Mars, Voted Most Likely: A Grand Tour of the Solar System

Mars is the most explored planet in our solar system besides Earth, and for good reason. Although its surface is cold and inhospitable, evidence from nearly 50 years of robotic exploration suggests that Mars was once much more Earth-like. Katie Stack Morgan, the deputy project scientist on the Perseverance rover mission and a mission scientist on the Curiosity rover mission, explains why Mars remains the best place in the solar system to look for signs of ancient life.