Learn about Mars' defunct magnetic field, which may have sustained life on the planet and covered only its southern hemisphere over 4 billion years ago.
Although the magnetic field of Mars hasn't been in effect for billions of years, the evidence it left behind may suggest that the planet's core is entirely liquid. Magnetic imprints still exist on Mars, but they're centered around its southern half, raising a mystery that has left scientists scratching their heads for years. Recent research, however, has proposed a promising answer: the molten Martian core likely generated a magnetic field that only covered the Red Planet's southern hemisphere. A new study published in the journal Geophysical Research Letters offers an overhauled perspective on Mars' magnetic field, which dissipated around 4 billion years ago. This theory shows how Mars, despite sharing a few similarities with Earth, has a much different history full of unexpected surprises. How Did Mars Lose Its Magnetic Field? The history of magnetism on Mars remains a critical field of study since it is closely tied to the planet's potential capacity for life billions of years ago. Mars' magnetic field was once generated by its dynamo, a mechanism shaped by currents within the planet's liquid core (thought to be made of iron, sulfur, and hydrogen). The magnetic field would have protected Mars from space radiation and solar wind, just like Earth's magnetic field does for our planet today. But why did Mars lose its magnetic field while Earth still has one? It may have something to do with the Martian core cooling down, causing its dynamo…