Free Astronomy Magazine January-February 2020

42 JANUARY-FEBRUARY 2020 ASTRONAUTICS the Spirit and Opportu- nity rovers. Subsequently, other protagonists were added: Curiosity, MAVEN and InSight. All of these missions have revolution- ized our knowledge of the red planet, and they have shown us a much more dynamic and fasci- nating world than previ- ously believed. The goals of the Mars Ex- plorer Program are es- sentially four. The first goal is to understand if Mars ever hosted life and, if it did, to verify if life is still present there. The fact that, in the first billion years of the Solar System, Earth and Mars were much more similar to one another than they are today does au- thorize moderate optimism. However, none of the Mars missions so far carried out have had technology suitable to give a definitive answer to this issue, and therefore the first goal has yet to be achieved. At least partially already achieved are the second goal, which concerns the under- standing of the history and processes of the Martian climate, and the third goal, which aims to understand the origin and evolution of the planet as a geological system. The fourth and final goal is to set the conditions T he Mars 2020 rover during the final setup and in the Mar- tian environment simulator. [NASA/ JPL-Caltech]