A cloud of cold, charged gas around Earth, called the plasmasphere and seen here in purple, interacts with the particles in Earth's radiation belts — shown in grey— to create an impenetrable barrier that blocks the fastest electrons from moving in closer to our planet.
Image Credit: NASA/Goddard
The Van Allen belts are a collection of charged particles, gathered in place by Earth’s magnetic field. They can wax and wane in response to incoming energy from the sun, sometimes swelling up enough to expose satellites in low-Earth orbit to damaging radiation. The discovery of the drain that acts as a barrier within the belts was made using NASA's Van Allen Probes, launched in August 2012 to study the region. A paper on these results appeared in the Nov. 27, 2014, issue of Nature magazine.
“This barrier for the ultra-fast electrons is a remarkable feature of the belts," said Dan Baker, a space scientist at the University of Colorado in Boulder and first author of the paper. "We're able to study it for the first time, because we never had such accurate measurements of these high-energy electrons before."
Understanding what gives the radiation belts their shape and what can affect the way they swell or shrink helps scientists predict the onset of those changes. Such predictions can help scientists protect satellites in the area from the radiation.
The Van Allen belts were the first discovery of the space age, measured with the launch of a US satellite, Explorer 1, in 1958. In the decades since, scientists have learned that the size of the two belts can change – or merge, or even separate into three belts occasionally. But generally the inner belt stretches from 400 to 6,000 miles above Earth's surface and the outer belt stretches from 8,400 to 36,000 miles above Earth's surface.
A slot of fairly empty space typically separates the belts. But, what keeps them separate? Why is there a region in between the belts with no electrons?
Enter the newly discovered barrier. The Van Allen Probes data show that the inner edge of the outer belt is, in fact, highly pronounced. For the fastest, highest-energy electrons, this edge is a sharp boundary that, under normal circumstances, the electrons simply cannot penetrate.
"When you look at really energetic electrons, they can only come to within a certain distance from Earth," said Shri Kanekal, the deputy mission scientist for the Van Allen Probes at NASA's Goddard Space Flight Center in Greenbelt, Maryland and a co-author on the Nature paper. "This is completely new. We certainly didn't expect that."
The team looked at possible causes. They determined that human-generated transmissions were not the cause of the barrier. They also looked at physical causes. Could the very shape of the magnetic field surrounding Earth cause the boundary? Scientists studied but eliminated that possibility. What about the presence of other space particles? This appears to be a more likely cause.
This animated gif shows how particles move through Earth’s radiation belts, the large donuts around Earth. The sphere in the middle shows a cloud of colder material called the plasmasphere. New research shows that the plasmasphere helps keep fast electrons from the radiation belts away from Earth.
The radiation belts are not the only particle structures surrounding Earth. A giant cloud of relatively cool, charged particles called the plasmasphere fills the outermost region of Earth's atmosphere, beginning at about 600 miles up and extending partially into the outer Van Allen belt. The particles at the outer boundary of the plasmasphere cause particles in the outer radiation belt to scatter, removing them from the belt.
This scattering effect is fairly weak and might not be enough to keep the electrons at the boundary in place, except for a quirk of geometry: The radiation belt electrons move incredibly quickly, but not toward Earth. Instead, they move in giant loops around Earth. The Van Allen Probes data show that in the direction toward Earth, the most energetic electrons have very little motion at all – just a gentle, slow drift that occurs over the course of months. This is a movement so slow and weak that it can be rebuffed by the scattering caused by the plasmasphere.
This also helps explain why – under extreme conditions, when an especially strong solar wind or a giant solar eruption such as a coronal mass ejection sends clouds of material into near-Earth space – the electrons from the outer belt can be pushed into the usually-empty slot region between the belts.
"The scattering due to the plasmapause is strong enough to create a wall at the inner edge of the outer Van Allen Belt," said Baker. "But a strong solar wind event causes the plasmasphere boundary to move inward."
A massive inflow of matter from the sun can erode the outer plasmasphere, moving its boundaries inward and allowing electrons from the radiation belts the room to move further inward too.
The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, built and operates the Van Allen Probes for NASA's Science Mission Directorate. The mission is the second in NASA's Living With a Star program, managed by Goddard.
For more information about the Van Allen Probe, visit:
Currently, the largest and most powerful helicopter to have ever entered production is the gargantuan Mi-26 'Halo' of Russian origin, of which many still serve in governmental and commercial roles around the globe. After decades of the 'Halo' being on top, a new record holder is now said to be on the way, with Russia and China joining forces to make it happen.
Cockpit of the highly modernized Mi-26T2, currently the most powerful and largest helicopter in the world.
This new super-heavy lift class chopper was originally thought to be an outgrowth of the existing, all-weather capable and highly modernized Mi-26T2, but now it seems that it will only borrow a few elements from it, and will overwhelmingly be a 'clean sheet' design.
The fresh design approach is due to China's eye popping requirements. According to Russia, they are said to include almost twice the lifting capacity of the already freakishly powerful and huge Mi-26. That would put the new chopper's lifting ability at somewhere around 80,000lbs! In comparison, the CH-53K 'King Stallion,' America's latest heavy lift design, has a total gross weight just slightly above that figure at 88,000lbs.
You heard that right, this new Russian-Chinese super chopper is aiming to be able to lift roughly the equivalent of America's newest heavy-lift chopper in its entirety, at its maximum gross weight. That is one powerful helicopter.
Originally, this new Russian-Chinese design was thought to be an outgrowth of the Mi-26T2, although this is now inaccurate as Chinese performance demands are far outside any existing designs' theoretical capabilities.
The Mi-26 can already haul vehicles that are larger than what can fit even into a C-130 Hercules, including everything from armored personnel carriers to dump trucks. Yet China has had a uniquely large demand for heavy under-slung cargo carrying ability, for both construction and logistical purposes and there has been talk for the last decade or two about how a super-heavy lift helicopter could change the way some structures are built. This is especially true for modular vertical oriented structures that are intended to be built fast and replicated quickly, an area of architecture and construction that China continues to be the leader in.
Just part of the massive cargo hold of the Mi-26T2. The aircraft has been nicknamed the 'flying office building' for a reason.
According to Russian reports, multiple Chinese agencies are part of this new mega-chopper procurement program, including those that deal with emergency management and response. This makes some sense as during a natural disaster, or even a time of conflict, moving massive amounts of supplies quickly will be all that much more critical considering China's massive population.
Mi-26 lifting a stricken CH-47 in Afghanistan:
The only other helicopter ever flown that could lift anything in the weight class that China is looking for was also of Russian origin: the colossal Mil V-12. Only two prototypes were built and test flown in the late 1960s, and the design used a unique parallel/traverse rotor, quad-engine layout. At first, the aircraft almost tore itself apart during testing, but later, the second prototype was seen widely as a successful, although uneconomic design.
The V-12 was built to haul close to close to 100k lbs, although normal missions were thought to see the super-chopper carry about 85,000lbs, with lighter loads being carried over increasingly longer distances.
The V-12 was never put into series production because its intended mission, to deploy ballistic missiles around the vastness of the Russian countryside, was not a priority by the time the design was mature. It is not clear if Russia plans on reviving similar design elements of the V12 program to meet China's high, or should I say heavy, vertical lift aspirations.
A cost has not been publicly assigned to the program, nor has there been word regarding what percentage Russia will share in the costs of developing such an exotic machine. Regardless of the public absence of some details, Russia says this new design requirements will be locked by the first quarter of 2015.
Ever since the dawn of cloning technology, people have dreamed about bringing an extinct species back to life, and now a South Korean company is claiming it could bring back the woolly mammoth in a few decades’ time, according to Live Science reporter Tia Ghose.
Insung Hwang, a geneticist at the South Korean company Sooam, said the discovery of a mostly-intact mammoth in 2013 has opened the door to bringing the species back.
“We’re trying hard to make this possible within our generation,” he said recently, reports Tristan Kirk of The Telegraph.
However, just because science has the capability to bring back a woolly mammoth doesn’t mean we should – according to some scientists concerned about the ethics of such a Frankenstein-esque procedure.
Tori Herridge, a paleobiologist and mammoth specialist at the Natural History Museum in London, told Kirk that a female elephant would have to act as a surrogate mother and the birthing process isn’t without its dangers for the elephant. Also, once the mammoth is born – it could potentially live out a lonely captive existence in a world it may not be evolved to deal with.
“The most fundamental step and ethical concern with this kind of procedure is that you need to have an Asian elephant surrogate mum at some point,” Herridge told the telegraph reporter. “Cloning a mammoth will require you to experiment on probably many, many Asian elephants.”
“I don’t think they are worth it – the reasons just aren’t there,” she added.
The 2013 mammoth was found in a remote part of Siberia, Ghose reports. Upon discovery and inspection, the animal carcass began to ooze a deep red liquid thought to be mammoth blood. The carcass was apparently so well-preserved – one scientist actually took a bite out of its meat.
The specimen, dubbed Buttercup, was eventually transferred to a Russian research center, where it was inspected and eventually refrozen to prevent decomposition. Tests would later reveal that blood cells in the red liquid were broken, but still held hemoglobin – an iron-rich chemical that stores oxygen. Researchers haven’t revealed the presence of a complete mammoth genome, meaning cloning the animal is still a theory for now.
Scientists suspect that mammoths were social creatures and therefore cloning one or two might be seen as placing these animals into an unnatural and cruel existence.
“There is no good reason to clone mammoths and many reasons not to, including forcing elephants to carry young,” Jack Ashby, the manager of Grant Museum of Zoology at University College London, recently posted on Twitter.
Scientists from the South Korean company have said that their method would take a long time to work out based on the current state of affairs – leaving plenty of time for the debate over cloning extinct species to rage on.
Sir Ian Wilmut, the Edinburgh-based professor who cloned the world’s first animal, said bringing back the woolly mammoth would be worth the effort.
“I think it should be done as long as we can provide great care for the animal,” he said last year. “If there are reasonable prospects of them being healthy, we should do it. We can learn a lot about them.”