Recent reports note that the Earth’s magnetic field has weakened dramatically in the past couple of centuries and may be about to go to zero in advance of a reversal of the magnetic poles. Such reversals occur naturally every 250,000 years or so according to measurements of iron minerals in core samples and lava flows. However, there hasn’t been a magnetic reversal for over a million years now so one is “overdue”. Maps show dramatic movement of the North magnetic pole in recent decades; it’s headed out of Canada towards Russia. This has the potential to be very bad, and not just because we’ll lose track of which way is north when the compass needles stop working. The Earth’s magnetic field acts as a kind of lightning rod to protect the atmosphere and life from solar flares and storms. Satellites would be wrecked, animal migration patterns skewed and major climatic changes could have drastic effects on human agriculture. WHY the field is weakening is unknown – we aren’t even sure HOW the so-called geodynamo works in the first place. Recent theories/hypotheses/guesses include a five-mile-diameter ball of liquid uranium acting as a gigantic fission reactor at the core, which isn’t as nutty as it sounds considering that natural nuclear reactors have been discovered before. Hollywood’s take on all of this is coming soon to a theatre near you…