Earth Science Unit StudyWeek 6: We built our own compasses and did an activity to learn more about the Earth's magnetic field.
The Earth's magnetic field is generated by the liquid iron continuously flowing in the core. Today our compass needles point north, but it hasn't always been that way. Scientific evidence found in pottery, Hawaiian volcanic lava flows and ancient lava flows suggest the Earth's magnetic field changes direction every 200,000 years or so. Being that it's been over 700,000 years since the last reversal, we are overdue for a flip.
The magnetic field protects us from the sun and from solar weather. Without it, solar weather would bombard our planet with radiation and strip away the atmosphere as it has done to Mars. On the positive side, the gorgeous northern lights are visible reminder of the magnetic field. If the magnetic field does change directions during our lifetime, the northern lights would be visible all over the planet.
Since the interaction between the magnetic field and solar radiation is responsible for the northern lights, we couldn't resist a few extra short videos.
Playing with Magnets
Earth's Core and Magnetic Field in a Bottle
Making a Compass
This post is linked to:
We Made That