El masaje ayuda contra la depresion

NEW YORK (Reuters Health) - Massage therapy may help relieve symptoms of depression, a new review of the medical literature hints.

Health

The authors of the review, however, acknowledge difficulties with research on the effects of massage, including the fact that it's impossible to "blind" study participants or care providers to whether a person is receiving massage or a comparison treatment.

Nevertheless, they say there is "good evidence to suggest that massage therapy is an effective treatment of depression."

Depression is a huge public health problem, and treatment is often inadequate, Dr. Wen-Hsuan Hou of I-Shou University in Kaohsiung, Taiwan and colleagues note in their report.

While massage can ease stress and tension and may have emotional benefits, the use of massage therapy in depressed patients is "controversial," the investigators note, and "there is no qualitative review of the treatment effect of massage therapy in depressed patients."

To investigate further, they searched for randomized controlled trials of massage therapy in depressed patients. They identified 17 studies including 786 people in all. In 13 of the trials, massage therapy was compared to another active treatment such as Chinese herbs, relaxation exercises, or rest, while four compared massage to a "no treatment" control group. Investigators also used a range of methods for evaluating mood and depression in study participants.

Overall, the studies, which were of "moderate" quality, showed that massage therapy had "potentially significant effects" in alleviating symptoms of depression, the researchers report in the American Journal of Psychiatry.

It's not clear from the analysis, they emphasize, whether a person would need to undergo regular massage therapy for benefits to persist.

There are a number of ways through which massage could help people with depression, the researchers note, for example, by reducing stress and inducing relaxation; building an "alliance" between the therapist and patient; and by causing the body to release the "trust hormone" oxytocin.

"Further well-designed and longer follow-up studies, including accurate outcome measures, are needed," they conclude.

SOURCE: Journal of Clinical Psychiatry, online March 23, 2010.

Para los fanaticos del chocolate

Chocolate 'can cut blood pressure and help heart'

Easter eggs may not be so bad for you after all, if you eat just a little


Easter eggs and other chocolate can be good for you, as long as you eat only small amounts, latest research suggests.

The study of over 19,000 people, published in the European Heart Journal, found those who ate half a bar a week had lower blood pressure.

They also had a 39% lower risk of heart attacks and strokes.

Heart campaigners warned that too much chocolate is damaging because it has a lot of calories and saturated fat.

The study looked at the chocolate consumption of middle-aged men and women over eight years.

It compared the health of those who ate the most and least chocolate. Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense food
Dr Brian Buijsse, study author


The difference between these two groups was just 6 grams a day, equivalent to one small square of chocolate a day.

The lead author, Dr Brian Buijsse, from the German Institute of Human Nutrition, Nuthetal said: "Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, therefore chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke."

This is, in fact, what the study found. Those who ate more chocolate cut their risk of heart attacks by around a quarter, and of stroke by nearly half, compared with those who ate the least.

Chocolate lovers dream

But Dr Buijsse warned that it was important people ensured that eating chocolate did not increase their overall intake of calories or reduce their consumption of healthy foods.

"Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense food, such as snacks, in order to keep body weight stable," he said.

The researchers believe that flavanols in cocoa may be the reason why chocolate seems to be good for people's blood pressure and heart health.

And since there is more cocoa in dark chocolate, dark chocolate may have a greater effect.

Heart campaigners warned that chocolate is still bad for you if you eat too much.

Victoria Taylor, Senior Heart Health Dietician, at the British Heart Foundation said: "This sounds like a dream for chocolate lovers and just in time for Easter too, but it's important to read the small print with this study.

"The amounts consumed on average by even the highest consumers was about one square of chocolate a day or half a small chocolate Easter egg in a week, so the benefits were associated with a fairly small amount of chocolate.

"Some people will be tempted to eat more than one square, however, chocolate has high amounts of calories and saturated fat which are linked to weight gain and raised cholesterol levels. Two of the key risk factors for heart disease."

'Radio-Active' Sunspot

Space Weather News for March 29, 2010
http://spaceweather.com

"RADIO-ACTIVE" SUNSPOT:  Over the weekend, big sunspot 1057 emitted a series of radio bursts that caused roaring sounds to issue from the loudspeakers of shortwave receivers.  Visit today's edition of http://spaceweather.com to hear a sample "roar" and to find out how you can build your own solar radio burst monitor.

FIRST FULL MOON OF NORTHERN SPRING: According to folklore, tonight's full Moon has a special name--the Worm Moon. It signals the coming of northern spring, a thawing of the soil, and the first stirrings of earthworms in long-dormant gardens. Step outside tonight and behold the wakening landscape. "Worm moonlight" is prettier than it sounds.

SHUTTLE SIGHTINGS:  Space shuttle Discovery is set to launch to the International Space Station on April 5th.   During the 13-day mission, the two spaceships will make a series of bright flybys over North America.  Check the Simple Satellite Tracker for viewing opportunities: http://spaceweather.com/flybys.  And don't forget, there's an app for that, too:  http://simpleflybys.com


 

Mas beneficios del Omega-3

Omega-3 May Reduce Endometriosis Risk
But trans fats could increase it, researchers say


WEDNESDAY, March 24 (HealthDay News) -- Women who consume high levels of trans fats have a 48 percent increased risk of endometriosis, while those who eat diets rich in omega-3 oils are 22 percent less likely to develop the condition, a new study finds.

In endometriosis, pieces of the womb lining (endometrium) are found outside of the womb. Some women experience no symptoms, but many suffer severe pain. The condition, which can lead to infertility, affects about 10 percent of women. Treatments include pain medication, hormone drugs or surgery.

In this study, researchers analyzed dietary and other data from almost 71,000 women enrolled in the U.S. Nurses Health Study. Over 12 years of follow-up, 1,199 participants were diagnosed with endometriosis. The researchers said their results suggest that diet may be an important factor in the development of the condition.

The study is published March 24 in the journal Human Reproduction.

"Millions of women worldwide suffer from endometriosis. Many women have been searching for something they can actually do for themselves, or their daughters, to reduce the risk of developing the disease, and these findings suggest that dietary changes may be something they can do," study leader Dr. Stacey Missmer, an assistant professor of obstetrics, gynecology and reproductive biology at Brigham and Women's Hospital and Harvard Medical School in Boston, said in a news release.

"The results need to be confirmed by further research, but this study gives us a strong indication that we're on the right track in identifying food rich in omega-3 oils as protective for endometriosis and trans fats as detrimental," she said.

Long-chain omega-3 fatty acids, which have been linked to reduced heart disease risk, are found mostly in oily fish. Trans fats, which increase heart disease risk, are used in thousands of processed foods.

More information

The National Women's Health Information Center has more about endometriosis.



-- Robert Preidt



SOURCE: Human Reproduction, news release, March 23, 2010

Satanicos en el vaticano

Spanish Exorcist Addresses Claims of Satanic Influence in Vatican

3/3/2010

Catholic News Agency (www.catholicnewsagency.com)

In a book of memoirs the noted Italian exorcist Fr. Gabriele Amorth affirmed 'Yes, also in the Vatican there are members of Satanic sects.'

Frs. Jose Fortea and Gabriel Amorth.

ROME (CNA) - A renowned exorcist in Rome recently released a book of memoirs in which he declares to know of the existence of Satanic sects in the Vatican where participation reaches all the way to the College of Cardinals. A second demonologist, also residing in Rome, entered the debate this week, clarifying the origins of the information and defending the Vatican's clergy as an "edifying and virtuous" collection of prelates.

In a book of memoirs released in February, the noted Italian exorcist Fr. Gabriele Amorth affirmed that "Yes, also in the Vatican there are members of Satanic sects." When asked if members of the clergy are involved or if this is within the lay community, he responded, "There are priests, monsignors and also cardinals!"

The book, "Father Amorth. Memoirs of an Exorcist. My life fighting against Satan." was written by Marco Tosatti, who compiled it from interviews with the priest.

Fr. Amorth was asked by Tosatti how he knows Vatican clergy are involved. He answered, "I know from those who have been able to relate it to me because they had a way of knowing directly. And it's something 'confessed' most times by the very demon under obedience during the exorcisms."

The famous Italian exorcist was also asked if the Pope was aware of Satanic sects in the Vatican, to which Fr. Amorth replied, "Of course, he was informed. But he does what he can. It's a horrifying thing."

Benedict XVI, being German, comes from a place "decidedly averse to these things," argued Fr. Amorth, saying that in Germany "there practically aren't any exorcists." However, he clarified, "the Pope believes (in them)."

The Italian priest also warned of the existence of bishops and priests who do not believe in Satan in the interview.  "And yet, in the Gospel, Jesus speaks extensively about it, so it should be said, either they've never read the Gospel or they just don't believe it!"

Fr. Jose Antonio Fortea Cucurull, a Spanish priest and theologian who specializes in demonology and is now studying for his doctorate of theology in Rome, responded to Fr. Amorth's assertions on March 1.

After reading reports of Fr. Amorth's accusations pointing a finger at members of the clergy, including cardinals, Fr. Fortea declared that it is a "duty of justice" to speak out in their defense.

Noting that some prelates "are more spiritual and others more earthly, some more virtuous and others more human," he wrote on his blog, "from there to affirm that some cardinals are members of Satanic sects is an unacceptable distance."

The Spanish priest then explained the sources of information used by Fr. Amorth to say that Satanic sects are operating in the Vatican.

In addition to the people that seek help for demonic possession, said Fr. Fortea, "innumerable persons come to us who claim to have visions, revelations and messages from Our Lord." Among these, "a certain number offer apocalyptic messages and revelations about the infiltration of Satanism and the Masons within the dome of the Church."

Fr. Fortea added that the only acceptable stance is to suspend judgment of the messages while they are subjected to time-intensive discernment, "sometimes months for each one of the cases."

The other source Fr. Amorth refers to, according to Fr. Fortea, is the demons who are being exorcised. Of this, the Spanish priest wrote that knowing whether or not the demon is telling the truth "is in many cases impossible."

"We can know with great confidence when a demon tells the truth in the subject directly related with the exorcism. That is, the number of demons, their name and similar things. But we cannot be confident in what regards concrete news relating to people."

"Father Amorth does not have other sources of knowledge than the two that I just cited," indicated the Spanish exorcist, "I refer to his own words for this affirmation."

Fr. Fortea observed that the existence of similar messages from the same sources is "something known by me just as (it has been) by many other colleagues for many years."

"Among exorcists, some have come to similar conclusions as those of Fr. Amorth. Others have not."

Fr. Fortea also defended those implicated in Fr. Amorth's statements, stating, "Our College of Cardinals, if we compare it with past centuries is the most edifying and virtuous that history has ever known. One would have to go back to the epoch of the Roman Empire to find a body of electors so distanced from all earthly pretension as the current one is.

"Cardinals might be better or worse," he reflected, "but all have upright intentions and seek the glory of God."

He concluded by emphasizing, "Statements must be proven, especially when they are about such grave accusations that affect the honorability of those who form part of the Head of the Church as far as they help the Supreme Pastor."

Hombreslobo

The history, meaning, allure and reality of this shapeshifter, the werewolf

MOST OF US are only aware of the werewolf through films, TV shows and perhaps novels, but the tradition of the werewolf reaches back into prehistory, and similar creatures are found in cultures around the world. Why does the werewolf resonate so profoundly with us? We spoke with Dr. Bob Curran, author of Werewolves: A Field Guide to Shapeshifters, Lycanthropes, and Man-Beasts, a brilliant and fascinating look at these creatures and the meaning they have held for humankind through the ages.

Q: How far back have you been able to trace werewolf lore?

Curran: I think that the idea of a werewolf - the man-wolf - can be traced very far back into the mists of pre-history. Our earliest hunter ancestors often competed with the wolf for food, especially when the ground was hard and the game scarce. The wolf, of course, is a perfect hunting and killing machine - it is strong, swift and highly intelligent. Like men, it also lives largely in communities - wolf packs - and has a very strict social order. It may also have been a much more successful hunter than our lumbering hominid ancestors.

Therefore, early man may have feared but also admired the wolf, and may have wished that they were more like it. They may have thought that by donning wolf skins and pelts and by pretending to be wolves, they might acquire some of the creature's skills and abilities. We know this because of a cave drawing found on the wall of an underground chamber in the Montesquieu-Avantes region of the Pyrenees Mountains, which is referred to as "Le Sorcier des Trois Freres" (from the Trois Freres area) and which depicts a curious hybrid creature, half man, half wolf, which appears to be dancing on its hind legs. This is probably a shaman, invoking a wolf spirit for the purposes of hunting, and suggests that early men thought they could call down wolf spirits in order to possess them. The name for such a figure, as coined by the French anthropologist Henri Breuil (1877-1961), is "therianthrope." It's an idealised figure combining both human and animal characteristics, but probably serves as an idea for the first primitive werewolves.

The first written account in Western Europe is to be found in the works of a medieval monk, Geraldus Cambrensis (Gerald of Wales), writing in 1185 in his book A History and Topography of Ireland. In it he records, as fact, an old legend that he may have heard at the courts of his Irish kinsmen, the Fitzgeralds, concerning the Werewolves of Ossory. In this story, a priest, travelling on ecclesiastical business along the borders of Meath in the diocese of Ossory, camps for the night in a forest. There he is approached by a talking wolf, who asks him a religious favour. He and his wife are members of Clan Altan, a clan which was cursed by an irascible holy man, St. Nechtan. Under the terms of the curse, two of the clan members are turned into the shape of wolves for a period of seven years. They then return from the forest and two others take their place. Whilst serving this penance, his wife, in wolf form, has been struck by a huntsman's arrow and is near to death. He asks the priest if he will come and give her the Holy Offices of the Church so that she may die as a Christian. This the priest does, and the wolf guides him to the edge of the forest and directs him where he has to go. The monk promises to return once his business in Meath is complete, but here the story ends and we don't know if he does. To the best of my knowledge, this is the oldest written werewolf tale, but the oral tradition goes back much further than this.

Q: Is the werewolf tradition cross-cultural? Global?

Curran: The idea of changing into another form - that of an animal - is to be found in many cultures and probably dates back to a time when men were little more than animals themselves and serves to emphasise that connection. However, it is not only a wolf that men can transform themselves into, for other animals were also admired. One of these was the bear, and in Scandinavia we find many stories about were-bears. For example, in Norway and Denmark, there are tales of warriors who donned bear-shirts - baar-sark - in order to increase their prowess and ferocity in battle. This is where we get the words "berserk" and "berserker." There were brigades of these warriors, some of whom fought for the Norwegian king Harald Fairhair during the unification of the country in the 9th and 10th centuries.

However, many cultures seem to believe that the transformation occurs into a dog-like creature, although not necessarily a wolf. For instance in the Middle East, the emphasis seems to be on the transformation into creatures like jackals and hyenas. Native American cultures suggest transformation into a coyote or something similar. Japanese culture has a tradition of were-foxes, which are thought to be highly intelligent but great tricksters. So transformation, often into a wolf-like creature, is to be found in a great number of cultures all across the world.

 

Q: Is there a difference between a lycanthrope and a werewolf?

Curran: In popular culture the two terms have often been counted as virtually interchangeable. Some people have, however, seen subtle differences. The term "lycanthropy" is derived from the Greek lykanthropos, meaning "man wolf". Some have argued that the latter is derived from Mount Lykaon in the highlands of Arcadia in the Pelopponnesus peninsula, which was heavily wooded and where wolves were common. There was also said to be a shrine there to the god Zeus in wolf form, where young boys were supposedly taken as part of a "rite of passage" into manhood. It may have been some sort of male bonding session. The name is derived from King Lykaon - a monarch who ruled before the Great Deluge - who, in order to test the divinity of the visiting Zeus, offered him up the flesh of his own son as part of the banquet. The god was so outraged that he turned Lykaon into a wolf.

In some cases, storytellers have used the two terms to differentiate between the transformation of the individual into a pure wolf or into that of a furry man-like creature, such as the wolf-man in a number of films.

Q: Today, werewolves have a sinister or dangerous reputation. Has this always been the case? Are there any exceptions?

Curran: This is an interesting question. In earlier medieval times the werewolf - the man transformed into a wolf - was not a ravening monster, but rather an extremely noble creature. In many of the ancient medieval tales, they are noblemen who have become trapped in the guise of wolves and who behaved like the animals when they were in the forest, but who still retained the sensibilities, intellect and grace of a sophisticated man. In most they had been trapped in their wolf-form by the guile of a woman, and in most stories ultimately redeem themselves and regain their human form - sometimes through the intervention of the king.

One of the most famous medieval tales - Bisclavret - which appears in a collection of prose poems attributed to Marie de France (an unnamed French woman who wrote the lais - or poem-tales - at the court of King Henry II of England in the 12th century) and deals with a noble knight who is transformed into the shape of a wolf by evil magic wrought by his unfaithful wife. He ultimately has his revenge on the woman and her lover, and is restored to human form and even greater honours from the monarch.

It was only in the late medieval period as the Church assumed greater power and control over peoples' lives and perceptions that the idea of the ravening beast - the man who could deliberately change himself into a monster - came into play. The Church portrayed agents of the Devil, living in the midst of God's people and seeking to subvert or kill them. Their only defence against Satan was, of course, the Church itself. In this case, the notion of werewolfery was inextricably linked with that of witchcraft and the witch-hunter's manual, the Malleus Malificarum (The Hammer of the Witch), written by Sprenger and Kramer on the authority of Pope Innocent VIII and printed in 1484, pulled no punches regarding the evil of those who could change their shape and become as wolves. Furthermore, such beings were living in the very heart of communities, and the godly had to be on their guard against them. This moved the werewolf away from the noble beast and into the realms of the savage monster.

Q: Not all shapeshifters are werewolves, but are all werewolves shapeshifters?

Curran: Shapeshifting was a common notion amongst witch-hunters. The Devil could allow his minions to take on whatever form they wanted through dark magic as long as it was for evil purposes. Thus, witches took on the guise of crows, cats, stoats and others; several witches were accused of taking on more than one guise in order to work their evil. The werewolf seems a fairly static transformation. The sorcerer simply took on a form of a wolf and behaved in that fashion. Usually it was to physically attack, kill and eat some of their neighbours. (Cannibalism may have been more common than had been previously supposed during this time.)

The idea of the werewolf may also have referred to actual wolves who behaved oddly and who were then deemed to have some human traits. The term "werewolf" itself, of course, comes from the Saxon wher or war meaning "man" and the word wulf. This term was sometimes used to denote status in Saxon society; in fact, several leading churchmen used the term "wulf" in their names. They were definitely not shapeshifters.

Q: Both vampires and werewolves are very popular right now. We know why vampires are popular - there's a kind of sexy allure. But what do you think accounts for the continued fascination with the werewolf?

Curran: I think that vampire and werewolf stories have survived and still continue to be popular because they address some of our fundamental issues. The vampire, for example, addresses the problems of aging and death. It poses the question - and the hope: "What would it be like to live forever and retain one's looks?" and "If I did live forever, would there be a price?" As you point out, there is a certain sexiness about that idea.

The werewolf idea addresses the notion that, for all our seeming "culture" and "civilisation" there is a remnant of those old prehistoric hunters still buried somewhere in our psyche. I think that idea both fascinates and repels us. I think it is the dichotomy of the civilised man and the wild hunter - or the crouching beast that I think lies within all of us - that proves the basis of that "allure" - a kind of horrified fascination if you will - and has resulted in the notion of the werewolf roaming with us down the years, just as much as the vampire.

Q: In her book The Beast of Bray Road, Linda Godfrey presents some evidence, mostly in the form of eyewitness sightings, that there may actually be real werewolves out there. What do you think? Could there possibly be real werewolves?

Curran: It depends, of course, by what you mean by "real werewolves." Coming from my perspective as a folklorist and a psychologist, the question is not so much "Do these creatures exist?" (a question that I'm asked a lot) - they may or they may not - but a much more interesting question is: "Why do people want - or need - to believe in them? What role does such a belief fulfill in our lives?" As I said above, I think that the werewolf idea addresses a number of very basic questions about ourselves and our nature. Is there perhaps some form of early animalistic-like being lurking beneath the veneer of civilisation? Are we, in effect, really no better than the animals around us? This is, I think, a question which humans have been asking themselves since earliest times, and the werewolf motif is a way of answering it.

There are of course "real" werewolves if you cast your definition wide enough. There have been feral children who have been abandoned by their human parents and who have been raised in the wild by animals, including wolves, which are often sociable animals with a strong emphasis on rearing young. There are children like Amala and Kamala, the "wolf children" found in India in the 1920s. Feral children go back even to Victor, the Wild Boy of Aveyron in 1797 and Peter of Hanover in 1724.

Then, of course, there are those who suffer from mental disorders that make them behave like wolves; there is a specific mental condition known as lycanthropy. But you never know, and I'm not discounting anything. Perhaps out there in the wild woods there is something living which may correspond to our idea of a werewolf - something that might indeed be very hungry.

El nuevo Nintendo DS sera 3D

TOKYO — Nintendo jumped on the 3-D bandwagon Tuesday, saying the next generation of its DS handheld video game console would come with a 3-D display and go on sale within a year.

Unlike the recent flurry of three dimensional films and TV technologies, the new machine, tentatively called the Nintendo 3DS, will not require users to wear special glasses to view images in 3-D, the company said. The new device will be on display at the E3 video game trade show in June, Nintendo said in a press release.

The popularity of 3-D films like "Avatar" from Twentieth Century Fox and "Alice in Wonderland" from Walt Disney Pictures — which required wearing polarized glasses for images to appear in 3-D — has helped propel the popularity of the technology after several false starts in the past.

Now, manufacturers like Samsung, Panasonic and Sony are racing to bring 3-D technology into the living room. The 3-D LCD televisions come with more advanced "active shutter" glasses, which darken and lighten in sync with the TV to help create the illusion of three dimensions. Sony has also said that games for its PlayStation 3 consoles will be available in 3-D.

Samsung of South Korea started selling 3-D-enabled televisions last month, with prices starting at about $1700. The Japanese electronics makers Panasonic and Sony have promised their own versions this year.

Hitachi, another Japanese manufacturer, released a cellphone last year that has a 3-D display that does not require glasses. Hitachi, together with Sharp, supplies LCD screens to Nintendo.

Nintendo would not say what kind of technology its new 3-D handheld employs or how much it would cost. The new console will be compatible with games for Nintendo's older DS and DSi handheld models, the company said.

The Nintendo 3DS will go on sale in the company's next fiscal year, which runs from April 1, 2010, to March 31, 2011.

"We wanted to give the gaming industry a head's up about what to expect from Nintendo at E3," said Ken Toyoda, chief spokesman at Nintendo. "We'll invite people to play with the new device then."

The DS console from Nintendo — the company behind Super Mario and Pokemon games — has been a hit, selling 125 million units since it was introduced in 2004. The DS has outsold a rival handheld game machine from Sony, the PlayStation Portable, by a factor of two to one.

Nintendo has also scored successes, especially among casual game players, with its Wii video game machine. The Wii comes with a wandlike, motion-detecting remote controller that mimics motions in games, like a golf swing or boxing punch. The company has sold 67.5 million units of the Wii since it went on sale in 2006.

But the emergence of unlikely rivals in the mobile game market — the iPhone and iPod Touch, both by Apple — have raised the pressure for Nintendo to launch a new game system.

Apple's multifunction phone and music players run games that can be downloaded from its online iTunes store, and have helped the company build a fan base among less hard-core game players.

Nintendo has struggled to maintain the stellar earnings it has logged in the past few years. Net profit for the nine months through December fell 9 percent to ¥192.6 billion, or $2.1 billion, as strong holiday sales were offset by a stronger Japanese currency, which reduces the value of overseas earnings when converted into yen.

The company, which derives 85 percent of its revenue outside Japan, has been particularly vulnerable to foreign exchange fluctuations. Nintendo continues to forecast a ¥230 billion profit for the full fiscal year through March, on sales of ¥1.5 trillion.

La erupcion del volcan de Islandia, puede tener efectos globales

By Paisley Dodds And Gudjon Helgason, Associated Press
REYKJAVIK, Iceland — Blasts of lava and ash shot out of a volcano in southern Iceland on Monday and small tremors rocked the ground, a surge in activity that raised fears of a larger explosion at the nearby Katla volcano.

Scientists say history has proven that when the Eyjafjallajokull volcano erupts, Katla follows — the only question is how soon. And Katla, located under the massive Myrdalsjokull icecap, threatens disastrous flooding and explosive blasts when it blows.

Saturday's eruption at Eyjafjallajokull (AYA-feeyapla-yurkul) — dormant for nearly 200 years — forced at least 500 people to evacuate. Most have returned to their homes, but authorities were waiting for scientific assessments to determine whether they were safe to stay. Residents of 14 farms nearest to the eruption site were told to stay away.

Several small tremors were felt early Monday, followed by spurts of lava and steam rocketing into the air.

Iceland sits on a large volcanic hot spot in the Atlantic's mid-oceanic ridge. Eruptions, common throughout Iceland's history, are often triggered by seismic activity when the Earth's plates move and when magma from deep underground pushes its way to the surface.

Like earthquakes, predicting the timing of volcanic eruptions is an imprecise science. An eruption at the Katla volcano could be disastrous, however — both for Iceland and other nations.

Iceland's Laki volcano erupted in 1783, freeing gases that turned into smog. The smog floated across the Jet Stream, changing weather patterns. Many died from gas poisoning in the British Isles. Crop production fell in western Europe. Famine spread. Some even linked the eruption, which helped fuel famine, to the French Revolution. Painters in the 18th century illustrated fiery sunsets in their works.

The winter of 1784 was also one of the longest and coldest on record in North America. New England reported a record stretch of below-zero temperatures and New Jersey reported record snow accumulation. The Mississippi River also reportedly froze in New Orleans.

"These are Hollywood-sort of scenarios but possible," said Colin Macpherson, a geologist with the University of Durham. "As the melt rises, it's a little like taking a cork out of a champagne bottle."

There are three main places where volcanoes normally occur — along strike-slip faults such as California's San Andreas fault line, along areas where plates overlap one another such as in the Philippines and the Pacific Rim, and in areas like Iceland, where two of the Earth's plates are moving apart from each other in a so-called spreading system.

Unlike the powerful volcanos along the Pacific Rim where the slow rise of magma gives scientists early seismic warnings that an eruption is imminent, Iceland's volcanos are unique in that many erupt under ice sheets with little warning.

Magnus Tumi Gudmundsson, a geologist at the University of Iceland who flew over the site Monday, said the beginning of Saturday's eruption was so indistinct that it initially went undetected by geological instruments. Many of the tremors were below magnitude 2.6.

Using thermal cameras and radar to map the lava flow, Gudmundsson and other scientists were able to determine that the lava from Eyjafjallajokull was flowing down a gorge and not moving toward the ice caps — reducing any threat of floods.

He said he and other scientists were watching Katla but Monday's trip was meant to assess immediate risk.

"A general expectation is that because of the Eyjafjallajokull eruption, the fissure would widen and in that sense, there's a greater risk of extending into or underneath the glaciers and prompting an eruption at Katla," said Andy Russell with Newcastle University's Earth Surface Processes Research Group, who went with a team to Iceland before the eruption. "From records, we know that every time Eyjafjallajokull erupts, Katla has also erupted."

Russell said past Katla eruptions have caused floods the size of the Amazon and sent boulders as big as houses tumbling down valleys and roads. The last major eruption took place in 1918. Floods followed in as little as an hour.

Those eruptions have posed risks to residents nearby, but most of Iceland's current population of 320,000 live in the capital of Reykjavik on the western part of the island.

Southern Iceland is sparely populated but has both glaciers and unstable volcanoes — a destructive combination.

The last time there was an eruption near the 100-square-mile (160 square-kilometer) Eyjafjallajokull glacier was in 1821, and that was a "lazy" eruption that lasted slowly and continuously for two years.

Iceland is one of the few places in the world where a mid-ocean ridge actually rises above sea level. Many volcanic eruptions along the ocean basin often go undetected because they can't be easily seen.

First settled by Vikings in the 9th century, Iceland is known as the land of fire and ice because of its volcanos and glaciers. During the Middle Ages, Icelanders called the Hekla volcano, the country's most active, the "Gateway to Hell," believing that souls were dragged into the fire below.

The last major volcanic eruption in Iceland occurred in 2004 with the Grimsvotn volcano.

Associated Press writer Paisley Dodds contributed to this report from London.

Los beneficios del agave

Tequila Plant May Help Fight Bone Loss
Artichokes, garlic and onions also contain beneficial fructans, researchers say


TUESDAY, March 23 (HealthDay News) -- An ingredient in agave -- the plant used to make tequila -- may help fight bone-weakening osteoporosis and other diseases, Mexican researchers say.

Agave, artichokes, garlic, onions and chicory are rich, natural sources of fructans -- nondigestible carbohydrates consisting of molecules of fructose linked together into chains, according to background information in a news release from the American Chemical Society.

"Experimental studies suggest that fructans may be beneficial in diabetes, obesity, stimulating the immune system of the body, decreasing levels of disease-causing bacteria in the intestine, relieving constipation and reducing the risk of colon cancer," Mercedes Lopez, of the National Polytechnic Institute in Guanajuato, said in the news release.

Previous research has also suggested that fructans stimulate the growth of beneficial bacteria in the large intestine in a way that increases the body's absorption of minerals, including calcium and magnesium, which are needed for bone growth.

In this study, Lopez and colleagues tested the effects of agave fructans on bone growth in mice. Compared to other mice, those fed agave fructans absorbed more calcium from food, excreted less calcium in their feces, and had a 50 percent increase in levels of a protein associated with the build-up of new bone tissue.

"These results suggest that the supplementation of the standard diet with agave fructans prevented bone loss and improved bone formation, indicating the important role of agave fructans on the maintenance of healthy bone," Lopez said. "They can be used in many products for children and infants to help prevent various diseases, and can even be used in ice cream as a sugar substitute."

But drinking tequila won't help, the study authors noted. The fructans turn into alcohol when agave is processed into tequila, they said.

The study was to be presented Tuesday at the national meeting of the American Chemical Society in San Francisco.

Los ovnis se reúnen en Ciudad de México

Los ovnis se reúnen en Ciudad de México

Redacción

BBC Mundo



El eslogan de la cumbre sobre OVNIS y vida extraterrestre es "2012: Una nueva conciencia".

Una cumbre que pretende atraer a los más destacados especialistas en objetos voladores no identificados (ovnis) y en la vida extraterrestre tiene lugar estos días en Ciudad de México.

Bajo el eslogan "2012: una nueva conciencia", más de 40 oradores muestran las últimas evidencias que, aseguran, han encontrado sobre la actividad extraterrestre.

Esta año, el encuentro, que comenzó el viernes y se extiende hasta este domingo, se centra en la profecía maya de que el mundo llegará a su fin en 2012, explica Julián Miglierini, periodista de la BBC desde Ciudad de México.

clic ¿Cree usted en los ovnis? Participe.
En otro planeta

Miglierini da cuenta de que ésta no es una conferencia ordinaria. Oradores y participantes creen fuertemente que hay vida en otros planetas y que la humanidad, hasta ahora, ha sido ingenua al pensar que está sola en el universo.

No todo se trata de grandes teorías, sino que las historias se tornan muy personales, dice el periodista.

Creo que va ser un día normal. Pero pienso que lo está ocurriendo es ahora mismo: terremotos, tormentas, un invierno increíblemente frío en muchas partes del undo. Sé que mucha gente va a sufrir, pero probablemente pueda ser un nuevo comienzo para la humanidad

Jaime Maussan, ufólogo mexicano

Sixto Paz, de Perú, por ejemplo, cuenta cómo en 1974, luego de varios supuestos avistamientos de ovnis, se encontró con un alienígena en el desierto peruano.

Este alienígena, que según Paz se parecía a un humano, se comunicó telepáticamente y lo "invitó" a viajar a una nueva dimensión, donde se familiarizó con la cultura extraterrestre.

Paz asegura que estos contactos han continuado desde entonces y que por ello ha dedicado su vida a este fenómeno.
2012: el apocalipsis

No es casual que esta cumbre tenga lugar en Ciudad de México. Uno de los grandes puntos de discusión es la profecía atribuida a los mayas, la antigua civilización ubicada en lo que ahora es México, de que el apocalipsis ocurrirá en diciembre de 2012.

Algunos creen que los mayas tuvieron contactos con alienígenas e, incluso, algunos participantes dijeron que los primeros mayas llegaron de otros planetas.


Una profecía maya asegura que el apocalipsis ocurrirá en diciembre de 2012.

El ufólogo mexicano Jaime Maussan opina que "nadie sabe" qué pasará en diciembre de 2012.

"Creo que va ser un día normal. Pero pienso que ahora mismo están ocurriendo muchas cosas: terremotos, tormentas, un invierno increíblemente frío en muchas partes del mundo. Sé que mucha gente va a sufrir, pero probablemente pueda ser un nuevo comienzo para la humanidad", indicó Maussan.

Algunos en la cumbre creen que incluso ha habido actividad de los ovnis exactamente afuera del centro de conferencias.

Paola Harris, una periodista de Estados Unidos especialista en el tema, le dijo a la BBC: "Estuve acá afuera durante la última hora y he visto tres objetos que son absolutamente increíbles".

"Su apariencia era como de esferas y se tornaban alargados, como lápices. Se mantenían arriba de un poste y no se movían", agregó Harris.

Según Miglierini, a pesar del escepticismo general sobre las formas de vidas extraterrestres, en esta cumbre sobre ovnis en México nadie tiene ese tipo de dudas.

Observan OVNIs

New York - 02-03-10 - We live in Spenceport, and on the morning of February 3, 2010, my 15-year-old daughter woke up and looked out the window which her bed is positioned against. She was confused by lights that she saw in the neighbor's back yard.

She thought it was strange to see a plane that low and in that area, so she thought it might be a helicopter... but then she realized there was no helicopter sound. She then realized that it was like a disk or saucer shape, with purple lights going around it.

She noticed 2 round headlights in the front of the craft that she described as looking like bright car head lamps. The "headlights" faded as they got closer to our house.

As the craft slanted upward to go above the trees behind our house, she noticed the bottom of the craft. She explained that the craft was about the distance of 2-3 car lengths from her window, and noticed a light humming sound.

She noticed in detail that the bottom of the craft was oval shaped like the top but longer. Source: www.nuforc.org

Pennsylvania - 02-06-10 - The power went out and bright red and blue lights lit up the sky. Later, green lights flashed.

The power in the neighborhood went on and off from 10:00 PM until 4:00 AM. Since there is almost 2 feet of snow on the ground, it was still bright out. A bright red and blue flash startled me when I was looking out the window (I thought it was police car), but since it is a state of emergency, no cars were allowed on the road.

About 20 minutes later, a bright yellow flash shined in my room. About an hour after that, a bright green flash seemed to light up our whole neighborhood. Right before each of these light anomalies, there was sort of an engine sound, and then the power would cut out.

We have all under the ground power lines as well as no light posts in our neighborhood. When looking out our back window, a yellow light seemed to fly past us on 3 separate occasions. Source: www.nuforc.org

Virginia - 02-14-10- I was outside removing snow in Woodbridge, then I looked up and I'm looking at the Big Dipper, out of nowhere I see 4 or 5 bright, yellow lights moving east. There was no sound at all.

Twenty seconds later another set of yellow lights pop up out of nowhere. They stayed in formation, but then I noticed that two of the lights were moving side to side and behind the others like if they were trying to pass the others.

By this time I am in shock, so I run upstairs to get my wife, and we both go outside and I'm trying to explain to her what I just saw and to please look up at the sky.

A few seconds later we both saw the lights come from nowhere again, and she asked, "What is that?

I asked her if she heard a noise or something. She could not believe what she just saw. It was something that we never have seen before. It was not a helicopter or a plane, we know that much.

What it was we may never know. But I sure would like to know if there is something there. Source: www.nuforc.org

Virginia - 03-10-10 - I first saw a very bright light (as bright as noon day sun), shortly after sundown - about 1850 hours, in the distance over the Blue Ridge west of Staunton, Virginia from my kitchen window. I got my binoculars, 10 power, and went outside.

With the binoculars I saw four very bright lights close together moving slowly to the West - approximate distance 10 miles. As I watched the four lights, three of them appeared to spread out like a fireworks multicolored starburst.

Then, I noticed another object lower on the horizon a few miles to the north, and further away doing the same thing. These were not airplanes or helicopters, I have been around enough of both in the military to know the difference.

The object was moving slowly toward the West probably not more than 10 miles per hour. Altitude estimate about 2,000 feet above the mountain tops for the first object, perhaps lower for the second object.

It was a very clear night with excellent visibility. I lost sight of the object as it moved slowly to the west over the horizon. Source: www.mufon.com

¿Se suicidan los animales?

Forty years ago, Richard O'Barry watched Kathy, a dolphin in the 1960s television show Flipper, kill herself. Or so he says. She looked him in the eye, sank to the bottom of a steel tank and stopped breathing. The moment transformed the dolphin trainer into an animal-rights activist for life, and his role in The Cove, the Oscar-winning documentary about the dolphin-meat business in a small town in Japan, has transformed him into a celebrity.

"The suicide was what turned me around," says O'Barry. "The [animal entertainment] industry doesn't want people to think dolphins are capable of suicide, but these are self-aware creatures with a brain larger than a human brain. If life becomes so unbearable, they just don't take the next breath. It's suicide."
(See the top 10 animal stories of 2009.)

Animal suicide may seem absurd, yet the concept is as old as philosophy. Aristotle told a story about a stallion that leaped into an abyss after realizing it was duped into mating with its mother, and the topic was discussed by early Christian theologians and Victorian academics. "The questioning of animal suicide is essentially people looking at what it means to be human," says Duncan Wilson, a medical historian at the University of Manchester and co-author of a study in the March issue of the British journal Endeavour on the history of self-destructive animals. "The people talking about animal suicide today seem to be using it as a way to evoke sympathy for the plight of mistreated and captive animals."

Changes in how humans have interpreted animal suicide reflect shifting values about animals and our own self-destruction, the paper argues. The Romans saw animal suicide as both natural and noble; an animal they commonly reported as suicidal was one they respected, the horse. Then for centuries, discussion of animal suicide seems to have stopped. Christian thinkers like St. Thomas Aquinas deemed suicide sinful for humans and impossible for animals. "Everything naturally loves itself," wrote Aquinas in the 13th century. "The result being that everything naturally keeps itself in being."

In 19th century Britain, however, after Darwin demonstrated how humans evolved from animals, humane societies formed, vegetarianism and pets became popular, and reports of animal suicide resurfaced. The usual suspect this time was the dog. In 1845 the Illustrated London News reported on a Newfoundland who had repeatedly tried to drown himself: "The animal appeared to get exhausted, and by dint of keeping his head determinedly under water for a few minutes, succeeded at last in obtaining his object, for when taken out this time he was indeed dead."
(See the top 10 animal attacks on humans.)

Wilson's study provides that account of animal suicide and many others — that of a canvasback duck, a cat, pelicans, scorpions — but intentionally doesn't address the issue of whether these animals or any others are technically capable of ending their own lives. Thomas Joiner, a Florida State University psychologist, does take that stand. His new book, Myths About Suicide, links the suicidal tendencies of living creatures. "Across nature there seems to be the same kind of calculation," says Joiner. "Is my death worth more than my life? Suicides of all kinds involve this calculation, from bacteria and insects to conventional suicide deaths and even suicide terrorists."
(Comment on this story.)

The Endeavour paper points to Iberian folklore on suicidal scorpions; when surrounded by flames, they will sting themselves in the back. In the early 1880s in Britain, a debate on the topic blossomed after a London zoologist placed a scorpion in a glass container, administered chloroform and claimed he observed the animal trying to sting itself. To prove him wrong, the psychologist Conwy Lloyd Morgan set up a series of traps for the critters. "He surrounded them with fire, condensed sunbeams on their backs, heated them in a bottle, burned them with phosphoric acid, treated them with electric shocks and subjected them to 'general and exasperating courses of worry,' " notes the Endeavour article.

But concocting cruel experiments to prove far-fetched points, both then and now, has its critics. "I think often our conversations about animals tend to go to these weird extremes and act to conceal what we are doing to them every day," says Jonathan Safran Foer, whose new book, Eating Animals, relates his attempt to understand how animals become food. "Should we swat flies, is it possible that plants like it when we play classical music, can dogs commit suicide — all of these things may be interesting, but they have nothing to do with how we regularly interact with animals."

Foer says he recently watched The Cove and, like others, found the references to animal suicide fishy. "We don't need to make animals like humans in order to treat them with decency," he says. "If we just treated pigs like pigs and cows like cows, that would be sufficient."

British Airways entra en huelga

Tripulaciones de British Airways inician huelga

Redacción

BBC Mundo



La huelga en British Airways comenzó el sábado.

Una huelga de tres días convocada por personal de tripulación de la aerolínea British Airways, se inició el sábado después de que se rompieran las negociaciones entre el sindicato Unite y la empresa británica, una de las mayores compañías aéreas del mundo.

La protesta laboral tiene como objetivo detener planes por parte de la gerencia de British Airways para recortar personal de tripulación.

British Airways esperaba ahorrar US$100 millones anuales con la medida, que busca contener la crisis financiera afrontada actualmente por la aerolínea.

Voceros de la firma aseguran tener planes de contingencia para mantener en el aire a cerca de la mitad de sus aviones pese a la huelga, pero no hay claridad acerca de qué tan exitosa pueda ser la medida.

Largas conversaciones no pudieron evitar la medida de protesta y otro reclamo similar -de cuatro días- ha sido anunciado para el 27 de marzo.
Cancelaciones

El gerente ejecutivo de British Airways, Willie Walsh, tildó la huelga de "profundamente lamentable".

Por su parte, Tony Woodley, secretario general del sindicato que representa al personal de tripulación, declaró que la aerolínea "quiere irse a la guerra" con sus afiliados.

Un total de 1.100 vuelos de British Airways, de los 1.950 programados para operar durante la primera huelga de tres días, serán cancelados.

En Heathrow, el principal aeropuerto de Londres, el 60% de los vuelos de larga distancia estarán en operación.

Sin embargo, los vuelos cortos sólo funcionarán al 30% con la ayuda de aviones alquilados a aerolíneas rivales.

El corresponsal de asuntos económicos de la BBC, Simon Atkinson, advierte que una huelga le cuesta a la empresa decenas de millones de libras esterlinas en gastos adicionales e ingresos perdidos, sin mencionar la pérdida de clientes que dejarán de hacer reservaciones futuras o cancelarán las actuales "por si acaso".

Sin embargo, agrega Atkinson, British Airlines sabe que si resiste la huelga, podría dividir la fuerza laboral de la empresa y recuperar algo de control frente a los sindicatos.

¿El terremoto de Chile movió el eje de la Tierra?

¿El terremoto de Chile movió el eje de la Tierra?

El terremoto de magnitud 8,8 que ocurrió el mes pasado en Chile fue tan fuerte que podría haber movido el eje de la Tierra.



Marzo 11, 2010: Las imágenes de la extensa devastación no dejan lugar a dudas: el terremoto de magnitud 8,8 que tuvo lugar el mes pasado en la costa de Chile fue fuerte. ¿Qué tan fuerte fue? Los científicos de la NASA dicen que podría haber movido el eje de la Tierra.

"Si nuestros cálculos son correctos, el terremoto movió el eje de figura de la Tierra alrededor de 8 cm (3 pulgadas)", dice el geofísico Richard Gross, del Laboratorio de Propulsión a Chorro (Jet Propulsion Laboratory, en idioma inglés), ubicado en Pasadena, California.

Derecha: Un mapa del terremoto de Chile, proporcionado por el USGS. [Más información]

Usted podría pensar que hubiera notado que la Tierra se inclinaba de repente 8 cm (3 pulgadas). Pero no es así como funciona el "eje de figura". "El eje de figura de la Tierra no define cómo está inclinada, sino cómo está equilibrada", dice Gross.

Considere lo siguiente:

La Tierra no es una esfera perfecta. Los continentes y los océanos están distribuidos de manera desigual alrededor del planeta. Hay más tierra en el Norte, y más agua en el Sur, un gran océano en el Oeste y así sucesivamente. Como resultado de estas asimetrías, la Tierra se tambalea lentamente conforme gira. El eje de figura es el eje de equilibrio de masa y el eje de giro se tambalea alrededor de él.

"El terremoto de Chile movió suficiente material como para cambiar el equilibrio de masa del planeta", relata Gross.


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El movimiento del eje de figura no es nada nuevo. Por si sólo, el eje de figura se mueve cerca de 10 centímetros por año como resultado del "rebote de la Era Glacial". Después del último gran período glacial, el cual tuvo lugar hace aproximadamente 11.000 años, muchas capas pesadas de hielo desaparecieron. Esto descargó la corteza y el manto de la Tierra, permitiendo al planeta relajarse o "rebotar" hacia una forma más esférica. El proceso de rebote está aún en camino así que, en consecuencia, el eje de figura se mueve de manera natural.

El 27 de febrero de 2010, el terremoto de Chile podría haber movido, en cuestión de minutos, el eje de figura tanto como se movería normalmente en un año entero. Fue realmente un movimiento sísmico —no fue broma.

Sin embargo, hasta ahora, todo es cálculos y especulaciones. "En verdad, no hemos medido el movimiento", dice Gross. "Pero pretendo intentarlo".

La clave es el GPS1 (Global Positioning System ó Sistema de Posicionamiento Global, en idioma español). "Usando una red global de receptores del GPS, podemos monitorizar la rotación de la Tierra con alta precisión", dice. " Los cambios en la rotación y en la orientación de los ejes de la Tierra afectan [la fase y los tiempos de] las señales que recibimos de los satélites en órbita alrededor de la Tierra".

El GPS ya se utiliza para monitorizar los cambios estacionales en la rotación de la Tierra. Parece ser que las mareas, los vientos, las corrientes oceánicas y los patrones de circulación en el núcleo derretido de la Tierra modulan de manera regular la rotación terrestre. Por ejemplo, un día típico en enero es cerca de 1 milisegundo más largo que un día típico en junio. La variación de más o menos seis meses se produce principalmente debido a los vientos estacionales; también hay cambios en las escalas temporales de semanas, años, décadas y siglos.



Arriba: Cambios observados en la duración del día de la Tierra causados por mareas, vientos, corrientes oceánicas y otros factores. De Treatise on Geophysics (Tratado de Geofísica), 2007, sección 3,09, "Earth Rotation Variation ––Long Period (Variación de la Rotación de la Tierra ––Período Prolongado)", por Richard Gross. [Imagen ampliada]

Los terremotos producen un "pico" en las señales del GPS, el cual Gross cree poder encontrar.

"Tengo que tomar las mediciones de la rotación de la Tierra por GPS y restarle los efectos de las mareas, vientos y corrientes oceánicas", explica. " Entonces el terremoto debe sobresalir".

Los recientes informes en las noticias se han concentrado en la duración del día de la Tierra, y destacan que el terremoto ocurrido en Chile podría haber acortado los días en 1,26 microsegundos de 24 horas. Eso es cierto. Pero también es insignificante comparado con los efectos normales del viento y las mareas, los cuales pueden prolongar o acortar los días mil veces más que los terremotos.

La verdadera noticia, según Gross, es el posible movimiento en el eje de figura de la Tierra. Él tiene una "perspectiva muy a lo JPL" sobre el tema: "Las antenas que usamos para seguir la trayectoria de las naves espaciales en camino a Marte y a otros lugares están ubicadas en la Tierra. Si nuestra plataforma de rastreo se mueve, necesitamos saberlo".

Derecha: El tambaleo normal del eje de la Tierra desde enero de 2009 tal como fue informado por el Servicio Internacional de Rotación de la Tierra (International Earth Rotation Service, en idioma inglés). La rejilla tiene una escala de milisegundos de arco (mas, en idioma inglés); 1 mas = 1/3.600.000 grados. [Imagen ampliada]

Nadie nunca antes ha medido un movimiento del eje de la Tierra debido a un terremoto. En el año 2004, Gross buscó un movimiento producido por el terremoto de magnitud 9,1 ocurrido en Sumatra, pero no encontró una señal. El terremoto de Sumatra fue menos efectivo respecto de alterar el eje de figura de la Tierra debido a su localización cerca del ecuador y la orientación de la falla subyacente. En cambio, el terremoto de Chile, si bien fue más débil, pudo haber producido un movimiento mayor.

El escenario está preparado para un descubrimiento. "El poder de las computadoras nunca había sido tan grande. Nuestros modelos de mareas, vientos y corrientes oceánicas nunca habían sido mejores. Y la orientación de la falla de Chile favorece una señal más fuerte".

En unos pocos meses, Gross espera tener la respuesta. Manténgase actualizado en Ciencia@NASA.

El link: http://ciencia.nasa.gov/headlines/y2010/11mar_figureaxis.htm?list1302451

Una "corriente de fuego" en el Sol adquiere velocidad

Una "corriente de fuego" en el Sol adquiere velocidad

Una "corriente de fuego" masiva en el Sol comenzó a moverse a altas velocidades, sorprendiendo así a investigadores y desafiando algunos modelos existentes del ciclo solar.



Marzo 12, 2010: ¿Qué pretende el Sol ahora?

En la edición del día de hoy de la revista "Science" ("Ciencia", en idioma español), el físico solar David Hathaway, de la NASA, informa que la parte superior del Gran Cinturón Transportador del Sol ha estado girando a velocidades récord en los últimos cinco años.

"Creo que esto podría explicar el inusual profundo mínimo solar que hemos estado observando", comenta Hathaway. "La alta velocidad del cinturón transportador desafía los modelos que existen del ciclo solar y nos ha obligado a volver a la pizarra para buscar nuevas ideas".

El Gran Cinturón Transportador es una corriente de fuego (plasma caliente) de circulación masiva que ocurre dentro del Sol. Posee dos ramificaciones (norte y sur) y a cada una de ellas le toma alrededor de 40 años completar un ciclo. Los investigadores piensan que la inversión del sentido del ciclo controla el ciclo de las manchas solares.

Derecha: Concepto artístico del Gran Cinturón Transportador del Sol. [Imagen ampliada]

Hathaway ha estado monitorizando el cinturón transportador usando datos proporcionados por el Observatorio Solar y Heliosférico (SOHO, en idioma inglés). El flujo superficial del cinturón erosiona la superficie del Sol, barriendo las acumulaciones o nudos de magnetismo solar y transportándolas hacia los polos. El SOHO es capaz de rastrear estos nudos (Hathaway los llama "elementos magnéticos") y, por lo tanto, de revelar la velocidad del flujo que se encuentra por debajo de ellos.


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"Es parecido a medir la velocidad de un río en la Tierra por medio de la observación de las hojas y ramitas que flotan y siguen la corriente en su superficie", explica Hathaway.

El conjunto de datos del SOHO abarca hasta 1996, y cubre un ciclo solar completo. El año pasado, Lisa Rightmire, una estudiante de Hathaway, en la Universidad de Memphis, pasó el verano completo tomando mediciones de los elementos magnéticos. Cuando pudo crear una gráfica de la velocidad de dichos elementos comparada con el tiempo, se dio cuenta de cuán rápido se estaba moviendo el cinturón transportador.

Aclaración sobre el significado de la palabra "rápido": El Gran Cinturón Transportador es una de las estructuras más grandes de todo el sistema solar y, según los estándares humanos, se mueve con una gran lentitud. "Rápido", en este contexto, significa de 10 a 15 metros por segundo (de 20 a 30 millas por hora ó aproximadamente de 32 a 48 kilómetros por hora). Un buen ciclista podría fácilmente mantener esta marcha.

Abajo: Velocidad del Gran Cinturón Transportador (también conocido como "flujo del meridiano") desde 1996. Obsérvense las altas velocidades producidas aproximadamente después del año 2004. Crédito: Hathaway y Rightmire, 2010. [Imagen ampliada]



El aumento de la velocidad ocurrió sorpresivamente en dos niveles.

Primero, coincidió con el mínimo solar más profundo en casi 100 años, contradiciendo así los modelos que predecían que un cinturón rápido debería ocasionar la producción de manchas solares. La idea básica es que el cinturón barre los campos magnéticos de la superficie del Sol y los arrastra hacia abajo, en la dirección en donde se encuentra la dínamo interna del Sol. Allí, estos campos son amplificados para formar las bases de las nuevas manchas solares. Un cinturón transportador que se desplaza rápidamente debería de acelerar este proceso.

De modo que, ¿dónde han estado todas las manchas solares? El mínimo solar de 2008-2009 fue inusualmente profundo y ahora el Sol parece estar en los comienzos de un nuevo ciclo solar débil.

En lugar de producir manchas solares, Hathaway cree que un cinturón transportador rápido puede suprimirlas "si contrarresta la difusión magnética en el ecuador del Sol". Él describe el proceso en detalle en la revista "Science" ("Variaciones en el flujo meridional del Sol a través de un ciclo solar" ó "Variations in the Sun's Meridional Flow over a Solar Cycle", 12 de marzo de 2010, v327, 1350-1352).

La segunda sorpresa tiene que ver con el fondo del cinturón transportador.

El SOHO solamente puede cronometrar los movimientos de la cubierta visible del flujo. El fondo está escondido por ~200.000 kilómetros de cubierta de plasma. Sin embargo, se puede lograr una estimación de su velocidad por medio del rastreo de las manchas solares.

"Las manchas solares están supuestamente enraizadas al fondo del cinturón", comenta Hathaway. "De modo que el movimiento de las manchas solares nos indica cuán rápido se está moviendo el cinturón allá abajo".

Él hizo justamente eso (confeccionó una gráfica que compara la velocidad con el momento en el que se produjeron las manchas solares desde 1996) y los resultados no tienen sentido. "Mientras que la parte superior del cinturón transportador se ha estado moviendo a velocidades muy elevadas, que marcan un récord, el fondo parece estar moviéndose a velocidades muy bajas, las cuales también establecen un récord. Otra contradicción".

Derecha: Concepto artístico del Observatorio de Dinámica Solar (SDO, en idioma inglés). Lanzado en febrero de 2010, el SDO será capaz de observar el interior del Sol para estudiar el cinturón transportador en mayor detalle, tal vez resolviendo de ese modo los misterios que develaron Hathaway y Rightmire. [Imagen ampliada]

¿Podrá suceder que las manchas solares no se encuentren enraizadas al fondo del cinturón transportador, después de todo? "Esa es una posibilidad", agrega el científico. "Las manchas solares podrían encontrarse en movimiento debido a las ondas generadas por la dinámica interna del Sol o por algún otro fenómeno que no se encuentre vinculado con el cinturón transportador".

Los investigadores realmente necesitan una buena y profunda "mirada" al interior del Sol. El Observatorio de Dinámica Solar, de la NASA, lanzado en febrero de 2010, lo hará posible cuando sus instrumentos se enciendan más adelante este mismo año. El SDO podrá confeccionar mapas del interior del Sol usando una técnica llamada heliosismología. El SOHO puede hacer lo mismo, pero no lo suficientemente bien como para analizar el Gran Cinturón Transportador durante todo su ciclo. Los sensores avanzados del SDO podrían revelar el ciclo completo.

¿Y luego? "Podría ser la pieza ausente que necesitamos para predecir todo el ciclo solar", comenta Hathaway.

Manténgase sintonizado para encontrarla.

El link: http://ciencia.nasa.gov/headlines/y2010/12mar_conveyorbelt.htm?list1302451

Equinoccio: espectáculo celeste

Equinoccio: espectáculo celeste

Tome sus binoculares. La Luna creciente y el cúmulo estelar de las Pléyades se están aproximando para tener un encuentro cercano la primera noche de la primavera (boreal). Es la mejor conjunción entre la Luna y las Pléyades que se verá en Estados Unidos hasta el año 2023.



Marzo 19, 2010: Cuando se ponga el Sol el sábado 20 de marzo, una noche especial cubrirá la Tierra. Es una noche que dura igual que el día.

O, como diría un astrónomo, "es un equinoccio". Es la fecha en la cual el Sol cruza el ecuador celeste en su camino hacia el norte. La primavera comienza en un hemisferio, y el otoño, en el otro. El día y la noche duran casi lo mismo.

Para celebrar la ocasión, la naturaleza brinda un espectáculo celeste.

Todo comienza cuando el cielo oscurece. Primero se materializa la Luna, una robusta media luna en el cielo, ubicada a un tercio de camino desde el horizonte en el cielo del oeste. Espere hasta que el crepúsculo azul se vuelva completamente negro y se dará cuenta de que la Luna no está sola. Las Pléyades también están allí.

La Luna y las Pléyades tendrán un encuentro cercano de rara belleza. Hay tan poco espacio entre las dos, que el borde de la Luna verdaderamente cubrirá algunas de las estrellas menos brillantes del cúmulo. Según David Dunham, de la Asociación Internacional para el Cronometraje de Ocultaciones (International Occultation Timing Association, en idioma inglés), esta es la mejor conjunción entre la Luna y las Pléyades que se verá en Estados Unidos hasta el año 2023.

Derecha: Una conjunción similar entre la Luna y las Pléyades fotografiada por Marek Nikodem, de Szubin, Polonia, en julio de 2009.

Las Pléyades son un cúmulo de estrellas jóvenes ubicadas a aproximadamente 440 años luz de la Tierra. Se formaron a partir de una nube de gas interestelar que colapsaba hace alrededor de 100 millones de años. Para los estándares de la astronomía eso es realmente joven. La Tierra que está debajo de nuestros pies es casi 50 veces más vieja. Los dinosaurios vagaban por nuestro planeta mucho antes de que las Pléyades llegaran a existir.


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Solamente siete de las Pléyades se pueden observar a simple vista. Las "Siete Hermanas" son: Estérope, Mérope, Electra, Maya, Táigete, Celeno y Alcíone, nombradas en honor a las hijas del dios Atlas de la mitología griega. Juntas forman la figura de una pequeña cacerola, por lo cual las Pléyades son con frecuencia confundidas con la Pequeña Cacerola, un asterismo de la Osa Menor.

Se recomienda utilizar binoculares para apreciar este evento.

Primero escudriñe la Luna. Verá cráteres, montañas y mares de lava. Note que usted puede ver la Luna completa, no solamente la brillante media luna iluminada. El terreno oscuro de la Luna está iluminado por un brillo fantasmal llamado "brillo de la Tierra". Es la luz de nuestro propio planeta azul que ilumina a la Luna.

Después, examine el cielo alrededor de la Luna. Las Pléyades se verán con nitidez —y son más de siete. Incluso a través de la óptica más modesta, es posible ver docenas de "hermanas" menos brillantes.

Esta noche no será igual. Será mucho mejor.

¡Experimente el equinoccio!

El link: http://ciencia.nasa.gov/headlines/y2010/19mar_equinox.htm?list1302451

Colisionador de Hadrones rompió récord

Colisionador de Hadrones rompió récord

Redacción

BBC Mundo


El Gran Colisionador de Hadrones (LHC, por sus siglas en inglés), el experimento físico más grande del mundo, ha roto su propio récord de colisión de partículas de energía.


El mayor acelerador de partículas del mundo triplicó la energía más intensa jamás alcanzada en sus preparativos para escudriñar los secretos del universo.


La Organización Europea para la Investigación Nuclear (CERN por sus siglas en inglés), dijo que un haz de protones circuló este viernes por la mañana a 3,5 billones de teraelectronvoltios (TeV) en ambas direcciones en el túnel de 27 kilómetros del LHC, construido bajo la frontera franco-suiza, en Ginebra.

Conocido como "La máquina de Dios", el mayor acelerador de partículas del mundo triplicó la energía más intensa jamás alcanzada en sus preparativos para escudriñar los secretos del universo.

El acelerador superó su récord de diciembre, cuando alcanzó los 2,36 TeV, el nivel de energía más alto logrado por cualquier acelerador en el mundo.

El LHC tiene ahora un nuevo objetivo: hacer colisionar dos haces de protones para crear nuevas partículas, que serán examinadas a fin de obtener más información sobre la composición de la materia.

Los científicos esperan, además, analizar en escala infinitesimal lo que sucedió en las primeras fracciones de segundo después de la Gran Explosión, conocida como Bing Bang, que según la teoría vigente dio comienzo al universo hace casi 13.000 millones de años.

CERN reportó varios éxitos experimentales desde que reanudó el acelerador el año pasado, luego de 14 meses de reparaciones y mejoras y una falla cuando los científicos intentaron poner en marcha el aparato.

CERN mejoró el aparato durante una reciente desactivación de dos meses y medio para poder usarlo con mayor energía experimental.

"Lograr que el haz de partículas circule a 3,5 billones TeV es una prueba de la solidez del diseño general del acelerador, y las mejoras que realizamos desde septiembre de 2008", dijo el director del CERN para aceleradores y tecnología, Steve Myers.
Demora de dos años

Recientemente, los encargados del LHC decidieron detener su marcha por un año, debido a cuestiones de seguridad y para que los científicos puedan corregir errores de diseño.


CERN mejoró el aparato durante una reciente desactivación de dos meses y medio.


En declaraciones a la BBC, el doctor Myers dijo que, como consecuencia, el LHC demorará dos años en alcanzar su potencial máximo.

Además, es necesario que se resuelvan los errores de construcción detectados en el túnel.

"Es algo que con muchos más recursos y con más personal y controles de calidad posiblemente hubiésemos podido evitar", explicó Myers.

El cierre previsto para finales de año es uno más en la cadena de retrasos que han afectado a la máquina operada por el CERN e inaugurada en septiembre de 2008 en medio de grandes expectativas.

Los ingenieros estiman que el acelerador es seguro para manejar la energía prevista para los próximos meses, pero quieren evitar a toda costa otra avería, explica Judith Burns, de BBC Ciencia.

Con ese objetivo, han tomado la decisión de operar el aparato a la mitad de su capacidad máxima antes de apagarlo a finales de 2011 para emprender las correcciones.

El link: http://www.bbc.co.uk/mundo/ciencia_tecnologia/2010/03/100319_1955_colisionador_hadrones_record_gm.shtml

Descubren exoplaneta

Astrónomos descubren un planeta "similar" a los del sistema solar
Miércoles, 17 de marzo de 2010 a las 18:38

El planeta descubierto tiene una masa parecida a la de Júpiter (EFE).
Lo más importante
El descubrimiento de este cuerpo permitirá conocer mejor a otros exoplanetas, afirman científicos

CIUDAD DE MÉXICO (CNNMéxico) — Astrónomos descubrieron un planeta del tamaño de Júpiter que orbita alrededor de una estrella semejante al Sol y que es "similar" a los de nuestro sistema solar, informó este miércoles el Instituto de Astrofísica de Canarias (IAC) en España.

El exoplaneta, bautizado CoRoT-9b por haber sido detectado por el telescopio espacial CoRoT, se ubica en la constelación de la Serpiente a 1,500 años luz de la Tierra, de acuerdo con el hallazgo publicado en la más reciente edición de la revista científica Nature.

Según el IAC, la distancia entre el exoplaneta gigante y gaseoso y la estrella alrededor de la cual orbita es semejante a la que existe entre Mercurio y el Sol. Sus rasgos, agregó, son comunes a las de otros descubiertos hasta ahora y representan un valioso modelo para identificar nuevos cuerpos con temperaturas moderadas.

El telescopio espacial CoRoT (Convección, Rotación y Tránsitos) fue construido por la agencia francesa CNES con ayuda de Austria, Alemania, Bélgica, Brasil, España y la Agencia Europea Espacial (ESA), específicamente para la detectar exoplanetas en tránsito y estudios sismológicos de estrellas.

La investigación fue dirigida por el astrónomo del IAC Hans Deeg, quien dijo que es el primer exoplaneta sin temperaturas muy altas cercano a su estrella, y al que se pueden aplicar los modelos del sistema solar de la Tierra.

Una de las implicaciones de este descubrimiento es que nuestro sistema solar no es un caso muy especial y que los sistemas de planetas extrasolares no son muy diferentes al nuestro. Gracias al análisis de tránsitos, la información sobre CoRoT-9b es mayor que la disponible sobre otros planetas similares.

Hasta ahora se han descubierto más de 400 exoplanetas, de los que alrededor de 70 han sido hallados por el método de tránsito. Los tránsitos tienen lugar cuando un cuerpo celeste bloquea algo de luz al pasar frente a su estrella anfitrión y esta especie de eclipse causa variaciones en el brillo de la estrella que permiten deducir la masa, diámetro, densidad y temperatura del planeta.

El hecho de que CoRoT-9b tarde 95 días terrestres en girar alrededor de su estrella demuestra la utilidad de este método para encontrar planetas con largos periodos orbitales.

El satélite espacial CoRoT identificó el planeta tras 150 días de observaciones durante el verano de 2008 y sus parámetros se verificaron durante 2009 desde el telescopio IAC-80 del Observatorio del Teide, en Tenerife, España.

El instrumento HARPS del Observatorio Austral Europeo (ESO) y otros telescopios terrestres permitieron medir su masa y corroborar su naturaleza como planeta extrasolar.

El astrofísico de la Universidad de Niza Tristán Guillot indicó que, según los modelos, el interior sólido de este planeta tendría una masa de hasta 20 masas terrestres, muy similar al de Júpiter. La temperatura en su superficie gaseosa está entre 150 grados centígrados y unos 20 bajo cero, con mínimas variaciones entre el día y la noche.

Los OVNIs y Pie Grande son lo mismo

That headline is enough to frighten even the most seasoned UFO researcher or cryptozoologist, but a brave (and wonderfully titled) post over at the Blogsquatcher looks at electromagnetic effects associated with Bigfoot sightings. Be sure to read all of the detailed history of this phenomenon.

Turns out that there are documented instances of dying car engines associated with Bigfoot sightings. Some of us may have heard of the tendency for some UFOs to stop cars (and sometimes restart them) as well. Doesn't it seem a bit odd that two things that are considered so dissimilar could have the same effects associated with them?

The introduction of this sort of speculation may cause many to jump to the conclusion that I am saying that Bigfoot and UFOs are the same thing. Not so. They may impinge on some of the same areas and have the same effects associated with them, which is a good indication that at least some aspects of these paranormal subjects may have similar origins, at least as we perceive them. The physical effects may be a epiphenomenon of the forces at work when something strange is experienced, or perhaps it is the other way around. Or both.

The Blogsquatcher asks why there are still no pictures of Bigfoot from numerous automatic cameras set up to capture an image when they detect movement. Perhaps the simple answer is that the creature actually requires a witness to "call it into existence." This is also something that has been argued for some UFO cases. Of course, this brings to mind the so-called "tulpa" theory. You may know that Nick and I are fans of this sort of speculation, not as an explanation for the whole UFO subject, but as an adjunct.

As for Bigfoot and UFOs in the same vicinity, there are a few examples in existence, such as this one, and shenanigans around Dulce, New Mexico (as if that area didn't have enough strangeness already.)

Observan OVNIs

California - 02-04-10 - My dad and I were in the car, on Park Dr. and Sunset Blvd., heading to Chick-Fil-A to grab some dinner. Then, my dad said, "Look, right there!" and he pointed to a little white dot in the sky, and it was bright.

It kind of looked like the north star, but brighter and bigger. Then, after about a second passed, It got REALLY big and REALLY bright, and then a really bright glow formed around it, and then it disappeared.

It was big, white, and bright. We looked around in the sky, but we couldn't see it. He said that something told him to look that direction, then he saw it and pointed it out to me. He thought that it was a helicopter with a searchlight or something, but it disappeared. The object didn't move, it just stayed there and got brighter and bigger. Source: www.mufon.com

California - 02-03-10 - Arriving home from a trip to Santa Maria, my brother and I were admiring the stars in an unusually clear sky. The location of his home, being well away from the city, made for very little or no light pollution so we could even see the billowy dust lane of the Milky Way.

My brother told me to look just to the right and above the constellation Orion, because he had seen a flash there. Sure enough, the next time it flashed I saw it as well.

A few seconds later there was a third flash. These flashes were no brighter than the stars in Orion, with the intensity seeming to vary somewhat each time. The color seemed to vary each time as well. I detected amber, green, blue, and a grayish white at various times during this sighting.

My brother began counting between flashes, "one-thousand one, two-thousand, three-thousand..." We found that the flashes were almost exactly ten seconds apart. After many flashes I detected that the position of the flash was now changing slightly with each flash.

Over the course of one-half hour, the flash moved from a position directly in line with the three stars in Orion's sword, above, and to the right of Orion's belt, to a position still above, but to the left of Orion.

By this time, the brightness of the flashes was quite dim, although they were definitely still detectable. We then carried our stuff into the house, coming out about a half-hour later to check on the anomaly, but the flashing was no longer going on. Source: www.mufon.com

Illinois - 01-27-10 - My husband and I had just pulled into McDonald's parking lot and stopped the car. I looked up and directly in front of us was a Petsmart. Right over the top of Petsmart I saw three REALLY bright white lights.

They were very low and seemed to be sitting still at first. I thought maybe it was just a very low airplane coming straight, and that's why it seemed to be moving slowly.

Then I could tell it was getting closer, and I even made the comment to my husband, "If that's an airplane it's awfully low." I had looked at the clock and it said exactly 8:45. My husband I both sat and watched it and it was taking forever for it to get to us, considering it was so close to begin with...

I looked back at the clock and it was 8:48 and was just getting to be almost directly over our car. My husband got out and went on inside the store (he said he thought it was strange, but he's not really interested in this kind of thing), and I sat in the car and still watched it.

I rolled down the windows of the car and there was NO sound at all... even though it almost directly above the car and I could tell at this point that it was a black triangle-shaped object. It was just HOVERING... not making a sound, no engine noise or anything.

It was really eerie to watch it just gliding along completely silent. It was still moving really slowly and as it banked (sort of like the jets do in the air shows) and got further away, I looked at the clock again and it was 8:51. I watched it until it got far enough away that it was hard to see. It was 8:58 whenever I stopped watching.

I had my cell phone with me and WANTED to take a picture of it, but for one, I've never taken a picture with my cell phone and didn't want to try at that moment to figure it out. Also, I was in total awe of this thing. It was SO pretty and SO huge.

I really didn't want to stop watching it, and except for glancing at the clock a few times, I just wanted to keep watching... when it 'banked' to turn it was incredible. It was just gliding along completely silent... my husband estimated it to be no more than 300 feet in the air. Source: www.mufon.com

Oklahoma - 01-22-10 - This report is being submitted by Oklahoma State Director, Marilyn Carlson for the witness. He contacted director by phone.

Witness saw a bright light in the night sky while he was outside taking a smoke break. At first he thought it might be an airplane, but it was silent and glided along the sky and had no other flashing lights or colored lights.

It was very bright, white star-like appearing. He could not tell the shape due to the brilliance of the light. He watched for about 15 minutes and it slowly disappeared.

A military jet flew overhead almost immediately after the light disappeared. The wife also saw the object. Source: www.mufon.com

El Telescopio Espacial Hubble observa una posible colisión de asteroides

El Telescopio Espacial Hubble observa una posible colisión de asteroides

Los astrónomos han usado el telescopio espacial para mirar de cerca los desechos polvorientos de lo que podría ser la primera colisión frontal de dos asteroides jamás observada.



Febrero 2, 2010: El Telescopio Espacial Hubble, de la NASA, ha observado un misterioso patrón de desechos de polvo con forma de 'X' y serpentinas de polvo rezagado, lo que sugiere una colisión frontal entre dos asteroides. Durante mucho tiempo, los astrónomos han creído que el cinturón de asteroides se pulveriza a medida que se producen las colisiones, pero un choque violento como éste nunca antes había sido observado.

El objeto, llamado P/2010 A2, fue descubierto por el Programa Lincoln de Investigación y Seguimiento de Asteroides Cercanos a la Tierra (Lincoln Near-Earth Asteroid Research o LINEAR, en idioma inglés), el pasado 6 de enero. Al principio, los astrónomos pensaron que podría haber sido uno de los llamados "cometas del cinturón principal" (un raro tipo de cometa que tiene su órbita dentro del cinturón de asteroides). Sin embargo, las imágenes de seguimiento que se tomaron con el Telescopio Espacial Hubble, el 25 y 29 de enero, revelaron un complejo patrón de estructuras filamentosas en forma de 'X' cerca del núcleo:



"Esto es muy diferente del polvo fino que recubre a los cometas normales", dice David Jewitt, de la Universidad de California, en Los Ángeles, quien es el investigador principal del fenómeno. "Los filamentos están hechos de polvo y grava, y se presume que fueron expulsados del núcleo recientemente. Parte de este material ha sido barrido por la presión de la radiación de la luz solar, creando de este modo trazas rectas de polvo. Incrustadas en los filamentos, hay condensaciones de polvo que se mueven de manera conjunta y que se formaron probablemente a partir de pequeños cuerpos rocosos originarios que no habían sido observados con anterioridad".


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El telescopio Hubble muestra que el núcleo principal de P/2010 A2 yace fuera de su propio halo de polvo. Esto nunca había sido visto antes en un objeto similar a un cometa. Se estima que el núcleo mide 140 m (460 pies) de diámetro.

Los cometas normales caen a las regiones interiores del sistema solar provenientes de reservorios de hielo en el lejano cinturón de Kuiper y la nube de Oort. Conforme los cometas se aproximan al Sol y se calientan, el hielo que se encuentra cerca de la superficie se evapora y expulsa material del núcleo sólido del cometa, en forma de chorros. Pero el P/2010 A2 podría tener un origen distinto. Su órbita está en la región interna, más caliente, del cinturón de asteroides, donde sus vecinos más cercanos son cuerpos rocosos secos que carecen de materiales volátiles.

Esto deja abierta la posibilidad de que la compleja traza de desechos sea el resultado de un impacto entre dos cuerpos, en vez de hielo que simplemente se derrite y sale despedido de un cuerpo originario.

"Si esta interpretación es correcta, dos asteroides pequeños y desconocidos con anterioridad colisionaron recientemente, creando de este modo una lluvia de desechos que está siendo barrida hacia atrás (formando una cola a partir del sitio de la colisión) por la presión de la luz solar", dice Jewitt.

Las colisiones entre asteroides son energéticas, con una velocidad promedio de impacto de más de 17.700 km/h (11.000 mph); esto es cinco veces más rápido que la bala de un rifle. El núcleo principal de P/2010 A2 sería el remanente de esta llamada colisión de hipervelocidad.

Derecha: Imagen en tamaño completo de P/2010 A2. Crédito: NASA, ESA, y D. Jewitt (Universidad de California, Los Ángeles). Fotografía No. STScI-2010-07 [Imagen ampliada]

"La apariencia filamentosa de P/2010 A2 es distinta de cualquier cosa que haya sido observada antes por el telescopio Hubble en cometas normales, lo cual es coherente con el hecho de que hayan actuado diferentes procesos", dice Jewitt. Un origen provocado por un impacto también sería coherente con la ausencia de gas en espectros obtenidos con telescopios ubicados en la Tierra.

El cinturón de asteroides contiene evidencias abundantes de colisiones antiguas que han despedazado cuerpos precursores hasta convertirlos en fragmentos. La órbita de P/2010 A2 está vinculada con el hecho de que sea miembro de la familia de asteroides llamada Flora, producida por despedazamiento provocado por una colisión hace más de 100 millones de años. Un fragmento de aquel rompimiento pudo haber caído sobre la Tierra hace 65 millones de años, desatando así una extinción en masa que acabó con los dinosaurios. Pero, hasta ahora, no se había captado "en el acto" una colisión de asteroide contra asteroide.

En el momento de las observaciones que se llevaron a cabo con el telescopio Hubble, el objeto se encontraba a aproximadamente 290 millones de kilómetros (180 millones de millas) de distancia del Sol y a 145 millones de kilómetros (90 millones de millas) de la Tierra. Las imágenes proporcionadas por el telescopio Hubble fueron tomadas con la nueva Cámara de Campo Amplio 3 (Wide Field Camera 3 o WFC3, en idioma inglés).

Fuente: http://ciencia.nasa.gov/headlines/y2010/02feb_asteroidcollision.htm?list1302451

La misión Firefly estudiará los destellos de rayos gamma terrestres

La misión Firefly estudiará los destellos de rayos gamma terrestres

Hay un misterio en los cielos de la Tierra: algo está produciendo haces luminosos de radiación gamma en la parte superior de la atmósfera de nuestro propio planeta. Una nueva misión de NASA-NSF, llamada Firefly (Luciérnaga), lo va a investigar.



Enero 29, 2010: Las explosiones de rayos gamma de alta energía generalmente ocurren en la lejanía del espacio exterior, tal vez cerca de los agujeros negros o de otros fenómenos cósmicos de alta energía. Así que imagine la sorpresa de los científicos, a mediados de la década de 1990, cuando encontraron estos poderosos destellos de rayos gamma que provenían de nuestra propia Tierra, del cielo justo arriba de nosotros.

Se los llama Destellos de Rayos Gamma Terrestres o DRGT, por su sigla en idioma español (TGF, por su sigla en idioma inglés), y se conoce muy poco sobre ellos. Al parecer, tienen cierta conexión con los relámpagos, pero los Destellos de Rayos Gamma Terrestres en sí son algo totalmente diferente.

Derecha: Concepto artístico de los DRGT. Crédito: NASA/Robert Kilgore [Más información]

"De hecho", dice Doug Rowland, del Centro Goddard para Vuelos Espaciales, de la NASA, "antes de los '90 nadie sabía siquiera que existían. Y, sin embargo, son los aceleradores de partículas más potentes que hay en la Tierra".

Las partículas individuales de los DRGT adquieren una enorme cantidad de energía, algunas veces el exceso llega a ser de hasta 20 mega electronvoltios (MeV). En contraste, las coloridas auroras boreales que iluminan los cielos de las altas latitudes son producidas por partículas con una energía menor que una milésima de dicha energía.


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En este momento, hay más preguntas sobre los DRGT que respuestas. ¿Qué es lo que causa estos destellos de alta energía? ¿Acaso los DRGT ayudan a provocar los relámpagos, o son los relámpagos los que provocan los DRGT? ¿Podrían ser éstos responsables de algunas de las partículas de alta energía en los cinturones de radiación de Van Allen, las cuales pueden causar daños a los satélites?

Para investigar esto, Rowland y sus colegas en el GSFC, en la Universidad Siena, en la Asociación de Universidades de Investigación Espacial y en el Instituto Hawk de Ciencias del Espacio están planeando enviar, en 2010 o 2011, un pequeño satélite, del tamaño de un balón de fútbol, llamado Firefly (Luciérnaga, en idioma español). Debido a su pequeño tamaño, Firefly costará menos de 1 millón de dólares (cerca de 100 veces más barato de lo que cuestan normalmente las misiones de satélites). Parte del ahorro en su costo se debe a que Firefly será lanzado de acuerdo con lo dispuesto por el programa CubeSat, de la Fundación Nacional de Ciencia (National Science Foundation, en idioma inglés), en virtud del cual se envían pequeños satélites como "polizones" a bordo de cohetes que transportan satélites más grandes hacia el espacio, en lugar de llevar a cabo lanzamientos de cohetes especialmente realizados para ellos.

Abajo: Concepto artístico de Firefly en su búsqueda de DRGTs por encima de una tormenta. Firefly realizará mediciones simultáneas de electrones energéticos, de rayos gamma y de las huellas en óptico y de radio de las descargas eléctricas. [Más información]



Si llega a tener éxito, Firefly enviará de regreso las primeras mediciones simultáneas de DRGTs y relámpagos. La mayoría de lo que se sabe sobre los DRGT hasta la fecha ha sido a través de misiones dedicadas a observar rayos gamma que provienen del espacio profundo, tales como el Observatorio Compton de Rayos Gamma, de la NASA, el cual descubrió los DRGT en 1994. Mientras contemplaba el espacio exterior, Compton alcanzó a vislumbrar rayos gamma con el rabo del ojo, por así decirlo. Los poderosos destellos venían (¡sorpresa!) de la atmósfera de la Tierra.

Datos posteriores proporcionados por Compton y otros telescopios espaciales han ofrecido un esquema tentadoramente incompleto de cómo ocurren los DRGT:

En el cielo, por encima de alguna tormenta eléctrica, los poderosos campos eléctricos generados por dicha tormenta se extienden hacia arriba por varios kilómetros en la atmósfera superior. Estos campos eléctricos aceleran a los electrones libres, llevándolos a velocidades muy cercanas a la de la luz. Cuando estos electrones ultra rápidos colisionan con las moléculas del aire, se liberan rayos gamma de alta energía y también más electrones, formándose de este modo una cascada de colisiones y tal vez más DRGTs.

Derecha: Doug Rowland, el principal investigador de Firefly, posa junto a un modelo en tamaño real del pequeño satélite. Crédito: NASA/Pat Izzo.

A simple vista, un DRGT probablemente no parecería ser mucho. A diferencia de los relámpagos, la mayor parte de la energía de los DRGT se libera en forma de rayos gamma invisibles, no en forma de luz visible. Estos no producen explosiones coloridas o luces como otros fenómenos relacionados con los relámpagos. Sin embargo, estas erupciones invisibles podrían explicar por qué ocurren los brillantes rayos.

Un viejo misterio sobre los relámpagos es cómo se inicia un rayo de tormenta. Los científicos saben que la turbulencia dentro de las nubes separa las cargas eléctricas, generando de este modo enormes voltajes. Pero el voltaje necesario para ionizar al aire y generar una chispa es aproximadamente 10 veces mayor que el voltaje que generalmente se encuentra dentro de las nubes de las tormentas.

"Sabemos cómo se cargan las nubes", afirma Rowland, "lo que no sabemos es cómo se descargan. Y ese es el misterio".

Los DRGT podrían proporcionar dicha chispa. Al generar un repentino flujo de electrones, los DRGT podrían ayudar a que se generen los rayos, sugiere Rowland. "Tal vez este fenómeno es la razón por la que tenemos relámpagos", comenta.

Si esto es así, debería haber más DRGTs por día de los que actualmente conocemos. Las observaciones llevadas a cabo por Compton y otros telescopios espaciales indican que podría haber menos de 100 DRGTs en el mundo cada día. Los rayos se producen millones de veces al día en el mundo. La diferencia es grande.

Pero, una vez más, Compton y los otros telescopios espaciales anteriores a Firefly en verdad no estaban buscando directamente los DRGT. Así que tal vez no es soprendente que no hayan encontrado muchos. Firefly buscará específicamente destellos de rayos gamma que provienen de nuestra atmósfera, no del espacio, llevando a cabo así la primera búsqueda enfocada a la actividad de los DRGT. Los sensores de Firefly serán capaces incluso de detectar los destellos que son generalmente oscurecidos por el aire intermedio, el cual absorbe de manera eficiente los rayos gamma (lo que protege a la gente sobre la superficie de la Tierra de la energía de estos destellos). La búsqueda que realizará Firefly proporcionará a los científicos una mejor estimación de la cantidad de DRGTs en todo el mundo y ayudará a determinar si su relación con los relámpagos es real.

Permanezca sintonizado con Ciencia@NASA para conocer las actualizaciones sobre el tema.

Link: http://ciencia.nasa.gov/headlines/y2010/29jan_firefly.htm?list1302451