Life on Mars.. where did it go?
If there ever was life on Mars, it was probably only bacterial or microbial in nature. No complex, higher life forms. I don’t think it would have had time to develop into more complex life forms. For the reason why I don’t think there would have been time, see below. As for where everything went – Earth has a magnetic field generated by its molten, spinning core. The magnetic field protects Earth from the harmful cosmic radiation. The cosmic radiation is harmful to life, and also can strip away air and open water (albeit, very, very slowly) from the surface of an unprotected planet. Since Mars is much smaller than the Earth, it’s core cooled much faster than Earth’s and became cold and solid hundreds of millions or even billions of years ago, and any magnetic field Mars had for protection disappeared. The cosmic radiation has had those hundreds of millions or even billions of years to slowly strip away Mars’ atmosphere and open water so that, by now, Mars’ atmosphere is extremely thin
