Mars has no global magnetic field like the Earth does. However, magnetic measurements of the surface of Mars indicate that there is a localized magnetic field, trapped in the surface rocks in the southern hemisphere (see first image below). The second image, shows these same locations but with impact craters more clearly seen. (NOTE: the two images are shifted from each other. The region of strong magnetic field in image \#1 is at the edges of \#2, as shown by the location of the arrows) What do these two images suggest about Mars and its magnetic field? The strongest magnetic field on the surface of Mars is in the south, where the crater density is the highest. The northern areas that have no magnetic fields are where the the crater density is the lowest. This suggests that the meteorites that caused the cratering where magnetized. When they hit the surface they kept their magnetic fields. Since more impacts happened in the south, there is much more magnetism there. In the north fewer magnetized meteors hit the surface, and therefore the magnetic field is weaker. The relation between the strength of the surface magnetic field and the crater density is obvious. If we assume that the crater density tells us the relative age of the surface, then clearly the southern hemisphere is older than the northern hemisphere. It is also the case that the northern hemisphere has most of the large volcanoes which probably spread lava everywhere in the north. This lava must have not contained iron, since iron is magnetic and there is no magnetic field in the north. This suggests that Mars has no iron and is only composed or light elements like silicon, calcium and lots of water. Since the core of Mars must only be made of water, it cannot create a global magnetic fieid. the core of Mars must only be made of water, it cannot create a global magnetic field. The strongest magnetic field is in located in the southern hemisphere. This is also where the crater density is the highest. This suggests that Mars never had a global magnetic field like the Earth. Instead it was only concentrated in the southern hemisphere. This strong magnetic field pulled in iron meteorites (which are attracted to a magnet) and crashed them into the southern hemisphere. Since the northern hemisphere never had a magnetic field, it did not attract meteors to the north. This means that the two hemispheres of Mars have the same surface age but the difference in crater density is due to the southern magnetic field. This field prevented the meteors from hitting the surface randomly like we see on other planets and moons. The strongest magnetic field is in the southern hemisphere of Mars. This same area also has every high impact crater density. The areas that have no magnetic field in the rocks are areas where the crater density is much lower. This means the surface with a strong magnetic field is located where the crust is very old. Magnetic fields are locked in rocks when they become a soli.

1. Mars has no global magnetic field like the Earth does. However, magnetic measurements of the
surface of Mars indicate that there is a localized magnetic field, trapped in the surface rocks in
the southern hemisphere (see first image below). The second image, shows these same locations
but with impact craters more clearly seen. (NOTE: the two images are shifted from each other.
The region of strong magnetic field in image #1 is at the edges of #2, as shown by the location
of the arrows) What do these two images suggest about Mars and its magnetic field? The
strongest magnetic field on the surface of Mars is in the south, where the crater density is the
highest. The northern areas that have no magnetic fields are where the the crater density is the
lowest. This suggests that the meteorites that caused the cratering where magnetized. When they
hit the surface they kept their magnetic fields. Since more impacts happened in the south, there is
much more magnetism there. In the north fewer magnetized meteors hit the surface, and
therefore the magnetic field is weaker. The relation between the strength of the surface magnetic
field and the crater density is obvious. If we assume that the crater density tells us the relative
age of the surface, then clearly the southern hemisphere is older than the northern hemisphere. It
is also the case that the northern hemisphere has most of the large volcanoes which probably
spread lava everywhere in the north. This lava must have not contained iron, since iron is
magnetic and there is no magnetic field in the north. This suggests that Mars has no iron and is
only composed or light elements like silicon, calcium and lots of water. Since the core of Mars
must only be made of water, it cannot create a global magnetic fieid. the core of Mars must only
be made of water, it cannot create a global magnetic field. The strongest magnetic field is in
located in the southern hemisphere. This is also where the crater density is the highest. This
suggests that Mars never had a global magnetic field like the Earth. Instead it was only
concentrated in the southern hemisphere. This strong magnetic field pulled in iron meteorites
(which are attracted to a magnet) and crashed them into the southern hemisphere. Since the
northern hemisphere never had a magnetic field, it did not attract meteors to the north. This
means that the two hemispheres of Mars have the same surface age but the difference in crater
density is due to the southern magnetic field. This field prevented the meteors from hitting the
surface randomly like we see on other planets and moons. The strongest magnetic field is in the
southern hemisphere of Mars. This same area also has every high impact crater density. The
areas that have no magnetic field in the rocks are areas where the crater density is much lower.
This means the surface with a strong magnetic field is located where the crust is very old.
Magnetic fields are locked in rocks when they become a solid. This suggests that in the distant
past, when the old crust was molten, Mars had a global magnetic field. The iron in the rocks
aligned with the global field and solidified, locking magnetic field in place. This global field
disappeared before the surface in the north had formed.