NASA scientists who monitor the Sun say that our star's awesome magnetic field is flipping -- a sure sign that solar maximum is here.

The Sun's magnetic north pole, which was in the northern hemisphere just a few months ago, now points south. It's a topsy-turvy situation, but not an unexpected one.

"This always happens around the time of solar maximum," says David Hathaway, a solar physicist at the Marshall Space Flight Center. "The magnetic poles exchange places at the peak of the sunspot cycle. In fact, it's a good indication that Solar Max is really here."

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Above: Sunspot counts, plotted here against an x-ray image of the Sun, are nearing their maximum for the current solar cycle.

The Sun's magnetic poles will remain as they are now, with the north magnetic pole pointing through the Sun's southern hemisphere, until the year 2012 when they will reverse again. This transition happens, as far as we know, at the peak of every 11-year sunspot cycle -- like clockwork.

Earth’s magnetic field also flips, but with less regularity. Consecutive reversals are spaced 5 thousand years to 50 million years apart. The last reversal happened 740,000 years ago. Some researchers think our planet is overdue for another one, but nobody knows exactly when the next reversal might occur.

Although solar and terrestrial magnetic fields behave differently, they do have something in common: their shape. During solar minimum the Sun's field, like Earth's, resembles that of an iron bar magnet, with great closed loops near the equator and open field lines near the poles. Scientists call such a field a "dipole." The Sun's dipolar field is about as strong as a refrigerator magnet, or 50 gauss (a unit of magnetic intensity). Earth's magnetic field is 100 times weaker.

Below: The Sun's basic magnetic field, like Earth's, resembles that of a bar magnet.

When solar maximum arrives and sunspots pepper the face of the Sun, our star's magnetic field begins to change. Sunspots are places where intense magnetic loops -- hundreds of times stronger than the ambient dipole field -- poke through the photosphere.

" Meridional flows on the Sun's surface carry magnetic fields from mid-latitude sunspots to the Sun's poles," explains Hathaway. "The poles end up flipping because these flows transport south-pointing magnetic flux to the north magnetic pole, and north-pointing flux to the south magnetic pole." The dipole field steadily weakens as oppositely-directed flux accumulates at the Sun's poles until, at the height of solar maximum, the magnetic poles change polarity and begin to grow in a new direction.

Hathaway noticed the latest polar reversal in a "magnetic butterfly diagram." Using data collected by astronomers at the U.S. National Solar Observatory on Kitt Peak, he plotted the Sun's average magnetic field, day by day, as a function of solar latitude and time from 1975 through the present. The result is a sort of strip chart recording that reveals evolving magnetic patterns on the Sun's surface. "We call it a butterfly diagram," he says, "because sunspots make a pattern in this plot that looks like the wings of a butterfly."

In the butterfly diagram, pictured below, the Sun's polar fields appear as strips of uniform color near 90 degrees latitude. When the colors change (in this case from blue to yellow or vice versa) it means the polar fields have switched signs.

Above: In this "magnetic butterfly diagram," yellow regions are occupied by south-pointing magnetic fields; blue denotes north. At mid-latitudes the diagram is dominated by intense magnetic fields above sunspots. During the sunspot cycle, sunspots drift, on average, toward the equator -- hence the butterfly wings. The uniform blue and yellow regions near the poles reveal the orientation of the Sun's underlying dipole magnetic field.

The ongoing changes are not confined to the space immediately around our star, Hathaway added. The Sun's magnetic field envelops the entire solar system in a bubble that scientists call the "heliosphere." The heliosphere extends 50 to 100 astronomical units beyond the orbit of Pluto. Inside it is the solar system -- outside is interstellar space.

"Changes in the Sun's magnetic field are carried outward through the heliosphere by the solar wind," explains Steve Suess, another solar physicist at the Marshall Space Flight Center. "It takes about a year for disturbances to propagate all the way from the Sun to the outer bounds of the heliosphere."

Because the Sun rotates (once every 27 days) solar magnetic fields corkscrew outwards in the shape of an Archimedian spiral. Far above the poles the magnetic fields twist around like a child's Slinky toy.

Left: Steve Suess (NASA/MSFC) prepared this figure, which shows the Sun's spiraling magnetic fields from a vantage point ~100 AU from the Sun.

Because of all the twists and turns, "the impact of the field reversal on the heliosphere is complicated," says Hathaway. Sunspots are sources of intense magnetic knots that spiral outwards even as the dipole field vanishes. The heliosphere doesn't simply wink out of existence when the poles flip -- there are plenty of complex magnetic structures to fill the void.

Or so the theory goes.... Researchers have never seen the magnetic flip happen from the best possible point of view -- that is, from the top down.

But now, the unique Ulysses spacecraft may give scientists a reality check. Ulysses, an international joint venture of the European Space Agency and NASA, was launched in 1990 to observe the solar system from very high solar latitudes. Every six years the spacecraft flies 2.2 AU over the Sun's poles. No other probe travels so far above the orbital plane of the planets.

"Ulysses just passed under the Sun's south pole," says Suess, a mission co-Investigator. "Now it will loop back and fly over the north pole in the fall."

Right: Following an encounter with Jupiter in 1992, the Ulysses spacecraft went into a high polar orbit. It's maximum solar latitude is 80.2 degrees south. [more]

"This is the most important part of our mission," he says. Ulysses last flew over the Sun's poles in 1994 and 1996, during solar minimum, and the craft made several important discoveries about cosmic rays, the solar wind, and more. "Now we get to see the Sun's poles during the other extreme: Solar Max. Our data will cover a complete solar cycle."

Cosmic rays 'linked to clouds'

The influence of clouds on climate change is poorly understood

By Alex Kirby - BBC News Online environment correspondent - Saturday, 19 October, 2002, 12:36 GMT 13:36 UK

German scientists have found a significant piece of evidence linking cosmic rays to climate change. They have detected charged particle clusters in the lower atmosphere that were probably caused by the space radiation. They say the clusters can lead to the condensed nuclei which form into dense clouds.

Clouds play a major, but as yet not fully understood, role in the dynamics of the climate, with some types acting to cool the planet and others warming it up. The amount of cosmic rays reaching Earth is largely controlled by the Sun, and many solar scientists believe the star's indirect influence on Earth's global climate has been underestimated.

Some think a significant part of the global warming recorded in 20th Century may in fact have its origin in changes in solar activity - not just in the increase in fossil-fuel-produced greenhouse gases.

First evidence found

The German team, from the Max Planck Institute of Nuclear Physics in Heidelberg, used a large ion mass spectrometer mounted on an aircraft.

They say their measurements "have for the first time detected in the upper troposphere large positive ions with mass numbers up to 2500". They conclude: "Our observations provide strong evidence for the ion-mediated formation and growth of aerosol particles in the upper troposphere."

The scientists report their findings in Geophysical Research Letters, a journal of the American Geophysical Union. They support the theory that cosmic rays can influence climate change and affect cloud albedo - the ability of clouds to reflect light.

In and out

The importance of clouds in the climate system is described by the Tyndall Centre for Climate Change Research, at the UK's University of East Anglia (UEA). It says: "Clouds strongly influence the passage of radiation through the Earth's atmosphere. "They reflect some incoming short-wave solar radiation back into space and absorb some outgoing long-wave terrestrial radiation: producing cooling and warming effects, respectively."

And UEA's Climatic Research Unit spells out the complexity of clouds' role in climate change. It says: "The cloud feedback may be large, yet not even its sign is known. "Low clouds tend to cool, high clouds tend to warm. High clouds tend to have lower albedo and reflect less sunlight back to space than low clouds.

Confusion confounded

"Clouds are generally good absorbers of infrared, but high clouds have colder tops than low clouds, so they emit less infrared spacewards. "To further complicate matters, cloud properties may change with a changing climate, and human-made aerosols may confound the effect of greenhouse gas forcing on clouds. "Depending on whether and how cloud cover changes, the cloud feedback could almost halve or almost double the warming."

Many scientists agree that the Earth's surface appears to be warming, while low atmosphere temperatures remain unchanged.

Missing link

Research published last August suggested the rays might cause changes in cloud cover which could explain the temperature conundrum.

The discrepancy in temperatures has led some scientists to argue that the case for human-induced climate change is weak, because our influence should presumably show a uniform temperature rise from the surface up through the atmosphere.

Although researchers have proposed that changes in cloud cover could help to explain the discrepancy, none had been able to account for the varying heat profiles. But the study suggested that cosmic rays, tiny charged particles which bombard all planets with varying frequency depending on solar wind intensity, could be the missing link. - BBC

Black holes: The ultimate quantum computers?

10:17 13 March 2006 - NewScientist.com news - Maggie McKee

Nearly all of the information that falls into a black hole escapes back out, a controversial new study argues. The work suggests that black holes could one day be used as incredibly accurate quantum computers - if enormous theoretical and practical hurdles can first be overcome.

Black holes are thought to destroy anything that crosses a point of no return around them called an "event horizon". But in the 1970s, Stephen Hawking used quantum mechanics to show black holes do emit radiation, which eventually evaporates them away completely.

Originally, he argued that this "Hawking radiation" is so random that it could carry no information out about what had fallen into the black hole. But this conflicted with quantum mechanics, which states that quantum information can never be lost. Eventually, Hawking changed his mind and in 2004 famously conceded a bet, admitting that black holes do not destroy information.

But the issue is far from settled, says Daniel Gottesman of the Perimeter Institute in Waterloo, Canada. "Hawking has changed his mind, but a lot of other people haven't," he told New Scientist. "There are still a lot of questions about what's really going on."

Quantum entanglement

Now, Seth Lloyd of the Massachusetts Institute of Technology in the US, has used a controversial quantum model called final-state projection to try to solve the paradox. The model holds that under certain extreme circumstances - such as the intense gravitational field of a black hole, objects that would ordinarily have several options for their behaviour have only one. For example, a black hole could cause a coin thrown into it to always come up "heads".

This allows information to escape from a black hole without any ambiguity about how to interpret it. The information escapes through a quantum process called entanglement, in which objects are not independent if they have interacted with each other or come into being through the same process. They become linked, or entangled, such that changing one invariably affects the other, no matter how far apart they are.

In black holes, Hawking radiation arises just inside the event horizon and has two components - one that leaves the black hole and another that falls towards the point-like singularity that is the black hole itself.

These components are entangled, so when matter that has been sucked into the black hole interacts with the infalling Hawking radiation at the singularity, the interaction instantaneously produces a change in the Hawking radiation that has escaped the black hole. Because the final-state projection model forces this interaction to behave in only one way, this radiation therefore carries information about material inside the black hole.

Smooshed up

Gottesman and colleague John Preskill of the California Institute of Technology in Pasadena, US, found that previous calculations by other researchers using this model allowed information to escape for only certain interactions between the infalling matter and the infalling Hawking radiation. Now, Lloyd has calculated that the process is quite robust - the random nature of these interactions means the system is almost perfectly entangled.

That suggests the outgoing Hawking radiation carries away nearly all of the information of the matter - such as a spaceship - that falls into the black hole. According to Lloyd, the most that could be lost is half a quantum unit of information, or 0.5 qubit.

"Passengers on a spaceship would like some guarantee that when they fall into this black hole and get smooshed into the singularity, they can be recreated as it evaporates," Lloyd told New Scientist. "With a few simple precautions, the travellers would be almost exactly the same, with less than an atom of difference."

Lloyd also says the work suggests black holes could be used as quantum computers. "We might be able to figure out a way to essentially program the black hole by putting in the right collection of matter," he says.

Mission implausible

But both applications would require an understanding of the properties of specific black holes, says Gottesman. "And you'd have to collect every little piece of Hawking radiation because the spaceship would get spread out with everything that fell into the black hole - ever," Gottesman says. "So you'd have to sort out which bits were the spaceship and which bits were other things. It's implausible."

Lloyd agrees. Understanding how to decode the outgoing Hawking radiation will require researchers to weave together quantum physics and general relativity into a seamless theory of quantum gravity - a goal that has so far proved elusive. "Until we understand quantum gravity, we're not going to be running Linux on a black hole," he jokes.

But beyond the practical difficulties, Gottesman says the work has a more serious theoretical flaw. Despite the fact that just half a qubit of information is lost, "from a fundamental point of view, there is no real difference between a little bit of information being lost and a lot being lost," he says.

"In standard quantum mechanics, no information is ever lost, so if he is right, quantum mechanics would have to be revised to allow information loss. We have no real idea of what theory could take its place."

Journal reference: Physical Review Letters (vol 96, no 061302) - New Scientist

Brightest Galactic Flash Ever Detected Hits Earth

By Robert Roy Britt - Senior Science Writer 18 February, 2005

A huge explosion halfway across the galaxy packed so much power it briefly altered Earth's upper atmosphere in December, astronomers said Friday. No known eruption beyond our solar system has ever appeared as bright upon arrival. But you could not have seen it, unless you can top the X-ray vision of Superman: In gamma rays, the event equaled the brightness of the full Moon's reflected visible light.

The blast originated about 50,000 light-years away and was detected Dec. 27. A light-year is the distance light travels in a year, about 6 trillion miles (10 trillion kilometers).

The commotion was caused by a special variety of neutron star known as a magnetar. These fast-spinning, compact stellar corpses -- no larger than a big city -- create intense magnetic fields that trigger explosions. The blast was 100 times more powerful than any other similar eruption witnessed, said David Palmer of Los Alamos National Laboratory, one of several researchers around the world who monitored the event with various telescopes.

Tsunami Connection?

Several readers wondered if the magnetar blast could be related to the December tsunami. Scientists have made no such connection. The blast affected Earth's ionosphere, which is routinely affected to a greater extent by changes in solar activity.

"Had this happened within 10 light-years of us, it would have severely damaged our atmosphere and possibly have triggered a mass extinction," said Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics (CfA).

There are no magnetars close enough to worry about, however, Gaensler and two other astronomers told SPACE.com. But the strength of the tempest has them marveling over the dying star's capabilities while also wondering if major species die-offs in the past might have been triggered by stellar explosions.

'Once-in-a-lifetime'

The Sun is a middle-aged star about 8 light-minutes from us. Its tantrums, though cosmically pitiful compared to the magnetar explosion, routinely squish Earth's protective magnetic field and alter our atmosphere, lighting up the night sky with colorful lights called aurora. Solar storms also alter the shape of Earth's ionosphere, a region of the atmosphere 50 miles (80 kilometers) up where gas is so thin that electrons can be stripped from atoms and molecules -- they are ionized -- and roam free for short periods. Fluctuations in solar radiation cause the ionosphere to expand and contract.

"The gamma rays hit the ionosphere and created more ionization, briefly expanding the ionosphere," said Neil Gehrels, lead scientist for NASA's gamma-ray watching Swift observatory.

Gehrels said in an email interview that the effect was similar to a solar-induced disruption but that the effect was "much smaller than a big solar flare." Still, scientists were surprised that a magnetar so far away could alter the ionosphere.

"That it can reach out and tap us on the shoulder like this, reminds us that we really are linked to the cosmos," said Phil Wilkinson of IPS Australia, that country's space weather service. "This is a once-in-a-lifetime event," said Rob Fender of Southampton University in the UK. "We have observed an object only 20 kilometers across [12 miles], on the other side of our galaxy, releasing more energy in a tenth of a second than the Sun emits in 100,000 years."

Some researchers have speculated that one or more known mass extinctions hundreds of millions of years ago might have been the result of a similar blast altering Earth's atmosphere. There is no firm data to support the idea, however. But astronomers say the Sun might have been closer to other stars in the past.

A similar blast within 10 light-years of Earth "would destroy the ozone layer," according to a CfA statement, "causing abrupt climate change and mass extinctions due to increased radiation."

The all-clear has been sounded, however.

"None of the known sample [of magnetars] are closer than about 4,000-5,000 light years from us," Gaensler said. "This is a very safe distance."

Cause a mystery

Researchers don't know exactly why the burst was so incredible. The star, named SGR 1806-20, spins once on its axis every 7.5 seconds, and it is surrounded by a magnetic field more powerful than any other object in the universe.

"We may be seeing a massive release of magnetic energy during a 'starquake' on the surface of the object," said Maura McLaughlin of the University of Manchester in the UK.

Another possibility is that the magnetic field more or less snapped in a process scientists call magnetic reconnection. Gamma rays are the highest form of radiation on the electromagnetic spectrum, which includes X-rays, visible light and radio waves too. The eruption was also recorded by the National Science Foundation's Very Large Array of radio telescopes, along with other European satellites and telescopes in Australia.

Explosive details

A neutron star is the remnant of a star that was once several times more massive than the Sun. When their nuclear fuel is depleted, they explode as a supernova. The remaining dense core is slightly more massive than the Sun but has a diameter typically no more than 12 miles (20 kilometers). Millions of neutron stars fill the Milky Way galaxy. A dozen or so are ultra-magnetic neutron stars -- magnetars. The magnetic field around one is about 1,000 trillion gauss, strong enough to strip information from a credit card at a distance halfway to the Moon, scientists say.

Of the known magnetars, four are called soft gamma repeaters, or SGRs, because they flare up randomly and release gamma rays. The flare on SGR 1806-20 unleashed about 10,000 trillion trillion trillion watts of power.

"The next biggest flare ever seen from any soft gamma repeater was peanuts compared to this incredible Dec. 27 event," said Gaensler of the CfA. - space.com

Gamma ray burst may have wiped out sea life

JOHN VON RADOWITZ - 11th April 2005

A MIGHTY blast of radiation from an exploding star may have wiped out much of life in the sea 450 million years ago, scientists claim. New research suggests that a gamma ray burst could have been responsible for the Ordovican mass extinction in which 60 per cent of all marine invertebrates died.

Gamma ray bursts are immensely powerful surges of radiation. Many are thought to have been caused by the explosions of stars over 15 times more massive than the Sun. A burst creates two beams of gamma ray energy that race off across space in opposite directions.

The Ordovican mass extinction can be explained by a gamma ray burst within 6,000 light years of Earth, say scientists from the US space agency NASA and the University of Kansas.

Dr Adrian Melott, from the university, said: "A gamma ray burst originating within 6,000 light years from Earth would have a devastating effect on life. We don’t know exactly when one came, but we’re rather sure it did come - and left its mark."

Such a burst would strip the Earth of its protective ozone layer, allowing deadly ultraviolet radiation to pour down from the Sun.

Computer models showed that up to half the ozone layer could be destroyed within weeks. Five years later, at least 10 per cent would still be missing.

"What’s surprising is that just a ten-second-burst can cause years of devastating ozone damage," said Dr Melott.

The researchers calculated that while sea creatures living at depths of several feet or more would escape harm, plankton and other life near the surface would be destroyed. Plankton is at the bottom of the marine food chain, providing food for animals which in turn are preyed on by larger species. The knock-on effects of wiping out plankton would have reverberated through the whole ecosystem. Scientists had previously assumed that an ice age caused the Ordovican extinction. - scotsman.com

Cosmic ray link to global warming boosted

10:27 17 August 2004 - Exclusive from New Scientist Print Edition - Jenny Hogan

The controversial idea that cosmic rays could be driving global warming by influencing cloud cover will get a boost at a conference next week. But some scientists dismiss the idea and are worried that it will detract from efforts to curb rising levels of greenhouse gases.

At issue is whether cosmic rays, the high-energy particles spat out by exploding stars elsewhere in the galaxy, can affect the temperature on Earth. The suggestion is that cosmic rays crashing into the atmosphere ionise the molecules they collide with, triggering cloud formation.

If the flux of cosmic rays drops, fewer clouds will form and the planet will warm up. No one yet understands the mechanism, which was first described in the late 1990s. But what makes it controversial is that climate models used to predict the consequences of rising levels of greenhouse gases do not allow for the effect, and may be inaccurate.

Some proponents of the theory argue that changes in the number of cosmic rays reaching Earth can explain past climate change as well as global warming today. Nir Shaviv of the Hebrew University in Jerusalem, Israel, and Jan Veizer of the University of Ottawa in Ontario, Canada, claimed in 2003 that changes in cosmic-ray flux are the major reason for temperature changes over the past 500 million years (GSA Today, July 2003, p 4).

They argued that changes in carbon dioxide levels over the same period had a much smaller effect on temperature than previously assumed, suggesting that today's soaring levels of the greenhouse gas may have less impact than scientists anticipate. "It makes you think maybe it's a waste implementing the Kyoto Protocol and losing all those trillions of dollars," says Shaviv.

Deflected rays

After being strongly criticised, Shaviv will defend his calculations next week at the Western Pacific Geophysics Meeting in Honolulu, Hawaii. The idea will also be backed up by Nigel Marsh of the Danish Space Research Institute in Copenhagen.

Marsh and his colleagues looked at satellite images of low-altitude clouds from the past 20 years. They noticed that the pattern of global cloud cover varied over a time scale of roughly 10 years, and found a correlation with the 11-year sunspot cycle.

The more sunspot activity there is, the greater the strength of the sun's magnetic field. And cosmic rays are deflected by this field, so the stronger it is, the fewer rays reach the Earth, and the lower the cloud cover.

The Copenhagen team also found that clouds were scarce near the equator and thicker towards the tropics. According to Marsh, this is because cosmic rays have a hard time punching through Earth's magnetic field at the equator, but can leak in through the relatively weaker field nearer the poles.

"Artificially enhanced"

But some climatologists believe that people are pushing the hypothesis that the Sun's magnetic field affects climate on Earth even though they lack the data to back it up.

Gavin Schmidt, a climate scientist from the NASA Goddard Institute for Space Studies in New York, was one of 11 authors who published a letter in January criticising Shaviv's paper, arguing that the researchers "applied several adjustments to the data to artificially enhance the correlation" (EOS, vol 85, p 38).

"The main proponents are so wedded to the hypothesis that they think they just have to find the right correlation and then they are done," he says.

The idea that cosmic rays influence climate "is one of only a few truly new theories in Earth science," says Steven Lloyd, an atmospheric scientist from the Johns Hopkins University in Laurel, Maryland, who will chair the session on cosmic rays and climate next week. But "the political implications of the research muddy the waters", he says. - new scientist

'No cosmic ray climate effects'

By Alex Kirby BBC News Online environment correspondent - Friday, 23 January, 2004

The principal cause of recent climate change is not cosmic rays but human activities, a group of scientists says. They say an article last year linking cosmic rays and changes in temperature was "scientifically ill-founded". They say the authors' methods were open to doubt and their conclusions wrong, surprising experts with their claims.

In Eos, the journal of the American Geophysical Union, the 11 Earth and space scientists insist that greenhouse gases remain the chief climate suspect.

In the climate mainstream

They say the most important physical processes are well understood, and model calculations and data analyses both conclude the human contribution to the global warming of the 20th Century through increased emissions of carbon dioxide (CO2) and other gases was dominant.

The authors of the Eos article - Cosmic Rays, Carbon Dioxide And Climate - are from Canada, France, Germany, Switzerland and the US.

The research by Nir Shaviv, an astrophysicist, of Hebrew University in Jerusalem, and Jan Veizer, a geologist, of the University of Ottawa and Ruhr University in Germany, was published in July 2003 in the Geological Society of America's journal GSA Today.

It said the Earth's climate was profoundly affected by cosmic rays, high-energy particles from outer space, which normally cool the Earth's surface by helping clouds to form.

But increased solar activity lessens the cosmic rays reaching the Earth, and Shaviv and Veizer suggested this blocking effect had been the dominant cause of global warming over the past century.

No ground given

They said cosmic ray changes accounted for at least 66% of the temperature variation during that period.

The Eos authors, led by Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research, Germany, say the paper by Shaviv and Veizer was "incorrect and based on questionable methodology".

They say the data on cosmic rays and temperature so far in the past are extremely uncertain. They argue that the authors' reconstruction of ancient cosmic rays is based on only 50 meteorites, and say most other experts interpret their significance in a very different way. Arguing that Shaviv and Veizer had in places adjusted the data, "in one case by 40 million years", the Eos team says they did not show any correlation between cosmic rays and climate.

And even if their analysis had been methodologically correct, it says, their work applied to time scales of several million years, while the current climate warming has occurred during just a hundred years, for which completely different mechanisms are relevant.

Dr Shaviv told BBC News Online: "The article in Eos raises general claims without substantiating them with any actual evidence. The few more specific arguments that they bring are simply flawed and easily refuted."

Professor Veizer told BBC News Online: "It's a long story, and the whole issue is politically driven. "We stand by what we said, that there is a correlation between the cosmic ray flux and the temperatures we calculated, though on the details we can disagree." - BBC

Global warming linked to cosmic rays

Ottawa professor admits theory is way out there

Tom Spears, CanWest News Service - Thursday, March 16, 2006

OTTAWA - A prominent University of Ottawa science professor says what we know about global warming is wrong -- that stars, not greenhouse gases, are heating up the Earth. Jan Veizer says high-energy rays from distant parts of space are smashing into our atmosphere in ways that make our planet go through warm and cool cycles. The retired professor (he still holds a research chair and supervises grad students and post-doctoral fellows) knows that to challenge the accepted climate-change theory can lead to a nasty fight. It's a politically and economically loaded topic. Yet, he is speaking out -- a bit nervously -- about his published research.

"Look, maybe I'm wrong," he said in an interview. "But I'm saying, at least let's look at this and discuss it.

High-energy cosmic rays are hitting us all the time. This has been known for a long time. What's new is that a variety of researchers are asking what cosmic rays do to our world and its weather. That includes a theory published last year by the Proceedings of the Royal Society arguing cosmic rays "unambiguously" form clouds and affect our climate.

Prof. Veizer is a leader in geochemistry -- learning about Earth's past by the chemistry preserved in rocks and sediments. The Royal Society of Canada called him "one of the most creative, innovative and productive geoscientists of our times."

He won the 1992 Gottfried Wilhelm Leibniz Prize, worth $2.2-million, the German government's highest prize for research in any field. Yet, for years he held back on his climate doubts. "I was scared," he said. And he still is.

Still, he has published his theory in Geoscience Canada, the journal of the Geological Association of Canada. The article is called "Celestial Climate Driver: A Perspective from Four Billion Years of the Carbon Cycle."

In his paper, he concludes: "Empirical observations on all time scales point to celestial phenomena as the principal driver of climate, with greenhouse gases acting only as potential amplifiers."

The majority of climate scientists still firmly believe that greenhouse gases are to blame. But Prof. Veizer felt uncomfortable with the idea that high levels of carbon dioxide alone are causing hot spells. He looked to geology. As environmental conditions change, different "isotopes" of some chemicals form. These are slightly different forms of any element -- carbon, or oxygen, or less common substances such as beryllium. And these remain frozen in time in ancient rocks, or lake and ocean sediments, or glaciers. (Samples drilled from Antarctic ice go back more than 700,000 years, layer by layer.)

For Prof. Veizer, the idea is that cosmic rays hit gas molecules in the atmosphere and form the nucleus of what becomes a water vapour droplet. These in turn form clouds, reflecting some of the sun's energy back to space and cooling the Earth.

Yet the numbers of cosmic rays vary. Most come from younger stars, which are clustered at some regions in the galaxy through which our solar system has passed its 4.5-billion-year history. As well, our own sun deflects some of these rays away, but the sun's activity grows stronger and weaker. All these factors can change the number of cosmic rays that hit us. - canada.com

Swift Sees an Unusual Gamma Ray Burst

Tue, 28 Feb 2006 - NASA's Swift satellite is continuing to send back surprising information about gamma ray bursts. On February 18, 2006, it discovered something completely unique; a burst that originated 440 million light-years away and lasted about 30 minutes. This event is very similar to the more common bursts that have been seen in the past; however, it was about 25 times closer, and lasted 100 times longer than a typical burst.

The strange cosmic explosion that occured on February 18th. Image credit: SDSS/Swift Click to enlarge

The Swift satellite, whose mission control center is in State College, has detected a cosmic explosion that has sent scientists around the world scrambling to telescopes to document this startling event. Gamma-ray radiation from the source, detected on 18 February and lasting about half an hour, appears to be a precursor to a supernova, which is the death throes of a star much more massive than the Sun. "The observations indicate that this is an incredibly rare glimpse of an initial gamma-ray burst at the beginning of a supernova," said Peter Brown, a Penn State graduate student and a member of the Swift science team.

Astronomers are using Swift, whose science and flight operations are controlled by Penn State from the Mission Operations Center in State College, to continue to observe the event. Scores of satellites and ground-based telescopes also are now trained on the sight, watching and waiting. Amateur astronomers in the northern hemisphere with a good telescope in dark skies also can view the source.

The explosion has the trappings of a gamma-ray burst, the most distant and powerful type of explosion known. This event, however, was about 25 times closer and 100 times longer than the typical gamma-ray burst. "This burst is totally new and unexpected," said Neil Gehrels, Swift principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "This is the type of unscripted event in our nearby universe that we hoped Swift could catch."

The explosion, called GRB 060218 after the date it was discovered, originated in a star-forming galaxy about 440 million light-years away toward the constellation Aries. This is the second-closest gamma-ray burst ever detected, if indeed it is a true burst.

Derek Fox, assistant professor of astronomy and astrophysics at Penn State, who is leading the monitoring effort of GRB 060218 on the Hobby-Eberly Telescope, commented, "This is the burst we've been waiting eight years for," referring to the closest-ever gamma-ray burst, which was detected in 1998. "The special capabilities of Swift, which was not operating in 1998, combined with the intense campaign of ground-based telescopes, should help unravel this mystery," said Fox.

"There are still many unknowns," said Penn State Professor of Astronomy and Astrophysics John Nousek, the Swift mission operations director at Penn State University in University Park, Pennsylvania. The burst of gamma rays lasted for nearly 2,000 seconds; in contrast, most such bursts last a few milliseconds to tens of seconds. The explosion also was surprisingly dim. "This could be a new kind of burst, or we might be seeing a gamma-ray burst from an entirely different angle," he said. The standard theory for gamma-ray bursts is that the high-energy light is beamed in our direction. "This off-angle glance--a profile view, perhaps--has given us an entirely new approach to studying star explosions. Had this burst been farther away, we would have missed it," Nousek explained.

Because the burst was so long, Swift was able to observe the bulk of the explosion with all three of its instruments: the Burst Alert Telescope, which detected the burst; and the X-ray Telescope, and Ultraviolet/Optical Telescope, which provide high-resolution imagery and spectra across a broad range of wavelengths. Penn State lead the development of the X-ray and Ultraviolet/Optical Telescopes.

Scientists will attempt observations with the Hubble Space Telescope and the Chandra X-ray Observatory. Amateur astronomers in dark skies might be able to see the explosion with a 16-inch telescope as it hits 16th-magnitude brightness.

Swift is a NASA mission in partnership with the Italian Space Agency and the Particle Physics and Astronomy Research Council in the United Kingdom; it is managed by NASA Goddard, and Penn State controls its science and flight operations from the Mission Operations Center in University Park, Pennsylvania. - universetoday.com

Unique Explosion: Gamma-ray burst leads astronomers to supernova

Ron Cowen

Using scores of telescopes, astronomers worldwide are chasing one of the most intriguing stellar explosions detected in nearly a decade. The supernova-a catastrophic collapse of a massive star-is one of only a handful of these explosions known to have been heralded by a burst of gamma rays.

The observations confirm that material blasting out from a collapsing star generates a gamma-ray burst. The burst races out into space ahead of the visible, fiery glow from the supernova explosion.

A gamma-ray burst typically lies too far away-billions of light-years-and has an afterglow too bright to permit astronomers to detect the underlying supernova. But the new burst, recorded by NASA's Swift satellite on Feb. 18, resided a relatively close 440 million light-years from Earth. Furthermore, the burst was unusually weak, despite lasting nearly 2,000 seconds-about 100 times as long as the typical burst.

Within 3 minutes of the burst, dubbed GRB 060218, Swift's visible-light telescope pinpointed the source, in the constellation Aries. Then, the race on was on to find the hidden supernova. On Feb. 21, Alicia Soderberg of the California Institute of Technology in Pasadena and her colleagues succeeded, using the large Gemini South Observatory on Cerro Pachón Mountain in Chile. The supernova is expected to reach its peak brightness around March 5, and amateur astronomers in the Northern Hemisphere with a telescope at least 16 inches across have a good chance of viewing the ongoing eruption.

Watching a supernova unfold so soon after the star erupted-particularly one linked so closely to a gamma-ray burst-is only part of the excitement, says Soderberg. Astronomers calculate that this burst packed only about one-hundredth the energy of more-distant bursts. Its low energy was similar to an even closer burst recorded in 1998. Taken together, the two bursts "imply the existence of a significant population of [faint] gamma-ray bursts that go undetected at larger distances," Soderberg says.

These low-energy events could be 30 times as common as more-powerful bursts, calculates theorist Andrew MacFadyen of the Institute for Advanced Study in Princeton, N.J.

In high-energy bursts, a collapsing star expels jets of material at near-light speeds. Chunks within each jet collide to generate the gamma rays. In contrast, lower-energy bursts may originate from a weaker explosion that drives out lower-speed chunks of material in a more diffuse pattern, MacFadyen suggests. When this material smacks into dust and gas surrounding the star, it generates the lower-energy gamma rays. In either case, the collapsing star becomes a black hole or a magnetar, an extremely dense, rapidly spinning star with an enormous magnetic field.

MacFadyen, who has worked on gamma-ray-burst models for more than a decade, doesn't usually do his work from behind a telescope. This time, however, "I'm personally looking to make friends with someone with a telescope because I really want to see a new black hole or magnetar being formed with my own eyes. This is a rare and special opportunity." - sciencenews.org

Next Solar Max Will Be a Big One

Mon, 13 Mar 2006 - We've now reached the Sun's solar minimum; there's not a sunspot anywhere across the surface of our closest star. Give it a few years, though, and it should be anything but quiet. Solar researchers think they understand the long term cycles of solar activity, and they're predicting that the next Solar Maximum - expected to arrive between 2010 and 2012 - will be the strongest in 50 years.

It's official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet.

Like the quiet before a storm.

SOHO Can See Right Through the Sun

Thu, 09 Mar 2006 - NASA researchers have developed a technique that allows them to look right through the Sun to see what's happening on the other side. The Solar and Heliospheric Observatory (SOHO) can trace the sound waves caused by active regions on the opposite side of the Sun. This technique allows the researchers to be more prepared when large sunspots rotate around to face the Earth, and better predict active space weather.

NASA researchers using the Solar and Heliospheric Observatory (SOHO) spacecraft have developed a method of seeing through the sun to the star's far side. The sun's far side faces away from the Earth, so it is not directly observable by traditional techniques.

"This new method allows more reliable advance warning of magnetic storms brewing on the far side that could rotate with the sun and threaten the Earth," said NASA-supported scientist Phil Scherrer of Stanford University, Stanford, Calif.

Magnetic storms resulting from violent solar activity disrupt satellites, radio communications, power grids and other technological systems on Earth. Advance warning can help planners prepare for operational disruptions. The sun rotates once every 27 days, as seen from Earth, and this means the evolution of active regions on the far side of the sun previously has not been detectable.

Many of these storms originate in groups of sunspots, or active regions - areas with high concentration of magnetic fields. Active regions situated on the near side of the sun, the one facing the Earth, can be observed directly. However, traditional methods provided no information about active regions developing on the other side of the sun. Knowing whether there are large active regions on the opposite side of the sun may greatly improve forecast of potential magnetic storms.

The new observation method uses SOHO's Michelson Doppler Imager (MDI) instrument to trace sound waves reverberating through the sun to build a picture of the far side.

The sun is filled with many kinds of sound waves caused by the convective (boiling) motion of gas in its surface layers. The far side imaging method compares the sound waves that emanate from each small region on the far side with what was expected to arrive at that small region from waves that originated on the front side. An active region reveals itself because its strong magnetic fields speed up the sound waves. The difference becomes evident when sound waves originating from the front side and from the back side get out of step with one another.

"The original far-side imaging method only allowed us to see the central regions, about one-quarter to one-third of its total area," Scherrer said. "The new method allows us to see the entire far side, including the poles." Scherrer started an effort to use the new method to create full far-side images from archived MDI data collected since 1996. The project was completed in December 2005.

Douglas Biesecker of the National Oceanic and Atmospheric Administration's Space Environment Center, Boulder, Colo., said, "With the new far side photo album going back to 1996, we can discover identifying characteristics of active regions. This will improve our ability to distinguish real active regions."

SOHO is a cooperative project between the European Space Agency and NASA. For SOHO information and images on the Web, visit: www.nasa.gov/vision/universe/solarsystem/soho_xray.html

Strange Helix-Shaped Nebula Discovered

Wed, 15 Mar 2006 - Astronomers have discovered an unusual helix-shaped nebula near the centre of the Milky Way. This peculiar nebula stretches 80 light years, and looks like the classic image of a DNA molecule. The nebula formed because it's so close to the supermassive black hole at the heart of the Milky Way, which has a very powerful magnetic field. This field isn't as powerful as the one surrounding the Sun, but it's enormous, containing a tremendous amount of energy. It's enough to reach out this incredible distance and twist up this gas cloud with its field lines.

Astronomers report an unprecedented elongated double helix nebula near the center of our Milky Way galaxy, using observations from NASA's Spitzer Space Telescope. The part of the nebula the astronomers observed stretches 80 light years in length. The research is published March 16 in the journal Nature.

"We see two intertwining strands wrapped around each other as in a DNA molecule," said Mark Morris, a UCLA professor of physics and astronomy, and lead author. "Nobody has ever seen anything like that before in the cosmic realm. Most nebulae are either spiral galaxies full of stars or formless amorphous conglomerations of dust and gas - space weather. What we see indicates a high degree of order."

The double helix nebula is approximately 300 light years from the enormous black hole at the center of the Milky Way. (The Earth is more than 25,000 light years from the black hole at the galactic center.)

The Spitzer Space Telescope, an infrared telescope, is imaging the sky at unprecedented sensitivity and resolution; Spitzer's sensitivity and spatial resolution were required to see the double helix nebula clearly.

"We know the galactic center has a strong magnetic field that is highly ordered and that the magnetic field lines are oriented perpendicular to the plane of the galaxy," Morris said. "If you take these magnetic field lines and twist them at their base, that sends what is called a torsional wave up the magnetic field lines.

"You can regard these magnetic field lines as akin to a taut rubber band," Morris added. "If you twist one end, the twist will travel up the rubber band."

Offering another analogy, he said the wave is like what you see if you take a long loose rope attached at its far end, throw a loop, and watch the loop travel down the rope.

"That's what is being sent down the magnetic field lines of our galaxy," Morris said. "We see this twisting torsional wave propagating out. We don't see it move because it takes 100,000 years to move from where we think it was launched to where we now see it, but it's moving fast - about 1,000 kilometers per second - because the magnetic field is so strong at the galactic center - about 1,000 times stronger than where we are in the galaxy's suburbs."

A strong, large-scale magnetic field can affect the galactic orbits of molecular clouds by exerting a drag on them. It can inhibit star formation, and can guide a wind of cosmic rays away from the central region; understanding this strong magnetic field is important for understanding quasars and violent phenomena in a galactic nucleus. Morris will continue to probe the magnetic field at the galactic center in future research.

This magnetic field is strong enough to cause activity that does not occur elsewhere in the galaxy; the magnetic energy near the galactic center is capable of altering the activity of our galactic nucleus and by analogy the nuclei of many galaxies, including quasars, which are among the most luminous objects in the universe. All galaxies that have a well-concentrated galactic center may also have a strong magnetic field at their center, Morris said, but so far, ours is the only galaxy where the view is good enough to study it.

Morris has argued for many years that the magnetic field at the galactic center is extremely strong; the research published in Nature strongly supports that view.

The magnetic field at the galactic center, though 1,000 times weaker than the magnetic field on the sun, occupies such a large volume that it has vastly more energy than the magnetic field on the sun. It has the energy equivalent of 1,000 supernovae.

What launches the wave, twisting the magnetic field lines near the center of the Milky Way? Morris thinks the answer is not the monstrous black hole at the galactic center, at least not directly.

Orbiting the black hole like the rings of Saturn, several light years away, is a massive disk of gas called the circumnuclear disk; Morris hypothesizes that the magnetic field lines are anchored in this disk. The disk orbits the black hole approximately once every 10,000 years.

"Once every 10,000 years is exactly what we need to explain the twisting of the magnetic field lines that we see in the double helix nebula," Morris said.

Co-authors on the Nature paper are Keven Uchida, a former UCLA graduate student and former member of Cornell University's Center for Radiophysics and Space Research; and Tuan Do, a UCLA astronomy graduate student. Morris and his UCLA colleagues study the galactic center at all wavelengths.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for the agency's Science Mission Directorate. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology. JPL is a division of Caltech. NASA funded the research. - universetoday.com