well first nof all what are cosmic rays?
here's a much better explaination i found rather than me tryin to tell you

Cosmic rays are tiny particles, mostly protons, that slam into the Earth's atmosphere at various levels of energy. Billions of cosmic rays are slamming into the Earth every second, most of them with a quite low energy. However, every once in a while cosmic rays with extreme levels of energy impact the Earth. The most powerful yet recorded was a single proton with an energy of 50 J, roughly equivalent to a baseball pitch. Scientists are at a loss to explain how some of the most energetic rays got their energy.
Although they are called "cosmic rays," it should be noted that cosmic rays are point-like particles, not rays. Aside from protons, which make up 90% of all cosmic rays, there are also helium nuclei, also known as alpha particles, which make up another 9%, and electrons which make up the remaining 1%.

Outer space is filled with a bath of fast-moving particles, known as the cosmic ray flux. Cosmic rays are called ionizing radiation because they have the tendency to impact molecules with such force that they knock the electrons off their constituent atoms, creating destructive ions. A piece of biomaterial left unprotected for long enough in the cosmic environment would turn into Swiss cheese. This is one of the greatest challenges for human space colonization, and all space colony designs feature massive shielding to repel cosmic rays.

Cosmic rays get their oomph from high-energy cosmic objects and events, such as neutron stars, supernovae, and black holes. Most cosmic rays originate from within our own galaxy, where they are belched out by supernovae, or launched like a slingshot from the steep gravity well of a black hole. In fact, the presence of certain power levels of cosmic rays is evidence that black holes really exist.

One of the highest levels of the Earth's atmosphere is known as the ionosphere, because it is constantly being ionized by incoming cosmic rays, along with solar radiation. The thermosphere, which is a subset of the ionosphere, experiences heating of up to thousands of degrees due to ionizing radiation, but because the particle density here is relatively low, it wouldn't feel that warm if you were to visit there.

The most energetic cosmic rays come from super high-energy events outside our galaxy, and provide a rare window into the workings of the wider universe. Physicists build multi-million dollar facilities to study the cosmic ray flux in detail.

What are the health effects?

They are everywhere, and several dozen slam into your body every second. These cosmic rays are too low-energy to cause any serious health effects, aside from a few genetic mutations, and cosmic rays are in fact one of the drivers of evolution. Your body receives about 2.4 mSv (milliSieverts) of radiation caused by the effects of cosmic rays every year. For comparison, it takes about 1 Sievert of radiation in a short time to cause nausea, and about 2-6 Sieverts to cause death.

The health effects of cosmic rays change at higher altitudes, where the cosmic ray flux increases exponentially up to an altitude of about 15 km (9 mi), then drops off rapidly. Because of this, people who spend a lot of time at high altitudes, like airline pilots, stewardesses, and Air Force test pilots, experience dozens of times the effects of cosmic rays that people on the ground do. This is still well below the career limit of 1-4 Sv recommended by the National Council on Radiation Protection and Measurements. The cosmic ray flux is low enough in the Earth's atmosphere that exposure only becomes an issue in space.

On the International Space Station, 350 km (217 mi) above the surface of the Earth, astronauts experience the effects of cosmic rays hundreds of times more numerous than those experienced by people on the ground. The Earth's atmosphere is such an effective insulator that barely any particles actually make it to the ground, and most of what people are exposed to is secondary radiation from collisions in the upper atmosphere. On space stations, astronauts are exposed to primary radiation. However, people have spent more than a year in space with no ill effects of cosmic rays, and it seems plausible that indefinitely long stays are possible.

Then there's the burning question,Yes what about our weakening magnetic field?

great article here on this and solar cycle24,maybe youv'e read it.

New scientific discoveries are indicating that this next solar flare cycle could potentially be powerful enough to distrupt our planet's entire electric grid. In this report, I will document the number of changes taking place with our magnetic field, the sun and our solar system while expaining some of the concerns that today's leading scientists have voiced. I will also be examining how humankind may also be affected energically.
What is Electromagnetic Pollution?
TV, cell phone towers, power lines, and house appliances—while they make lives more convenient for some, they also contribute to polluting our electromagnetic atmosphere. A growing number of scientists, health care professionals, and concerned citizens argue that these invisible frequencies are responsible for a host of various health problems. Meanwhile, the largest polluter has gone unnoticed: the sun. And it's about to fire up again.
Our Plant's Magnetic Field
The magnetosphere is a bubble of magnetism that surrounds Earth and protects us from solar wind. Fortunately, our planet's magnetic field diverts most particles into a circular path around the Earth. Like weather patterns found on Earth, solar wind patterns can change rapidly.

Luckily, our planet's magnetosphere quickly responds to the threat and absorbs the impact, wiggling and jiggling in the process. Geophysicists call this reaction a geomagnetic storm, but because of how it disrupts the Earth's magnetic field, it could also be called electromagnetic pollution. This is when we see the Aurora Borealis in our night skys.
But strange things are happening in both outer and inner space
The Earth's magnetic field has been decreasing. This decrease actually began 2000 years ago, but the rate of decrease suddenly became much more rapid 500 years ago. Now, in the last 20 years or so, the magnetic field has become erratic. Aeronautical maps of the world — which are used to allow airplanes to land using automatic pilot systems — have had to be revised worldwide in order for the automatic pilot systems to work.
Late last year, the Arctic ice cap on the exact spot of the North Pole completely melted for the first time in known history. Green Peace reported that, relative to the winter ice pattern, the cap had previously melted over 300 miles toward the pole, and that late last year both military and civilian ships were able to actually pass directly over the North Pole. It was water. Until now, as far as we know, there has never been a time where the ice was less than ten feet thick. In contrast, the South Pole has an ice cap that is about three miles deep, and yet huge pieces of ice continue to break off and melt.
There is a now a Giant Breach in the Earth's Magnetic Field
NASA's five THEMIS spacecraft have discovered a breach in Earth's magnetic field ten times larger than anything previously thought to exist. When this happens, solar wind can flow in through the opening to "load up" the magnetosphere for powerful geomagnetic storms. Exploring the mystery is a key goal of the THEMIS mission, launched in February 2007.

The big discovery came on June 3, 2007, when the five probes serendipitously flew through the breach just as it was opening. Onboard sensors recorded a torrent of solar wind particles streaming into the magnetosphere, signaling an event of unexpected size and importance. But the breach itself is not the biggest surprise. Researchers are even more amazed and baffled at the unexpected way it forms, overturning long-held ideas of space physics.
"At first I didn't believe it," says THEMIS project scientist David Sibeck of the Goddard Space Flight Center. "This finding fundamentally alters our understanding of the solar wind-magnetosphere interaction." "The opening was huge—four times wider than Earth itself," says Wenhui Li, a space physicist at the University of New Hampshire who has been analyzing the data. Li's colleague Jimmy Raeder, also of New Hampshire, says "1027 particles per second were flowing into the magnetosphere—that's a 1 followed by 27 zeros. This kind of influx is an order of magnitude greater than what we thought was possible."
Scientists Surprised
The size of the breach shocked researchers. "We've seen things like this before," says Li's colleague Jimmy Raeder, "but never on such a large scale. The entire day-side of the magnetosphere was open to the solar wind.
This is changing our understanding of the universe. Space physicists have long believed that holes in Earth's magnetosphere open only in response to solar magnetic fields that point south. The great breach of June 2007, however, opened in response to a solar magnetic field that pointed north.
To the lay person, this may sound like a quibble, but to a space physicist, it is almost seismic. It means that something is happening out there that they didn't predict and that is what has them frightened.
Unexpected Shield Drop
Here is where the scientific understanding our how magnetic field is changing: What is understood today in the scientific community is that the solar wind presses against the Earth's magnetosphere almost directly above the equator where our planet's magnetic field points north. Scientists previously believed that if a bundle of solar magnetism came along, and points north, too, the two fields should reinforce one another strengthening Earth's magnetic defenses and slamming the door shut on the solar wind. In the language of space physics, a north-pointing solar magnetic field is called a "northern IMF" and it is synonymous with shields up.
The big suprise is that when a northern IMF came along, the shields went down. This is completely overturning many scientists understanding of things. As Researchers investigated the tear in the magnetic field, they discovered that twenty times more solar wind passed into the Earth's protective shield when the magnetic fields were aligned. Northern IMF events don't actually trigger geomagnetic storms, notes Raeder, but they do set the stage for storms by loading the magnetosphere with plasma. A loaded magnetosphere is primed for auroras, power outages, and other disturbances that can result when a CME (coronal mass ejection) hits.
This means the impact of sloar flares are twenty times as strong with the magnetic lines are aligned. Earth's and the sun's magnetic fields will be in sync at the solar cycle's peak, expected in 2012. This will cause an influx of solar particles. What the scientists didn’t discuss is the impact on the human bioelectrical system.
The earth's magnetic field impacts climate
The earth's climate has been significantly affected by the planet's magnetic field, according to a Danish study published in January 2009 that could challenge the notion that human emissions are responsible for global warming.
"Our results show a strong correlation between the strength of the earth's magnetic field and the amount of precipitation in the tropics," one of the two Danish geophysicists behind the study, Mads Faurschou Knudsen of the geology department at Aarhus University in western Denmark, told the Videnskab journal.
The results of the study, which has also been published in US scientific journal Geology, lend support to a controversial theory published a decade ago by Danish astrophysicist Henrik Svensmark, who claimed the climate was highly influenced by galactic cosmic ray (GCR) particles penetrating the earth's atmosphere.
What Drives Earth's Magnetic Field?
When an electric current passes through a metal wire, a magnetic field forms around that wire Likewise, a wire passing through a magnetic field creates an electric current within the wire. This is the basic principle that allows electric motors and generators to operate.

In the Earth, the liquid metal that makes up the outer core passes through a magnetic field, which causes an electric current to flow within the liquid metal. The electric current, in turn, creates its own magnetic field—one that is stronger than the field that created it in the first place.
As liquid metal passes through the stronger field, more current flows, which increases the field still further. This self-sustaining loop is known as the geomagnetic dynamo. Material from the liquid outer core slowly "freezes" onto the inner core, releasing heat as it does so. (High pressures within the Earth cause material to freeze at high temperatures.) This heat drives convection cells within the liquid core, which keeps the liquid metal moving through the magnetic field.

Energy is needed to keep the dynamo running. This energy comes from the release of heat from the surface of the solid inner core. Our planet's spinning motion causes the moving liquid metal to spiral, in a way similar to how it affects weather systems on the Earth's surface. These spiraling eddies allow separate magnetic fields to align and combine forces.
Without the effects caused by the spinning Earth, the magnetic fields generated within the liquid core would cancel one another out and result in no distinct north or south magnetic poles.
Rapid changes in the churning movement of Earth's liquid outer core are weakening the magnetic field in some regions of the planet's surface, a new study says

"What is so surprising is that rapid, almost sudden, changes take place in the Earth's magnetic field," said study co-author Nils Olsen, a geophysicist at the Danish National Space Center in Copenhagen.
The findings suggest similarly quick changes are simultaneously occurring in the liquid metal, 1,900 miles (3,000 kilometers) below the surface, he said. Fluctuations in the magnetic field have occurred in several far-flung regions of Earth, the researchers found.
The changes "may suggest the possibility of an upcoming reversal of the geomagnetic field," said study co-author Mioara Mandea, a scientist at the German Research Centre for Geosciences in Potsdam. Earth's magnetic field has reversed hundreds of times over the past billion years, and the process could take thousands of years to complete.
The decline in the magnetic field also is opening Earth's upper atmosphere to intense charged particle radiation, scientists say.

Cosmic Rays are slamming Earth
An international team of researchers has discovered a puzzling surplus of high-energy electrons bombarding Earth from space. The source of these cosmic rays is unknown, but it must be close to the solar system and it could be made of dark matter. Their results are being reported in the Nov. 20th issue of the journal Nature.
"This is a big discovery," says co-author John Wefel of Louisiana State University. "It's the first time we've seen a discrete source of accelerated cosmic rays standing out from the general galactic background." To study the most powerful and interesting cosmic rays, Wefel and colleagues have spent the last eight years flying a series of balloons through the stratosphere over Antarctica.
Their NASA-funded cosmic ray detector found an significant surplus of high-energy electrons. "The source of these exotic electrons must be relatively close to the solar system—no more than a kiloparsec away," says co-author Jim Adams of the NASA Marshall Space Flight Center. Galactic cosmic rays are subatomic particles accelerated to almost light speed by distant supernova explosions and other violent events. They swarm through the Milky Way, forming a haze of high energy particles that enter the solar system from all directions.
Cosmic rays consist mostly of protons and heavier atomic nuclei with a dash of electrons and photons spicing the mix. Why must the source be nearby? Adams explains: "High-energy electrons lose energy rapidly as they fly through the galaxy.
They give up energy in two main ways: (1) when they collide with lower-energy photons, a process called inverse Compton scattering, and (2) when they radiate away some of their energy by spiraling through the galaxy's magnetic field." High-energy electrons are therefore local but the researches cannot pinpoint the source in the sky.
According to the research, this source would need to be within about 3,000 light years of the sun. It could be an exotic object such as a pulsar, mini-quasar, supernova remnant or an intermediate mass black hole.
The Sun
The sun is a massive electromagnetic broadcaster which floods the planets of the solar system with heat, light, UV radiation, and electrically charged particles. The Sun itself has a magnetic field, and that magnetic field creates an "egg" around the Solar System that is known as the "heliosphere." The heliosphere is shaped like a teardrop, with the long, thin end of the drop pointing away from the direction in which we're traveling.

The Sun is the center of our Solar System, and all life that is on this Earth came from the Sun. If there were no Sun, we would not be alive. This is simply scientific fact. And so any changes that occur in or on the Sun will eventually affect every person alive. The solar activity during this last sunspot cycle was greater than anything ever seen before.
The Sun's magnetic field has changed in the last 100 years
One recent study by Dr. Mike Lockwood from Rutherford Appleton National Laboratories in California has been investigating the Sun activity for the last hundred years. He reports that since 1901 the overall magnetic field of the Sun has become stronger by 230 percent. Scientists do not understand what that means for us.

Some of the sunspot activity in this last cycle was greater than anything ever recorded before in history. But scientists claim that they don't understand what means either. "Obviously, the sun is Earth's life blood," said Richard Fisher, director of the Heliophysics division at NASA. "To mitigate possible public safety issues, it is vital that we better understand extreme space weather events caused by the sun's activity."
According to NASA, it is beginning another 11-year cycle of activity
The Sun flips its Magnetic Poles every eleven years. Considering that the Sun is to blame for some unfavorable climate changes on the Earth, the coming decade could spell more trouble for our planet. The years ahead could be intense.
Raeder explains: "We're entering Solar Cycle 24. For reasons not fully understood, CMEs in even-numbered solar cycles (like 24) tend to hit Earth with a leading edge that is magnetized north. Such a CME (coronal mass ejection) should open a breach and load the magnetosphere with plasma just before the storm gets underway. It's the perfect sequence for a really big event