According to a study published in the periodical Science, Italian researchers believe they have detected a stable body of water on Mars.
The abstract of the body of the study via Science reads:
The presence of liquid water at the base of the martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015 contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections are evident within a well-defined, 20-kilometer-wide zone centered at 193°E, 81°S, which is surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has high relative dielectric permittivity (>15), matching that of water-bearing materials. We interpret this feature as a stable body of liquid water on Mars.
"It's a very promising place to look for life on Mars," planetary scientist at the National Institute of Astrophysics in Bologna, Italy Roberto Orosei said. "But we do not know for sure if it is inhabited."
The big thing here, aside from obviously water on Mars, is that they believe it to be salt water, which could potentially hold life (albeit microbial).
It's also worth mentioning that outside experts have not been able to confirm the findings with other radar detections like SHARAD, the Shallow Radar sounder onboard the Mars Reconnaissance Orbiter.
In an email obtained by CNN, Mars Reconnaissance Orbiter SHARAD deputy team leader and senior scientist at the Planetary Science Institute Nathaniel Putzig commented:
"We don't see the same reflector with SHARAD, not even when we recently summed together [thousands] of observations to create CATSCAN-like 3-D views of both polar caps. We're hoping to carry out that same imaging process with the MARSIS data next. I'm excited to see how the 3-D imaging will clarify the view of this detection and whether we will find similar ones elsewhere beneath the polar caps."
We'll let you know as soon as the findings are confirmed or refuted.