InSight is not a first. It’s the eighth successful landing on Mars since 1976, when Viking 1 became the first spacecraft to land and work on the planet, and the 45th exploratory mission of any kind since 1960. Currently, the NASA rover Curiosity is on Mars rolling around on its six aluminum wheels searching for evidence of once-upon-a-time life; another, Opportunity, went into hibernation during a dust storm in June and may never awaken.

But each mission is different, facing different dangers and different challenges. InSight’s landing alone was an extraordinary feat, as the craft had to slow down from 12,300 miles per hour to about 5 m.p.h. at a precise 12 degree angle, all within what scientists and engineers have dubbed “seven minutes of terror,” to land on the Elysium Planitia. The landing was monitored by two mini-spacecraft, each about the size of a briefcase, whose flight was a cosmic first of its own.

Unlike the mobile landers, InSight — Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — is meant to stay in one spot and deploy instruments to measure marsquakes (yes, on Earth they’re “earthquakes”) in order to learn about what’s going on in the innards of the planet. One gizmo will take Mars’s temperature by hammering itself 16 feet below the surface. Deploying the instruments alone is expected to take two months, and the entire mission is meant to last a Martian year, roughly two Earth years.

What for? A random sampling of comments from the public suggests not everyone is convinced that digging on Mars is money well spent. But the basic answer is that whether it’s practical or not, humans will continue to explore the heavens so long as the moon, Mars and the myriad celestial bodies beyond fire our imagination and curiosity. What happened in the earliest days of the universe? How were Earth and its fellow planets formed? And the question of questions: Is there life out there?

Mars may not have all the answers, but for now it’s the most accessible other planet for detailed studies. And unlike on Earth, on Mars surface evidence of how our solar system was formed has not been totally eroded away. And life! Earlier rovers found evidence of water; NASA’s coming Mars 2020 mission will have even finer tools to search for ancient biology. And after that, an earthling may actually put a footprint into the red dust.