Giant Breach in Earth’s Magnetic Field Discovered
Dec. 16, 2008: NASA’s five THEMIS spacecraft have discovered a breach in Earth’s magnetic field ten times larger than anything previously thought to exist. Solar wind can flow in through the opening to “load up" the magnetosphere for powerful geomagnetic storms. But the breach itself is not the biggest surprise. Researchers are even more amazed at the strange and unexpected way it forms, overturning long-held ideas of space physics.
“At first I didn’t believe it," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. “This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction."
The magnetosphere is a bubble of magnetism that surrounds Earth and protects us from solar wind. Exploring the bubble is a key goal of the THEMIS mission, launched in February 2007. The big discovery came on June 3, 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance.
Right: One of the THEMIS probes exploring the space around Earth, an artist’s concept. [more]
“The opening was huge—four times wider than Earth itself," says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data. Li’s colleague Jimmy Raeder, also of New Hampshire, says “1027 particles per second were flowing into the magnetosphere—that’s a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."
The event began with little warning when a gentle gust of solar wind delivered a bundle of magnetic fields from the Sun to Earth. Like an octopus wrapping its tentacles around a big clam, solar magnetic fields draped themselves around the magnetosphere and cracked it open. The cracking was accomplished by means of a process called “magnetic reconnection." High above Earth’s poles, solar and terrestrial magnetic fields linked up (reconnected) to form conduits for solar wind. Conduits over the Arctic and Antarctic quickly expanded; within minutes they overlapped over Earth’s equator to create the biggest magnetic breach ever recorded by Earth-orbiting spacecraft.
Above: A computer model of solar wind flowing around Earth’s magnetic field on June 3, 2007. Background colors represent solar wind density; red is high density, blue is low. Solid black lines trace the outer boundaries of Earth’s magnetic field. Note the layer of relatively dense material beneath the tips of the white arrows; that is solar wind entering Earth’s magnetic field through the breach. Credit: Jimmy Raeder/UNH. [larger image]
The size of the breach took researchers by surprise. “We’ve seen things like this before," says Raeder, “but never on such a large scale. The entire day-side of the magnetosphere was open to the solar wind."
The circumstances were even more surprising. Space physicists have long believed that holes in Earth’s magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north.
“To the lay person, this may sound like a quibble, but to a space physicist, it is almost seismic," says Sibeck. “When I tell my colleagues, most react with skepticism, as if I’m trying to convince them that the sun rises in the west."
Here is why they can’t believe their ears: The solar wind presses against Earth’s magnetosphere almost directly above the equator where our planet’s magnetic field points north. Suppose a bundle of solar magnetism comes along, and it points north, too. The two fields should reinforce one another, strengthening Earth’s magnetic defenses and slamming the door shut on the solar wind. In the language of space physics, a north-pointing solar magnetic field is called a “northern IMF" and it is synonymous with shields up!
“So, you can imagine our surprise when a northern IMF came along and shields went down instead," says Sibeck. “This completely overturns our understanding of things."
Northern IMF events don’t actually trigger geomagnetic storms, notes Raeder, but they do set the stage for storms by loading the magnetosphere with plasma. A loaded magnetosphere is primed for auroras, power outages, and other disturbances that can result when, say, a CME (coronal mass ejection) hits.
The years ahead could be especially lively. Raeder explains: “We’re entering Solar Cycle 24. For reasons not fully understood, CMEs in even-numbered solar cycles (like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME should open a breach and load the magnetosphere with plasma just before the storm gets underway. It’s the perfect sequence for a really big event."
Sibeck agrees. “This could result in stronger geomagnetic storms than we have seen in many years."
more information What happened to conventional wisdom? Researchers at the University of New Hampshire are using computer models to unravel the basic physics of the great breach. They’re finding that reconnection at the poles is key. Conventional wisdom held that equatorial reconnection was more important, which is why the giant breaches were not anticipated until THEMIS flew through one.View a video version of this story.
more stories about THEMIS:
Magnetic Portals Connect Sun and Earth — Science@NASA
Plasma Bullets Spark Northern Lights — Science@NASA
NASA Spacecraft Make New Discoveries about Northern Lights — Science@NASA
THEMIS, short for Time History of Events and Macroscale Interactions during Substorms, is the fifth medium-class mission under NASA’s Explorer Program. The program, managed by The Explorers Program Office at Goddard Space Flight Center, Greenbelt, Md., provides frequent flight opportunities for world-class space investigations in Heliophysics and Astrophysics. The University of California, Berkeley’s Space Sciences Laboratory managed the project development and is currently operating the THEMIS mission. Swales Aerospace, Beltsville, Md., built the THEMIS satellites.
NASA’s Future:US Space Exploration Policy
No birds, just bees. Photograph: Graeme Robertson for the Guardian
In the past six years, more than 10m beehives have been wiped out from a mystery disease called colony collapse disorder. This destruction has serious implications on worldwide ecology and economy.
Of the 100 crop species responsible for providing 90% of food worldwide, 71 are dependent on bee pollination, according to UN estimates (pdf). It’s difficult to pinpoint the financial implications of this destruction, but the international body says pollination is worth between $37bn and $91bn, annually.
Stories about the declining population and its effect on the environment trickle through the news cycle each week. To bring awareness to these stories and contextualize the issues, we will highlight the major bee-related stories every Tuesday, with analysis from The Guardian’s Alison Benjamin, co-author of A World Without Bees, Bees in the City: The Urban Beekeepers’ Handbook and Keeping Bees and Making Honey. She is also a beekeeper.
Bees pollinating crops including watermelon, cucumbers and blueberries return to their hives with pollen contaminated by agricultural chemicals – leaving insects more susceptible to a lethal parasite, according to a study published online last week. Pollen filled with fungicides, insecticides and other agriculture chemicals was fed to healthy bees, that were then more likely to be infected by Nosema ceranae – the parasite linked to the decimation of honey bees.
Fungicides, which we didn’t expect to harm insects, seem to have a sub-lethal effect on bee health," Dennis vanEngelsdorp, an entomologist at the University of Maryland and senior author of the new study, told NBC News. He said this is important because fungicides aren’t heavily regulated.
Why it matters:
Colony collapse disorder is caused by a combination of factors – parasites, agricultural chemicals and poor nutrition. These all weaken the honeybees’ immune system and make them more susceptible to viruses and infections that can kill them. Up until now concerns around agricultural chemicals and honeybees have focused on the impact neonicotinoid pesticides are having and a temporary ban has been imposed on three types by the European Commission. Yet, this study shows that fungicides used on many crops pollinated by bees can also have serious consequences. Attention now needs to turn to these chemicals and to ensure that tests are conducted when they are registered for use which protects honeybees.
The fact that different kinds of bees prefer different kinds of flowers lead two researchers in Colorado to wonder what would happen if an entire bee species disappeared. So they removed (using nets and traps) the most numerous bumble bee species from a meadow in Colorado. The question: would the other bee species pick up the slack and continue to pollinate the abandoned flowers? Or would they leave the plants to die?
The result: the remaining bumblebees became less faithful to one flower species than they had been before the more populous bees had been around to keep them in line. This had a serious impact on the tall larkspur, a lovely purple wildflower, who needs its own pollen to reproduce (aka a faithful bee partner).
Because of the unfaithful bees, the researchers reported Monday in Proceedings of the National Academy of Sciences, plants produced about 30% less seed. The finding, they report, shows a surprising effect from a loss of biodiversity that could have implications for a variety of ecosystems.
Why it matters:
It is not just honeybees that pollinate crops and flowers, bumblebees and solitary bees do too. And there are many more varieties of bumblebees and solitary bees than there are honeybees. In fact we only have one species of honeybee in the US and Europe and Australasia – Apis Mellifera; the western honeybee. Many bumblebees and solitary bees have evolved to pollinate certain flowers. They have a symbiotic relationship – the flower needs the bee to pollinate it and the bee needs the nectar and pollen from the flower to provide protein and energy for itself and the baby bees. If the bee dies out that flower will soon follow and the ecosystems fall apart.
We don’t keep bumblebees and solitary bees, but we can do things to improve their habitat from creating bee hotels – a collection of hollow plant stems – where solitary bees can lay their eggs to leaving a pile of leaves in the garden where bumblebees can nest.
We hit peak bee crisis this week when Martha Stewart, queen of domestic perfection, started tending to her own bee hives and coaching readers on how to take care of their own.
With the epidemic hive failures and disappearance of many colonies, beekeepers have new concerns about maintaining their hives. In fact, Martha’s own colony has experienced a collapse over the years as her own bees left in a “mass exodus," and she had to re-establish much of the colony within her four hives, prompting her to send out her message to all other would-be keepers out there.
Why it matters:
The decline in honeybees has led to an unprecedented surge in the number of new beekeepers around the globe. It has become very fashionable for young, urban professionals to keep bees on roof tops and backyards. But beekeeping is a perilous pastime because bees can die during the winter of starvation, or they can be overrun with the varroa parasite if not treated correctly. It can be expensive restocking your hive every spring. Probably a more effective way to save honeybees and other bees is to make your neighbourhood more bee-friendly by planting bee-friendly flowers and trees in your garden and in your parks and streets – bees need flowers throughout the year, from very early spring to late autumn – ditching any weed killers which can include harmful chemicals, and replacing driveways and decking with wildflowers.
When bees become disruptive in cities, local governments are favoring the relocation of bees over extermination. This specialized process requires beekeepers and bee specialists to transport tens of thousands of bees to farms – in this instance Rodney Oakley moved 30,000 bees, the amount typically found in a small hive, in Austin, Texas. He told the Austin American Statesman that local honey bees struggle from the mix of drought conditions, increased used of pesticides and decreased diversity in crops.
As more attention has been focused on the honey bee and its importance and decline, more people have been calling," Rodney Oakley said. “In communities that are more conscious of environmental issues, like Austin, they will search me out so that the bees aren’t destroyed.
Why it matters:
Honeybees are important for pollination and to make delicious honey, so it’s never a good idea to kill bees. They can live in harmony with people in urban areas if the beekeeper is responsible and ensures his bees don’t swarm and annoy the neighbours. But if there are problems with the neighbours you should relocate your honeybees. And if you see a swarm of bees, you should contact a local beekeeping association or group. They will have a designated swarm collector who will come out and collect the bees and take them away.
UK government scientist Dr Helen Thomspon is set to join chemical giant Syngenta. Thompson’s research – including a field trial of neonicotinoids, the frequently used insecticide, on bees – was used by ministers to argue against a ban on pesticides.
UK government policy should be informed by unbiased and disinterested scientific research," said Joan Walley MP, chair of the environmental audit committee, whose report in April accused the environment secretary Owen Paterson’s department of “extraordinary complacency" over bees and pesticides. “This principle is undermined if the government research agency is too close to the pesticides industry and if scientists are zigzagging between the two.
Why it matters:
There has been huge controversy over the UK government’s stance against banning certain pesticides implicated in bee deaths across the globe. The ban was introduced earlier this year Europe-wide despite the UK government’s resistance. Environmental groups have accused the government of being too close to big agricultural companies such as Syngenta. Whether this is true or not, Dr Helen Thompson’s move from government scientist to Syngenta does not inspire confidence that this government was acting in an impartial manner. What of other government scientists – are they too looking for very well paid jobs with the chemical giants? If so are they likely to be providing advice that is critical of their potential future employers?
The Mystery of Bee Colony CollapseT.J. Gehling/Flickr
What’s tipping honeybee populations into huge annual die-offs? For years, a growing body of evidence has pointed to a group of insecticides called neonicotinoids, widely used on corn, soy, and other US crops, as a possible cause of what has become known as colony collapse disorder (CCD).
Rather than kill bees directly like, say, Raid kills cockroaches, these pesticides are suspected of having what scientists call “sub-lethal effects"—that is, they make bees more vulnerable to other stressors, like poor nutrition and pathogens. In response to these concerns, the European Union recently suspended most use for two years; the US Environmental Protection Agency, by contrast, still allows them pending more study.
But according to a new peer-reviewed paper, neonicotinoids aren’t the only pesticides that might be undermining bee health. The study, published in PLOS One and co-authored by a team including US Department of Agriculture bee scientist Jeff Pettis and University of Maryland entomologist Dennis vanEngelsdorp, found that a pair of widely used fungicides are showing up prominently in bee pollen—and appear to be making bees significantly more likely to succumb to a fungal pathogen, called Nosema ceranae, that has been closely linked to CCD. The finding is notable, the authors state, because fungicides have so far been “typically seen as fairly safe for honey bees."