Researchers have found that liquid water is likely deep beneath Mars' surface, with reservoirs possibly located more than 7 miles underground. This discovery suggests that the Martian subsurface may hold the ingredients necessary for life, similar to microbial life deep within Earth's crust. The study highlights that the volume of water beneath Mars could exceed that of hypothesized ancient Martian oceans. While direct study of this deep water is impossible, the findings have significant implications for understanding Mars' water cycle, potential for life, and future missions.