Space Events

The Sun's Magnetic Field is about to Flip

According to measurements from NASA-supported observatories, the sun's vast magnetic field is about to flip. "It looks like we're no more than 3 to 4 months away from a complete field reversal. This change will have ripple effects throughout the solar system."

The sun's magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun's inner magnetic dynamo re-organizes itself. The coming reversal will mark the midpoint of Solar Cycle 24. Half of 'Solar Max' will be behind us, with half yet to come.

The poles are a herald of change. Just as Earth scientists watch our planet's polar regions for signs of climate change, solar physicists do the same thing for the sun. Magnetograms have been tracking the sun's polar magnetism since 1976, and they have recorded three grand reversals - with a fourth in the offing.

A reversal of the sun's magnetic field is, literally, a big event. The domain of the sun's magnetic influence (also known as the "heliosphere") extends billions of kilometres beyond Pluto. Changes to the field's polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space. The heliospheric current sheet becomes more wavy when the sun's magnetic field flips. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet.