Three European satellites launched Friday on a mission to study why the magnetic field surrounding Earth appears to be weakening.

The four-year study by the European Space Agency will collect data and map the field, which protects the planet (and us) from solar radiation.

Scientists say the field’s strength has weakened by about 15 percent in the last 200 years.

Researchers say that the weakening could be a sign of “polarity reversal” — when the field flips end-to-end, turning north into south. The phenomenon occurs every 200,000 to 300,000 years. But the last time the field flipped was almost 800,000 years ago.

The magnetic field is believed to be generated by the Earth’s molten iron core. The field reaches thousands of miles into space and creates a bubble around the earth. It’s what makes compasses work, and aids everything from navigation systems to animal migrations.

 

What does this mean for humanity?

Well, the discovery by NASA rover Curiosity of evidence that water once flowed on Mars – the most Earth-like planet in the solar system – should intensify interest in what the future could hold for mankind.

The only thing stopping Earth having a lifeless environment like Mars is the magnetic field that shields us from deadly solar radiation and helps some animals migrate, and it may be a lot more fragile and febrile than one might think.

Scientists say earth’s magnetic field is weakening and could all but disappear in as little as 500 years as a precursor to flipping upside down.

It has happened before – the geological record suggests the magnetic field has reversed every 250,000 years, meaning that, with the last event 800,000 years ago, another would seem to be overdue.

“Magnetic north has migrated more than 1,500 kilometres over the past century,” said Conall Mac Niocaill, an earth scientist at Oxford University. “In the past 150 years, the strength of the magnetic field has lessened by 10 percent, which could indicate a reversal is on the cards.”

All ideas of what will happen at this point are pure speculation.  This “flip” may be instantaneous or may take hundreds of years.  The later will definitely lead to the extinction of the human race, but even if it is instantaneous there is no telling what effects the change of polarity will have on our lives.  It is very likely that it in itself can cause life altering changes that kill off mankind as well.  Especially if you look at Mars as an example.