Exploring Mars is About More Than Martians

NASA’s Perseverance rover lands on Mars today with the goal of searching for signs of ancient life on the Red Planet. But exploring Mars is important beyond just the search for alien life.

Artist’s impression of the Perseverance rover landing beneath its skycrane on Mars. Credit: NASA/JPL-Caltech

Humans have had a longstanding obsession with Mars: Our sometimes-nearest neighbour, a world that is Earthlike enough that we can relate to its towering volcanoes and windswept dunes, yet alien enough to spark fascination about its history. The question of whether Mars ever harboured life has been the main driver behind NASA’s entire Mars Exploration Program—and for good reason. Figuring out whether or not we are alone in the universe is one of the most existential questions humanity can pose.

Discovering past or present life on Mars would be a massive discovery. But even if we don’t find evidence of life there, the absence of life is an equally important discovery.

Thanks to the armada of missions humans have sent to Mars over the past 50+ years, we know that the Red Planet was once quite Earthlike. Its surface was dotted with crater lakes, rivers, and potentially a massive ocean. Rain and glaciers shaped the surface. The atmosphere was much thicker, leading to warmer surface temperatures than what we see today.

And perhaps most importantly, Mars had these Earthlike conditions at the same time that early…