NASA has explored the surface of Mars since 1976, when the Viking 1 and 2 landers arrived and scratched the surface to teach us more about the Red Planet. Since then a steady parade of landers, rovers, and even a tiny helicopter have crisscrossed the planet, recording marsquakes, listening to dust devils, watching clouds, and investigating its rocks and soil for clues about how and why Mars was once warmer and wetter. The Perseverance rover, during its trek, even revealed a rock with potential biosignatures — traces possibly left behind by ancient microbial life.
