Comment Re:How did it form an atmosphere? (Score 1) 98
It probably had a magnetic field in the long distant past. I am no geologist, but assume many of the same elements are on Mars as Earth; however Earth is much denser. Olympus Mons is about 14 miles high. Something was hot liquid billions of years ago, and if there were metallic ores, would have generated a magnetic field for at least a little while.