Free Astronomy Magazine March-April 2021

47 MARCH-APRIL 2021 MARS ROVERS Mars 2020 is one more step in sup- port of the larger Mars Exploration Program that has included all of the missions featured in this issue. The Perseverance rover has four mission objectives that clearly emphasize the bio-centric focus of NASA’s cur- rent Martian interests: (1) “Looking for habitability” – in this case, the search is for data about past habitability in further support of our current models of ancient Mars as a warmer, wetter, and po- tentially life-supporting planet. (2) “Seeking biosignatures” – we “S even minutes of terror” − the descent process for Perseverance into Jezero Crater. [NASA/JPL] T he landing ellipses for several past Mars missions, centered on the planned landing region for Per- severance. Changes to lander descent technologies and guidance have greatly reduced the descent uncer- tainties and enabled increasingly tar- geted deliveries of rovers to selected locations. [NASA]