This occurs when a liquid outer core revolves around a solid outer core, in the opposite direction of the planet’s rotation. Such a shield could leave Mars in the relatively protected magnetotail of the magnetic field created by the object, allowing the Red Planet to slowly restore its atmosphere. Now, new simulations by NASA suggest there could be a way to naturally give Mars its thick atmosphere back – and it doesn't require nuking the Red Planet into submission, as Elon Musk once proposed. Strangeway isn't convinced.
The core activity is what maintains the protective magnetic field of Mars’ neighbor closer to the sun. For Mars to “restart” (actually regain, but we quibble) its magnetic field its core would have to become active or active at a higher level. Limits on magnetic field strength from Magellan magnetometer data are 0.000015 times Earth's field. But nevertheless the Martian magnetosphere is still capable of offering some … This, however, does not mean that Mars does not have a magnetosphere; simply that it is less extensive than that of the Earth.
It's mainly due to the fact that earths core rotates, and the core in Mars doesn't. Facts about Mars' magnetic field. In comparison, the loss rates on defenseless Venus and Mars could have gone up by a factor of a thousand or more, relative to Earth. The result is clear: Earth’s magnetic field is vital for keeping our atmosphere in place. Earth's magnetic field is generated by an active dynamo - a hot core of molten metal. The most that could happen would be that the rotation of the two planets would synchronize like gears so one would rotate clockwise, the other counterclockwise, but I think that has already happened to a point …
However, Earth's density is higher than that of Mars – 5.514 g/cm 3 compared to 3.93 g/cm 3 (or 0.71 Earths) – which indicates that Mars' core region contains more lighter elements than Earth's. In 1998, the Mars Global Surveyor detected sporadic magnetic fields around the southern hemisphere of Mars.
Scientists think Mars lost all of this when its protective magnetic field collapsed billions of years ago, and solar wind – high-energy particles projected from the Sun – has been stripping the Red Planet's atmosphere away ever since.
Taking both of these factors into account, a space-based magnetic field around Mars only needs to have a strength of roughly 11% that of Earth’s. The current scientific consensus is that, like Earth, Mars once had a magnetic field that protected its atmosphere. In the 1940s, Walter M. Elsasser proposed the model of dynamo theory , which attributes Earth's magnetic field to the motion of Earth's iron outer core . However, these magnetic fields were incredibly weak and short-lived compared to the Earth’s.
The various Martian magnetic fields do not encompass the entire planet and are local (right image). The surface of Mars is dry and dusty, with many similar geological features to Earth. Study of Earth's magnetosphere began in 1600, when William Gilbert discovered that the magnetic field on the surface of Earth resembled that on a terrella, a small, magnetized sphere.