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Science

Sun's magnetic flip: 5 facts and myths about solar activity

Scientists are watching closely as the sun's magnetic field is set to flip, an event that occurs every 10 to 13 years. CBC News looks at some facts and myths related to solar activity.

Sun will soon reverse its magnetic field

As scientistskeepa close eye on the suns impendingmagnetic flip,Canadians, it seems, will be keeping a close eye on any new developments.

News that the sun is reachingthe midpoint of its solar cycle the peak moment at which it is expected to reverse its magnetic field became the most-viewed story on CBCNews.ca. Since there seems to be a keen interest in solar flares and solar cycles,here are some other interesting facts, or myths, related to solar activity.

1. Earth's magneticfield also flips

While the sun's magnetic field flips about every 10 to 13 years, the Earth's own field also flips, meaning that a compass that points to the north would eventually turn to the south.

But this happens much less frequently. Scientists estimate a flip occurs, on average, once every 200,000 years (although the last flip is said to have occurred 780,000 years ago). However, the process can take anywhere from 1,000 years to 10,000 years.

Although the flip would require some adaptation by humans, animals that use the Earth's magnetic field for directionscould be affected, the British Geological Societysaid.

"Assuming that a reversal takes a number of thousand years, that is, over many generations of each species, each animal may well adapt to the changing magnetic environment, or develop different methods of navigation."

2. Can a solar flare wipe out the Earth?

The sun's magnetic flip is expected to increase the chance of significant solar flares, whichareeruptions ofmagnetic energy from the suns surface. But these solar flares, when interactingwithEarth's magnetic field, canknockoutman-made satellites and power grids, affectnavigation equipmenton airplanes, and interferewith other electronics and communications systems.

In 1989, for example, a geomagnetic storm knocked outthe Hydro-Qubec power grid and left millions ofpeoplewithoutelectricityfor up to ninehours.

Some have expressed concerns thata "killer solar flare" could destroy earth. But scientists say those fears are unfoundedbecause the Earth's thick atmosphere stops radiation produced by a solar flare.

"Most importantly, however, there simply isnt enough energy in the sun to send a killer fireball 93 million miles to destroy Earth," NASA said in a past statement."Even at their worst, the sun's flares are not physically capable of destroying Earth."

3. But abad geomagnetic stormcan cause a lot of economic damage

A study by the National Academy of Sciences, titledSevere Space Weather Events Understanding Societal and Economic Impacts, estimated that depending on the damage, societal and economic costsof a "severe geomagnetic storm scenario" could reach up to $1 trillion to $2 trillion with a recovery time of four to 10 years.

To put those figures into perspective, the costs of North America's northeast blackout in 2003 were estimated at $4 billion to $10 billion.Hurricane Katrina costs were estimated between $81 billion to $125 billion.

4. Sunspots affect the stock market?

Some market analysts believe there is a correlation betweensunspot activity and financial markets and that the former may have an effect on the latter. For example,William Herschelbelieved the number of sunspots affected the price of wheat grain. Some analysts insistthat solar activity has an effect on human emotions. This, they say, also impactsmarkets. So increased high intensity sunspot activity leads people to buy more andcausemarkets to rise and conversely,lower sunspot activity causes markets to go down. But the theory is dismissed by most scientists and economists.

5. Solar flares causing earthquakes?

For years, many have suggested that solar activity, in particular solar flares may cause or be linked to increased earthquake activity. But a recent study by researchers from the U.S. Geological Survey found no evidence of any correlation.

Researchers examined if there was a relationship between increased solar activity and the number of earthquakes.

"There have been some earthquakes like the 9.5 magnitude Chile quake in 1960 where, sure enough, there were more sunspots and more geomagnetic activity than on average, Jeffrey Love, the leading researcher of the study, told Planet Earth Online. But then for the Alaska earthquake in 1964 everything was lower than normal. Theres no obvious pattern between solar activity and seismicity, so our results were inconclusive.