Magnetically, Earth and sun have a lot in common. "Both the sun's and Earth's magnetic poles are constantly on the move, and they occasionally do a complete flip, with N and S changing places." This flipping happens on every "how many years" on the sun and on every "how many years" on earth?

Hi Mozart,
According to Wikipedia, the sun's magnetic poles reverse themselves every 11 years.

The earth's poles reverse, on the other hand, every 250,000 years on average, again the source here is Wikipedia :

"Based upon the study of lava flows of basalt throughout the world, it has been proposed that the Earth's magnetic field reverses at intervals, ranging from tens of thousands to many millions of years, with an average interval of approximately 250,000 years. The last such event, called the Brunhes-Matuyama reversal, is theorized to have occurred some 780,000 years ago. "

While I was looking at this, I also found this really interesting link to an article in The Observer from 2002 which says that the earth's magnetic force is weakening considerably:


'Earth's magnetic field has disappeared many times before - as a prelude to our magnetic poles flipping over, when north becomes south and vice versa,' said Dr Alan Thomson of the British Geological Survey in Edinburgh.
'Reversals happen every 250,000 years or so, and as there has not been one for almost a million years, we are due one soon.'

Good answer Dance girl. My source ,Nasa, claims every 300,000 years for earth, close enough. Thanx for the link.

Karrow tod me that she gets a headache every time this happens.

One headache every 11 years is not bad.