https://techcrunch.com/2018/07/25/there-is-liquid-water-on-mars/

After years of observation and analysis, researchers announced today that they have identified liquid water on Mars — a ton of it. It’s a mile underground and is likely only liquid because it is briny and under great pressure, but nevertheless, this groundbreaking discovery could change both our understanding of the Red Planet and our plans to one day go there ourselves.

The discovery was made by Italian researchers from a variety of institutions, led by Roberto Orosei at the Istituto Nazionale di Astrofisica in Bologna; the paper describing their work detecting and characterizing the water was published today in the journal Science.