- Scientists detected a strange ripple through Earth’s magnetic field without any obvious source.
- The wave was detected by scientists around the world, and it wasn’t linked to solar activity or anything the Sun may have sent out way.
- The particularly quiet nature of the Sun right now as it dives deep into a period of solar minimum with very little activity is allowing subtle changes in the Sun’s magnetic field to be seen and studied.
We never see it, but the Earth’s magnetic field is one of the things that allow life to thrive on our planet. It protects us from some of the harsher aspects of orbiting a star like our Sun, and researchers are constantly monitoring its status and doing their best to understand what affects it.
So, when a wave rippled through Earth’s magnetic field, researchers initially suspected the Sun had fired off something in our direction. They checked the solar wind — the name given to the constant outflow of particles from the Sun — since variations can cause similar ripples, but nothing was out of the ordinary. In this case, it seems the Sun is so quiet that scientists can “hear” things they wouldn’t normally hear.
The Sun goes through distinct cycles. During periods of high activity, our star spits out charged particles in great quantities. Solar storms, which are particularly large blasts of such particles, can affect communications grids here on Earth and mess with satellites and other spacecraft. Right now, however, the Sun is in a period of extremely low activity, and that might actually be the reason why researchers were able to detect this new ripple.
The type of ripple that was spotted is known as a pulsation continuous, (PC for short). These kinds of waves have been observed in the past, but they’re usually very difficult to spot due to activity from the Sun interacting with Earth’s magnetic field and creating a lot of noise. The ripples simply get lost in all that activity.
When external forces are so low, ripples that occur naturally are more easily visible. This particular wave is thought to be related to particles being shed by Earth’s own halo of charged particles that are shaped by the magnetic field. When the particles break loose, they can create small disturbances in the magnetic field which would never be detected during a period of high solar activity.
Scientists already know that the Sun’s solar minimum is going to be particularly quiet this time around, meaning that detecting subtle changes in Earth’s magnetic field may be easier than ever. It’s incredibly fortuitous for researchers that focus on the inner workings of our planet, and it could yield new understandings of how Earth’s magnetic field works and what kinds of things scientists miss during periods of high Sun activity.