Mars has been a popular source of intrigue over the past ten years. Thoughts of colonizing, or at the very least visiting, the red planet have been all over the news. However, one major hurdle to overcome is the martian magnetic field. Unlike other planets such as Earth, Mars does not have single-source magnetic field, but rather, it pulls from many smaller sources to generate a much weaker atmosphere. However, just because it doesn’t have a robust magnetic field doesn’t mean Mars lacks magnetism altogether. Mars possesses an ionosphere—a layer of the atmosphere inhabited by charged particles that produce electricity—that is similar to Earth’s. For Mars, it is particularly strong around its north and south pole. In order for this to exist, the planet needs to generate some form of magnetism. But where does this magnetic activity come from? Let’s turn back the pages of history to find out. Mars of Yesteryear Mars is a relatively new planet and research suggests that Mars once looked a lot more like Earth. It had rotating planet core capable of generating a magnetic field like the one we’re accustomed to. In turn, this magnetic field produced an atmosphere, leading astrophysicists to hypothesize that Mars was once much hotter, wetter, and perhaps even capable of sustaining life. But that’s all over now. Mars’ core has since stopped and the strong magnetism it once emitted is all but gone. So again, where is the magnetism coming from? Magnetic Martian Pockets Since its core came to a grinding halt, Mars has had to rely on other methods of generating its own magnetic field. For the most part, this includes pockets of magnetism strewn about its outer crust. These are deposits of strong magnetism left over from the planet’s past are much strong than similar deposits found on Earth. Unfortunately, little is known about their composition and how exactly they affect Mars’ ionosphere. One theory comes from the planet’s composition. Mars is called the red planet for a rather obvious reason—it’s red. This coloration comes from rusted metals on the planet’s surface. The most abundant of which is iron. Iron is ferromagnetic and strongly attracted to magnets. This is only one theory about what causes Mars’ magnetism. What It Means for Us Because Mars relies on these magnetic pockets, its magnetic field is a bit unpredictable and hard to plan around. One challenge is the way it interacts with radio signals. On the side facing the sun, Mars’ ionosphere is much stronger, thus satellites are only able to take measurements on the planet’s surface. Conversely, the side facing away from the sun has a much weaker field, so probes are able to go much deeper into Mars’ inner layers. Mars is only one of several planets we’ve discussed in terms of magnetism. Recently, we’ve looked at the sun, Jupiter, Saturn, Earth, and even Proxima B. If we’ve learned anything, it’s that every celestial body presents its own challenges and unique opportunities for understanding. We’ll be sure keep you posted on any and all magnetic developments!