Mars is the most earthlike planet in the solar system. But that doesn’t mean that it’s very much like Earth.
Barely half of Earth’s size, Mars orbits roughly one and a half times farther from the Sun than Earth does. It is a small, cold, seemingly barren world, a frozen desert of ironrust sands from pole to pole.
Yet Mars is a spectacular world. The tallest mountain in the solar system is the aptly named Olympus Mons, a massive shield volcano three times higher than Everest, with a base as wide as the state of Idaho. The main caldera at Olympus