of an astronaut's life, just on the way there and back again."

Once the craft reaches Martian orbit, it would contract together and the astronauts would pass into the lander ready for detachment and descent.

Its shield would absorb the heat of entry before being jettisoned and then multiple parachutes would deploy to slow the craft, with thrusters used to further slow and guide it through the final metres to the landing site.

The Imperial team propose a landing site near the equator, where milder conditions exist.

They would hope to land near a pre-sent Martian habitat module and rover, although the rover could be robotically controlled to travel from the habitat to the landing site if the distance was too great for a crossing on foot.

Then the Martian visit would begin - a first human landing on another planet.


The time spent on the Martian surface would be dictated by the next time Earth and Mars aligned for a speedy return home. It could be two months, or we might choose to spend more than two years on Mars, says the Imperial team.

It is during this time that the human crew could try to demonstrate why humans could still outperform robots in analysing and understanding the Martian environment.

"Some people think that the use of humans is just something that is popular and attractive from an adventure and inspirational point of view, but there are also real scientific benefits for sending humans," said Prof Mark Sephton, the team's geologist.

"Humans can data process while they're walking around, while they're looking at rocks. They're probably the most sophisticated computer, the most sophisticated robotic living organism that we can imagine."

Radiation would remain a danger during the stay, with Mars possessing no magnetosphere to shield the surface from cosmic and solar rays. Shovelling up soil from the surface during the mission and part-burying the habitat module could help, as could staying inside during a solar burst.

Then comes the return home, which would be far from simple.

The approach taken by the Imperial scientists would be to pre-send both the habitat module, rover and a return vehicle before any human launch.

The return vehicle would land at a latitude where water ice would be found in large amounts just a few centimetres beneath the surface. Robotic devices would mine the ice, which would then be split into hydrogen and oxygen using electrolysis.

These gases could be used as fuels on their own, or the hydrogen could be combined with carbon dioxide from the Martian atmosphere using a catalyst to produce methane, which is a more stable and energy-dense fuel than hydrogen.



The team suggest we could mine Mars for ice to fuel the return craft

As the Imperial team propose landing near the equator, a crew would have to travel by rover to a cooler latitude where the return vehicle and ice-mining devices would be waiting. Several hundreds of kilometres may have to be crossed, posing both risks and opportunities to further explore the Martian landscape.

Should they make it safely, the crew would have a narrow launch window to ensure the quickest most fuel-efficient return to Earth.

After leaving Mars, the return vehicle would dock with the orbiting cruise vehicle and replace the Martian lander as the counter-balance within the spinning tethered structure en route to Earth. Like the lander, the return vehicle would have to be fitted with a shield to protect the crew during extreme solar activity.

After at least nine months, the craft would reach Earth orbit and dock with the International Space Station before the astronauts could take a Soyuz capsule home, the team envisages.

The new Imperial concept comes amid renewed interest in the Red Planet, with two private groups having proposed missions.

Businessman and former space tourist Dennis Tito wants to send an American couple on a mission beginning in 2018 that would pass within 100 miles (160km) of Mars before using the planet's gravity to "slingshot" the craft back to Earth.

The Dutch project Mars One proposes putting a human colony on the planet beginning in 2023, while SpaceX chief executive Elon Musk has spoken of sending a private human mission to Mars within 12-15 years.

The US, Russian, European and Chinese space agencies maintain long-term plans to put humans on Mars.


Wednesday, 24 July 2013

Scientists find strange, shape-shifting particles

By Clara MoskowitzPublished July 23, 2013
LiveScience




A candidate electron neutrino appears in the Super Kamiokande particle detector in Japan like this. In July 2013 researchers announced they'd definitively measured muon neutrinos oscillating flavor into electron neutrinos. (T2K)


Exotic particles called neutrinos have been caught in the act of shape-shifting, switching from one flavor to another, in a discovery that could help solve the mystery of antimatter.

Neutrinos come in three flavors: electron, muon and tau and have been known to change, or oscillate, between certain flavors. Now, for the first time, scientists can definitively say they've discovered muon neutrinos changing into electron neutrinos.

The discovery was made at the T2K neutrino experiment in Japan, where scientists sent a beam of muon neutrinos from the J-PARC laboratory in Tokai Village on the eastern coast of Japan, streaming 183 miles away to the Super-Kamiokande neutrino detector in the mountains of Japan's northwest.

The researchers detected an average of 22.5 electron neutrinos in the beam that reached the Super-Kamiokande detector, suggesting a certain portion of the the muon neutrinos had oscillated into electron neutrinos; if no oscillation had occurred, the researchers should have detected just 6.4 electron neutrinos.[Wacky Physics: The Coolest Little Particles In Nature]



'[It] may lead us to understand why there is so much more matter than antimatter in the universe. The neutrino may be the very reason we are here.'
- physicist Alfons Weber of the U.K.'s Science and Technology Facilities Council



In 2011, T2K scientists announced they'd seen indications that this shape-shifting was taking place, but they couldn't say with certainty that the effect wasn't one of chance. The experiment has now collected enough data for the researchers to say the probability of this effect being produced by random statistical fluctuations is less than one in a trillion.The results were announced Friday (July 19) at the European Physical Society meeting in Stockholm.

The discovery opens an intriguing avenue for studying antimatter, the strange cousin of matter that's mysteriously missing in the universe. Scientists think the Big Bang produced about as much matter as antimatter, but most of this antimatter was destroyed in collisions with matter, leaving a slight excess of matter to make up the universe we see today.

The best shot at explaining why matter won out in this cosmic struggle is to find instances where a matter particle behaves differently than its antimatter counterpart. Many physicists suspect that neutrino oscillations might be just the type of occasion to see this difference.

Now that the researchers have observed this oscillation pattern in neutrinos, they can recreate the experiment with a beam of anti-muon neutrinos, and find out whether they change more or less often into anti-electron neutrinos.

"Our findings now open the possibility to study this process for neutrinos and their antimatter partners, the anti-neutrinos," physicist Alfons Weber of the U.K.'s Science and Technology Facilities Council and the University of Oxford, said in a statement. "A difference in the rate of electron or anti-electron neutrino being produced may lead us to understand why there is so much more matter than antimatter in the universe. The neutrino may be the very reason we are here."

This next phase of the project will likely take at least a decade, the researchers said.

"We have seen a new way for neutrinos to change, and now we have to find out if neutrinos and anti-neutrinos do it the same way," T2K team member Dave Wark of the Science and Technology Facilities Council said in a statement. "If they don't, it may be a clue to help solve the mystery of where the matter in the universe came from in the first place. Surely answering that is worth a couple of decades of work!"


Read more: http://www.foxnews.com/science/2013/07/23/strange-particles-shape-shift-from-one-flavor-to-another/#ixzz2Zxx80qKG

Dolphins 'call each other by name'By Rebecca MorelleScience reporter, BBC World Service


The research sheds new light on the intelligence of dolphins


Scientists have found further evidence that dolphins call each other by "name".

Research has revealed that the marine mammals use a unique whistle to identify each other.

A team from the University of St Andrews in Scotland found that when the animals hear their own call played back to them, they respond.

The study is published in the Proceedings of the National Academy of Sciences.

Dr Vincent Janik, from the university's Sea Mammal Research Unit, said: "(Dolphins) live in this three-dimensional environment, offshore without any kind of landmarks and they need to stay together as a group.

"These animals live in an environment where they need a very efficient system to stay in touch."

Signature whistles

It had been-long suspected that dolphins use distinctive whistles in much the same way that humans use names.

Previous research found that these calls were used frequently, and dolphins in the same groups were able to learn and copy the unusual sounds.

But this is the first time that the animals response to being addressed by their "name" has been studied.

Most of the time they can't see each other, they can't use smell underwater... and they also don't tend to hang out in one spot”
Dr Vincent Janik
University of St Andrews


To investigate, researchers recorded a group of wild bottlenose dolphins, capturing each animal's signature sound.

They then played these calls back using underwater speakers.

"We played signature whistles of animals in the group, we also played other whistles in their repertoire and then signature whistles of different populations - animals they had never seen in their lives," explained Dr Janik.

The researchers found that individuals only responded to their own calls, by sounding their whistle back.

The team believes the dolphins are acting like humans: when they hear their name, they answer.

Dr Janik said this skill probably came about to help the animals to stick together in a group in their vast underwater habitat.

He said: "Most of the time they can't see each other, they can't use smell underwater, which is a very important sense in mammals for recognition, and they also don't tend to hang out in one spot, so they don't have nests or burrows that they return to."

The researchers believe this is the first time this has been seen in an animal, although other studies have suggested some species of parrot may use sounds to label others in their group.

Dr Janik said that understanding how this skill evolved in parallel in very different groups of animals could tell us more about how communication developed in humans.



Sunday, 21 July 2013

Powerful Atlas 5 lifts massive Navy satellite into orbit

BY JUSTIN RAY
SPACEFLIGHT NOW
Posted: July 19, 2013


Leaping off the launch pad Friday in its most powerful arrangement to boost its heaviest payload into orbit, a United Launch Alliance Atlas 5 rocket successfully deployed the second in a series of sophisticated spacecraft to grow the U.S. Navy's new mobile communications network that will span the globe.



Credit: Walter Scriptunas / Spaceflight Now
See more launch photos


The energetic rocket, created by attaching five strap-on solid-fuel motors to the kerosene-fed main stage to deliver two-and-a-half million pounds of thrust, launched from Cape Canaveral at 9:00 a.m. EDT.



The 206-foot-tall rocket blasted off after its overnight countdown progressed smoothly and a brief hold for upper level wind conditions to clear.

It begins a string of five national security launches that the Air Force will perform with United Launch Alliance in a three-month span through October, using both Atlas and Delta 4 rockets from the Cape and Vandenberg Air Force in California. The future flights will deploy two Air Force communications spacecraft, a massive spy satellite for the National Reconnaissance Office and a new GPS bird.

The surge began in successful fashion with the Navy's Mobile User Objective System satellite No. 2, taking the next step to construct a worldwide communications system using 3G-cellular technology for ships, submarines, aircraft, land vehicles and terminals in the hands of troops.

"When the constellation is fully populated, users will be able to speak to any other user on the globe," said Navy Capt. Paul Ghyzel, manager of the Satellite Communications Program Office.



Credit: Walter Scriptunas / Spaceflight NowSee more launch photos


"Today, the traditional (satellite communications) system, two users who want to communicate with each other need to be underneath the same satellite. MUOS changes that.



"So with the second satellite being launched and checked out and put into operations, we'll continue our coverage (expansion) of the globe and basically double it because we will have two satellites on-orbit working towards our ultimate objective of true global coverage once we get the remaining satellites on-orbit. That's really the big coverage gain (with Friday's launch).

"From a technical standpoint, with two satellites on-orbit it allows us to verify and validate how the system works. As we test out the system, we'll be communicating with a user that's underneath satellite No. 1, the traffic, both voice and data traffic will be routed through the ground network and routed up through the second satellite in several of our test scenarios to be sent to a user or multiple users that are underneath the footprint of the second satellite."

MUOS 1 was launched in February 2012 and put into operation by year's end. MUOS 2 will complete its post-launch orbit shaping in about 8 days, then deploy its solar arrays and twin umbrella-like antenna reflectors to achieve the "flight configuration" about 12 days after launch.

Then begins several months of satellite system and payload testing before builder Lockheed Martin hands over the craft to the government for additional checks in advance of setting it operational in early 2014.

From its eventual spot in geosynchronous orbit, a parking spot 22,300 miles up, the expansive footprint of MUOS 2 will cover nearly a third of the planet. However, what geographical area of the globe the craft will cover hasn't been finalized yet, officials said.

MUOS serves a dual-provider of both voice traffic currently routed by the Navy's existing generation, albeit aging, Ultra High Frequency Follow-On spacecraft, but it also creates a new era of mobile communications built around 3G cellular technology to relay narrowband tactical information such as calls, data messaging, file transfers and email on rates of up to 384 Kilobits per second.



An artist's concept of MUOS. Credit: Lockheed Martin


"One of the way we frequently describe the new capabilities that MUOS brings is think of a cellphone," Ghyzel said.



"The architecture that we've built with the satellite constellation and with the global ground network, the satellite is the celltower. Anybody that is using a radio that is capable of communicating with MUOS, when they speak their transmission is picked up by the satellite and then routed like a cellular system would route to wherever it needs to be to talk to the guy on the other end.

"So if you are driving down the interstate and you walk to talk to a guy one county over, you may be using the same tower. For Bob to talk to Jim.

"But if Bob is in Florida and wants to talk to his wife in Seattle, he can pick up a cellphone, the tower next to the interstate he is driving on is going to pick up that call, but then it is going to go through a fiber optic network to get to a celltower that is closest to his wife in Seattle and that tower is going to send that call to her cellphone.

"Much like for us in MUOS, if you got somebody that's in Hawaii that needs to talk to a ship that's 200 miles off Hawaii, that traffic is going to go through the satellite that is over the Pacific.

"But if that ship commander needs to talk to somebody that is in Afghanistan, then they are going to transmit over MUOS, the satellite over the Pacific is going to up that transmission, but (it is) then routed through the rest of the MUOS network to the satellite that's going to be over the Indian Ocean, eventually, and then down into Afghanistan.

"You can think of the satellites as the celltowers in the sky. That's a really good way to think of how the system works."

MUOS 3 is expected to launch in about 12 months, followed by MUOS 4 in the summer of 2015. The constellation will feature four primary satellites and one on-orbit spare, all designed and built as clones of each other.



Origin of gold found in rare neutron-star collisions

Posted: Sunday, July 21, 2013 8:00 am

By Joel Achenbach The Washington Post



Gold, the most widely beloved of the precious metals, might have its origin in extremely rare and violent explosions in the far reaches of outer space. The bling apparently begins with a blam.

For many years, scientists had theorized that the heavy elements of the periodic table, such as gold, platinum, lead and uranium, had their origin in supernova explosions. But the source, scientists have announced, might be even more exotic: the collision of two ultra-dense objects called neutron stars.

The elements on Earth are all of cosmic origin. Carbon and oxygen atoms in our bodies, for example, come from the interior of stars, where they were formed under high pressure and heat. They were later spewed into the universe in supernova explosions. But what hasn’t been known is whether these supernova events could account for the heaviest of the elements. A heavy element such as gold has 79 protons, 79 electrons and 118 neutrons. That’s a lot of mass for one atom. Most of the elements are simpler; gold and the other heavy elements are cosmically extravagant.

The neutron stars might provide the explanation.

Neutron stars are the collapsed cores of stars that have exploded in a supernova. A neutron star might be roughly the diameter of Washington but contain as much mass as our sun, all of it crammed together by the force of gravity, until even the atoms have collapsed, leaving the object with the density of an atomic nucleus.

Most of these cosmic fruitcakes are solitary wanderers, but some are paired up, as remnants of binary stars. They will orbit a common point in space and gradually drift closer and closer. One day, they will collide.

Astronomers are fortunate in that the universe is so vast, containing many billions of galaxies, that any all-sky survey might possibly see something even as rare as a neutron-star collision. So it was that on June 3, NASA’s Swift space telescope observed a flash of light, called a short gamma-ray burst (GRB), in an extremely distant galaxy in the constellation Leo.

Astronomers scrambled to reobserve that tiny patch of space with a powerful telescope in Chile and with the Hubble Space Telescope.

They saw something glowing where they’d earlier seen the GRB. After comparing their observations with theoretical models, the astronomers concluded that they were seeing the radioactive afterglow from a huge quantity of heavy metals formed by a neutron-star smashup.

This observation potentially explains this type of short-duration GRB. These flashes of light can briefly outshine an entire galaxy.

“When they make contact, several exciting things happen very quickly,” said Edo Berger, an astronomer who led the research at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Berger said. “Most of the material actually collapses to form a black hole. Some of the material then gets sucked into the black hole. That is the event that causes the gamma-ray burst. Some of the material gets spewed out into space. That material, since it came from neutron stars, is very rich in neutrons, and is very efficient at forming these heavy elements, including gold.”

Berger said the neutron-star collisions produce essentially everything up and down the periodic table.

The gold is basically dust in the wind, atomized, until it winds up in a cloud of material that can coalesce, through the force of gravity, into a solar system of planets with a star at the center.

Then the gold atoms have to find one another and become concentrated.



Saturday, 20 July 2013

Is sending humans to Mars actually feasible?

"The challenge ahead is epic, but historic," says Buzz Aldrin. "We are on a pathway to homestead the Red Planet."
By The Week Staff | 10:00am EST


The next hot location for homesteaders                                      NASA/Pat Rawlings/SAIC

Why go to Mars?

The idea of a manned journey to Mars has animated science fiction for more than a century, and since the dawn of the space age, plans have been proposed for how it might be done. But for decades, any real momentum toward that dream seemed lost. In 1989, a plan advanced by President George H.W. Bush to send a manned mission to the Red Planet was shelved when its costs were estimated at more than $500 billion. In recent years, however, the prospects of a Martian voyage have been looking up. In 2010, the Obama administration called on NASA to set "far-reaching exploration milestones," including sending astronauts to Mars by the mid-2030s. But NASA still has no budget for a manned mission, let alone the technology to land humans there safely and then bring them back. Several commercial spaceflight companies are working on plans to send people to Mars in about a decade. Former astronaut Buzz Aldrin believes it's possible. "The challenge ahead is epic, but historic," he says. "We are on a pathway to homestead the Red Planet."

What would such a mission take?

Just getting humans to Mars would require new solutions to some stiff challenges. At the closest points of their orbits, Earth and Mars are 34 million miles apart, and astro-engineers figure it would take a manned spacecraft five to 10 months to reach Mars. That is a long time for astronauts to be in interplanetary space, where they'd need much tougher protection against cancer-inducing space radiation than they do in Earth's orbit. A trip to Mars would require vast quantities of equipment, food, and fuel. Some have suggested sending supplies separately to allow astronauts to travel in a lighter — and faster — vessel. But even if a manned mission reached Mars' orbit in good order, landing there safely poses other daunting problems. Mars' atmospheric pressure is less than 1 percent of Earth's, making it difficult to slow a spaceship hurtling toward the surface at an estimated speed of 13,000 miles per hour. Unmanned rovers have cushioned their descents with heat shields, parachutes, and rockets, but current technology is insufficient for landing a much larger manned spacecraft, even if supplies were sent separately. "We're talking about landing perhaps a two-story house, and then another two-story house with fuel and supplies right next to it," said former NASA technologist Bobby Braun. "That's a fantastic challenge."

How far have plans progressed?

NASA teams are working on experimental projects with an eye to a possible mission to Mars and back about 25 years hence. But some in the private sector don't want to wait that long. Multimillionaire space tourist Dennis Tito has hatched a low-budget, $128 million plan to send a 50-ish married couple on a 501-day flyby that would zoom past Mars in 2018 and then use the planet's gravity to slingshot the spacecraft back to Earth. More ambitiously, the Dutch nonprofit Mars One wants to start colonizing Mars within a decade, and has already collected more than 78,000 applications from civilians willing to take a one-way trip to Mars. The group plans to select six teams of four with the necessary "intelligence, resourcefulness, courage, determination, and skill, as well as psychological stability." They would then undergo seven years of training and testing, including time in mock Mars colonies — all to be chronicled in a revenue-yielding Survivor-style television series — to make the final cut.

Would living on Mars be dangerous?

Scientists have serious concerns about the health risks of long-term exposure to radiation, reduced gravity, longer days, and extraterrestrial atmospheric conditions. Astronauts are known to experience bone degradation, muscle loss, and swollen optic nerves from spending too much time in zero gravity. A Russian-sponsored experiment called Mars 500, in which six men were confined for 500 days under conditions meant to emulate a Mars mission, showed that Mars travelers could face severe sleep disturbances, lethargy, and depression. Scientists also worry about the Martian surface's ultra-fine dust, which contains highly chlorinated salts called perchlorates that can cause respiratory problems and thyroid damage. And there's a chance, however slim, that Mars harbors potentially virulent microbes.

What would daily life on Mars be like?

Martian colonists would need a base large enough to contain comfortable, long-term living quarters and a vast array of life-support systems and supplies. They would have to construct their pressurized, air-tight habitat in phases, much the way the International Space Station was built. A secure, long-term food supply would be crucial. One company is working on 3-D printers that would combine powders and concentrates to create foods that replicate the textures, flavors, and smells of natural foods. Eventually, Martian farmers could grow food in pressurized greenhouses, using genetically modified crops to compensate for the planet's high radiation and low sunlight. Volunteers for the commercial missions say that the trade-offs in quality of life would be worth it. "I've had a deep need to explore the universe since I was a kid," said Peter Greaves, a self-employed technologist. "I envision life on Mars to be stunning, frightening, lonely, quite cramped, and busy. But my experience would be so [different] from all 6 to 7 billion human beings. That, by itself, would make up for the factors I left behind."

An insurance policy for human survival

"Single-planet species don't survive," says former astronaut John Grunsfeld. He is among the researchers, astronauts, and space exploration firms who see establishing an outpost on the Red Planet not just as a scientific challenge, but as essential to mankind's survival. Cosmologist Stephen Hawking thinks so, too. "The human race shouldn't have all its eggs in one basket, or on one planet," he says. Should nuclear proliferation, shrinking resources, a growing population, climate change, or a visit by hostile aliens threaten humankind on Earth, a colony on Mars could serve as a lifeboat to keep the species going. "I believe that we will eventually establish self-sustaining colonies on Mars and other bodies in the solar system," Hawking says. But he figures it won't happen "within the next 100 years."



Thursday, 18 July 2013

Evidence for Ancient Ocean on Mars Identfied

By Tamarra Kemsley
Jul 18, 2013 10:34 AM EDT

A possible delta on Mars where a mighty river may have once flowed into a vast ocean has been discovered by researchers at the California Institute of Technology (Caltech). (Photo : NASA)


A possible delta where a mighty river may have once flowed into a vast ocean on Mars has been discovered by researchers at the California Institute of Technology (Caltech).

This ocean, if it existed, could have covered much of Mars' northern hemisphere - stretching over as much as a third of the planet, according to the study published in the Journal of Geophysical Research. At the very least, the researchers say, the water would have covered the entire Aerolis Dorsa region, which spans about 100,000 square kilometers (60,000 square kilometers).

"Scientists have long hypothesized that the northern lowlands of Mars are a dried-up ocean bottom, but no one yet has found the smoking gun," Mike Lamb, an assistant professor of geology at Caltech and a coauthor of the paper, said in a press release.

While the new findings may not be "proof" per se of the existence of an ancient ocean, they provide some of the strongest support yet of one, according Roman DiBiase, a postdoctoral scholar at Caltech and lead author of the paper.

In order to come to their conclusion regarding the delta, the Caltech team used new high-resolution images from the Mars Reconnaissance Orbiter (MRO) to study a 100-square-kilometer area located on the possible former coastline.

Previous satellite images have shown that this area is covered in ridge-like features called inverted channels that form when coarse material, like gravel and cobbles, are carried along a river and deposited at the bottom.

After the river dries up, the finer materials erode away, leaving behind the coarser remains. This sediment then appears as today's ridge-like features, tracing the former river system.

When looked at from above, the inverted channels appear to fan out, a configuration that suggests a number of origins.

First, the channels could have once been a drainage system in which streams and creeks flowed down a mountain and converged to form a larger river.

Second, the water could have flowed in the opposite direction, creating an alluvial fan, in which a single river channel branches into multiple smaller streams and creeks.

Finally, the channels could be part of a delta, which is similar to an alluvial fan except that the smaller streams and creeks empty into a larger body of water.

To figure out which of these scenarios was most plausible, the researchers turned to satellite images taken by the HiRISE camera on the MRO.

By taking pictures from different points in its orbit, the spacecraft was able to make stereo images that allowed the scientists to determine the topography of the Martian surface. Furthermore, the HiRISE camera can pick out features as tiny as 25 centimeters long and the topographic data can distinguish changes in elevation at a resolution of 1 meter.

Using this information, the Caltech researchers analyzed the stratigraphic layers of the inverted channels, piecing together the history of how sediments were deposited along these ancient rivers and streams.

In addition, the team was able to determine the slopes of the channels back when water was still coursing through them, which in turn can reveal the direction of water flow. By doing so, they were able to narrow their options down to an alluvial fan or delta since, in this case, the water was spreading out instead of converging.

Next, the researchers were able to remove alluvial fans from their choices after they found evidence for an abrupt increase in slope of the sedimentary beds near the downstream end of the channels, suggesting that it once emptied into a large body of water.

Thus, the scientists were left with a delta as their most likely answer.

Should this be the case, it would not mark the first time scientists have discovered Martian deltas; however, most are found inside a geological boundary, like a crater. Water therefore would have most likely flowed into a lake enclosed by such a boundary and so did not provide evidence for an ocean.

This new delta, on the other hand, isn't located near any confining boundary, which suggests that the water likely emptied into a large body of water such as an ocean.

"This is probably one of the most convincing pieces of evidence of a delta in an unconfined region - and a delta points to the existence of a large body of water in the northern hemisphere of Mars," DiBiase says.

Other plausible explanations remain, such as a large confining boundary that has since been erased. For this reason, the researchers plan to continue exploring the boundary between the southern highlands and northern lowlands - the hypothetical ocean coastline - and analyze other sedimentary deposits in order to determine if they yield more evidence of an ocean.

"In our work and that of others - including the Curiosity rover - scientists are finding a rich sedimentary record on Mars that is revealing its past environments, which include rain, flowing water, rivers, deltas, and potentially oceans," Lamb says. "Both the ancient environments on Mars and the planet's sedimentary archive of these environments are turning out to be surprisingly Earth-like."



Gold on Earth formed in collision of exotic stars

Dan Vergano @dvergano , USA TODAY7:41 p.m. EDT July 17, 2013

There's gold in them thar neutron stars! That's right, astronomers claim Earth's gold, the stuff of wedding bands and pricey speaker wires, originated in cataclysmic collisions of exotic stars.



(Photo: Dana Berry)

STORY HIGHLIGHTS
A distant "gamma ray burst" spotted in June offers clues to where gold originates in the cosmos
Such high-energy bursts are thought to result from the rare collision of two exotic neutron stars
The glow left from the burst seems to confirm the production of gold occurs in the collision's aftermath

SHARECONNECT 204TWEETCOMMENTEMAILMORE

The gold glinting on your wedding band was likely born in a cataclysmic merger of two exceedingly exotic stars, astronomers report Wednesday.

Dying stars billions of years ago cooked up most of the lighter elements in the universe, the oxygen in the air and calcium of our bones, and blasted it across the cosmos in their final explosive moments.We are stardust, as the singer Joni Mitchell put it.

But some of the heaviest atoms, including gold, defied this explanation, requiring an even more exotic origin.

A team led by Harvard astronomer Edo Berger nowreports that gold is likely created as an aftereffect of the collision of two "neutron" stars. Neutron stars are themselves the collapsed remains of imploded stars, incredibly dense stellar objects that weigh at least 1.4 times as much as the sun but which are thought to be less than 10 miles wide.

While ordinary stars explode about once every century in our galaxy, Berger says, explosive collisions of two neutron stars happen only about once every 10,000 years. And it appears they spew out gold and other heavy elements in the week after their merger.

"Call it the golden glow," Berger says. "In this case, we were able to observe it for the first time and see how the merger seems to be producing (the) heavy elements."

The team bases its finding on observations of a high-energy flash of gamma rays, a "gamma ray burst" called GRB 130603B that was detected in June by NASA's Swift X-ray telescope satellite. The burst is seen as a signature of the explosive union of two neutron stars, in this case ones some 3.9 billion light-years away (one light year is about 5.9 trillion miles) the team reports in an Astrophysical Journal Letters report.

Observation of the cloudy aftereffects of the burst suggest that each merger of two neutron stars produces several moons worth of gold by weight. "At today's prices, that amount of gold would be worth 10 octillion dollars," says Berger. (That's $10,000 trillion-trillion or $10,000,000,000,000,000,000,000,000,000, for anyone counting.)

Overall about 1% of the mass of the two neutron stars was likely converted into exotic minerals by the merger, only a small part of it gold. In the collision, sub-atomic particles blasted out of the neutron stars fuse together to form heavy elements, escaping a black hole that forms afterward from the merger. Such are the likely origins for the gold that accumulated in Earth's crust some 4.54 billion years ago, swept up from space at the birth of the solar system, and now seen in jewelry store windows.

"This means (that) the Harvard team might have discovered the 'smoking gun' for unraveling the long-standing mystery which objects in the universe are responsible for the production of gold and platinum and other heavy elements," says astrophysicist Hans-Thomas Janka of Germany's Max-Planck Institute for Astrophysics."One gets even more platinum in the same events, so even more material for mankind's jewelry!"

Janka cautioned that the gamma ray burst result represents only one observation and that astronomers will need to observe more such blasts in coming years to feel fully confident about the finding.

"It really seems that the gold in jewelry that people are wearing is the result of one of the most violent explosions in the universe: a gamma-ray burst that is produced when two neutron stars merge with each other," says astrophysicist Stephen Rosswog of Germany's Jacobs University Bremen, who first suggested the golden glow effect in 1999. "These are very difficult observations, but if this turns out to be true, this would be truly very exciting news."

The news out Wednesday says the collision of neutron stars probably generated the rare minerals such as gold that spread across the universe. An artist's depiction shows a neutron star, the crushed core of a massive star that ran out of fuel and collapsed under its own weight. NASA




Wednesday, 17 July 2013

Robots will compete against one another in disaster scenarios

A new series of robots could usher in a new era of robotics.



Photo credit:

Science Recorder | Drew Adams | Wednesday, July 17, 2013



A group of robots will be competing in a series of physical trials this December in an effort to gauge whether or not they might one day replace humans in hazardous situations.

What once was considered a favored staple of science fiction is now on the way to becoming a reality as the Defense Advanced Research Projects Agency, or DARPA, spearheads its Robotics Challenge from December 20 – 21. The competition consists of various obstacle courses that will test the limits of the robotic representatives via disaster response operations. The winning team will receive $2 million.

The Robotics Challenge website claims that “The goal of the DARPA Robotics Challenge (DRC) is to generate groundbreaking research and development so that future robotics can perform the most hazardous activities in future disaster response operations, in tandem with their human counterparts, in order to reduce casualties, avoid further destruction, and save lives.”

Six Track A customized robots will compete in the trials, including the Korea Advanced Institute of Science and Technology and Rainbow Co. developed HUBO. The current version of the humanoid machine, DRC-HUBO, will be operated by a team led by Drexel University. The other competing bots include CHIMP (Carnegie-Mellon University’s National Robotics Engineering Center), RoboSimian (NASA’s Jet Propulsion Lab), T.H.O.R. (Virginia Tech), Valkyrie (NASA’s Johnson Space Center), and a HRP-2 based robot from Japan’s SCHAFT Inc.

July 11 unveiled the Atlas robot as well, a 6-foot-2, 330 pound humanoid machine that will be used by seven Track B/C teams as they train for the December trials. Atlas was developed by Boston Dynamics and is considered one of the most advanced humanoid robots to date. It consists of a hydraulic powering system and two sets of hands that were developed by both Sandia National Labs and iRobot.

The seven Track B/C teams won the use of Atlas by progressing through DARPA’s Virtual Robotics Challenge in June. The challenge, which was the first part of DARA’s overall initiative, consisted of groups directing a virtual avatar of Atlas through computer simulated environments.

“[T]he software algorithms that were successfully employed by teams in the VRC should transfer with minor tuning to the ATLAS hardware,” stated a press release from DARPA.

Program manager for the challenge Gill Pratt elaborated further: “The Virtual Robotics Challenge was a proving ground for teams’ ability to create software to control a robot in a hypothetical scenario. The DRC Simulator tasks were fairly accurate representations of real world causes and effects, but the experience wasn’t quite the same as handling an actual, physical robot.”

A fourth track will be open to an unspecified, unfunded number of robot competitors. The event will be open to the public.

Tuesday, 16 July 2013

Nasa's Hubble telescope discovers new Neptune moon

15 July 2013 Last updated at 23:30 GMT


Voyager failed to spot the tiny moon during its 1989 fly-pass


The Hubble space telescope has discovered a new moon orbiting Neptune, Nasa has confirmed.

Designated S/2004 N 1, this is the 14th known moon to circle the giant planet.

It also appears to be the smallest moon in the Neptunian system, measuring just 20 km (12 miles) across, completing one revolution around Neptune every 23 hours.

US astronomer Mark Showalter spotted the tiny dot while studying segments of rings around Neptune.

Nasa said the moon was roughly 100 million times dimmer than the faintest star visible to the naked eye.

It is so small that the Voyager spacecraft failed to spot it in 1989 when it passed close by Neptune and surveyed the planet's system of moons and rings.

Mr Showalter's method of discovery involved tracking the movement of a white fleck appearing over and over again in more than 150 photographs taken of Neptune by Hubble between 2004 and 2009.

"The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system," Mr Showalter explained.

"It's the same reason a sports photographer tracks a running athlete - the athlete stays in focus, but the background blurs."



Chemical reaction levitated by sound

16 July 2013 Last updated at 14:02 GMT

By Victoria GillScience reporter, BBC News
The water droplet and sodium particle appear to dance between the platforms



Scientists in Switzerland have designed an acoustic levitator capable of mixing substances as they hover.

The device is built of two sound-emitting platforms that trap the substances between them.

Sound waves move upward until they are reflected by the platform above. The upward- and downward-moving waves overlap, reinforcing each other in places and cancelling out in others. This traps materials in place.

The development is described in PNAS.
The researchers managed to levitate a toothpick on their acoustic squares

To demonstrate its capabilities, the researchers used it to mix a single drop of water with a single coffee grain and to bring together a minuscule grain of sodium metal with a drop of water, causing a tiny but explosive reaction. They even managed the levitate a toothpick.

Their device though needs to use very powerful sound waves to levitate even these very small droplets and particles.

Lead researcher Daniele Foresti from the Swiss Federal Institute of Technology (ETH) in Zurich, explained that to "cancel out gravity" in this way required 160 decibels of sound - higher than the 120 decibels you would hear if you stood a metre (3ft) away from a rocket launch.

"That's why we use ultrasound," Dr Foresti said.

"[Using frequencies beyond those that human ears can detect] means we won't hear it, so we can work with without any ear protection."Rocket launch

Acoustic levitators were invented in the 1980s by Nasa scientists looking for ways to simulate weightlessness. But this diminutive device is the first to be able to move and control the material it levitates.

"We have total control of the acoustic field inside," Dr Foresti said.

By making the acoustic platform of many tiny squares - each 15mm x 15mm square being its own sound-emitting device - the researchers are able to "pass" a ball of material from one of these platforms to another.

The main benefit of this remotely controlled chemical reaction is that it is contactless, meaning chemical tests could be carried out without any possibility of contamination.

"One of the tests we would like to perform is DNA transfection," said Dr Foresti.

This is the process of introducing DNA into a cell, which is a medically useful process but one that is very sensitive to contamination.

"Some of the transfection agents [chemical substances needed to carry DNA into cells] can be rendered ineffective even by plastics," said Dr Foresti,

"So this could be a way to overcome that problem."


NASA scientists see the heart of space weather in action

Magnetic reconnection occurs when magnetic field lines come together, break apart, and then exchange partners, snapping into place with a bolt of energy



Photo credit: NASA/SDO/RHESSI/Goddard


Science Recorder | Ellen Miller | Tuesday, July 16, 2013


Two spacecraft have captured a video of a magnificent explosion on the Sun called magnetic reconnection. Magnetic reconnection lies at the heart of explosions that occur on the surface of the Sun, a press release from NASA explains.

Magnetic reconnection occurs when magnetic field lines come together, break apart, and then exchange partners, snapping into place with a bolt of energy. Scientists at space research agencies such as NASA are seeking to better understand phenomena like magnetic reconnection because they hope that it will aide them in understanding and predicting space weather, which can affect satellites and radio communication. Because magnetic fields are invisible, it can be difficult to observe them in action.

Yang Su, a solar scientist at the University of Graz in Austria, explains that scientists are specifically seeking to understand how magnetic reconnection can cause solar flares. Scientists use computer modeling and a few observations about magnetic reconnection to try to understand this concept, but thanks to new video from two spacecraft, they will be able to take a more in-depth look at magnetic reconnection. Su discovered direct images of magnetic reconnection while looking through data from the Solar Dynamics Observatory. While a few images have been discovered before, this is the first comprehensive set that will really aide scientists in understanding what is happening when magnetic reconnection occurs and how it impacts solar and space weather.


While magnetic field lines are invisible, they force charged particles of plasma along their lengths, making them visible in images. Space telescopes pick up the lines as they arch and move along the frame of the lens. Su observed two bundles of lines move towards each other and then disconnect and reconnect.

The video offers scientists an entirely new resource since it allows them to see the phenomena in recorded time and animated, as opposed to simple photos that only offer an indication of what is happening. The team, led by Su, turned to the Reuven Ramaty High Energy Solar Spectroscopic Imager, known as RHESSI, to confirm that they were actually observing magnetic reconnection in action. RHESSI shows where hot pockets are, indicating where space weather is occurring. By combining the data, scientists were able to describe the entire process of magnetic reconnection, confirming many theories about the process as well as learning new information that they were able to observe for the first time.

Magnetic reconnection does not only occur on the surface of the sun, it also occurs near stars and within Earth’s own magnetic field, making it a key player in space weather patterns.




Read more: http://www.sciencerecorder.com/news/nasa-scientists-see-the-heart-of-space-weather-in-action/#ixzz2ZDyV86sf