The evolution of life outside Earth is one of the central themes in science. (Hyper)thermophiles are considered strong candidates for early life, resulting in research focus on their habitats. Thus, hydrothermal systems have long been proposed as an environment for early life. These systems are known to develop in impact craters on rocky planets, indicating that impact-generated hydrothermal systems (IGHs) have a strong potential for supporting life outside Earth. The discovery of hydrothermally produced minerals on Mars has greatly increased the potential for life and provides a new impetus for research into IGHs on this planet. We aim to provide new quantitative constraints on the development and longevity of hydrothermal systems on Mars by integrated field, laboratory, and computational studies of the unique Vargeão and Vista Alegre impact structures in Brazil. These are the only two well-exposed, complex impact structures on Earth located in basaltic target terrain, making them direct terrestrial analogues for Martian impact craters. Hydrothermally formed mineral assemblages will be determined from systematically collected samples from both structures. Through thermodynamic modelling, these assemblages provide temperature constraints, which will be combined with fluid-flow modelling to reconstruct the development of the IGHs. The models will then be adapted to Martian crustal conditions to assess the possibility of thermophiles surviving within IGHs on Mars. Expected mineral assemblages will be verified by comparison with assemblages as interpreted from remote sensing data, with the final aim to prioritise future landing sites and maximize the chance of discovering signatures of life on Mars.