Figure 1 of the paper, showing Perseverance’s travels inside Jezero Crater. PIXL is an instrument on the rover. The numbers indicate the Martian days since landing. The Three Forks Depot is where Perseverance placed its first cache of sample cores. Click for original.

Scientists analyzing data taken by the Mars rover Perseverance while it traversed the floor and delta inside Jezero Crater strongly suggests that the landscape there experienced multiple past wet periods.

In Jezero, the 24 mineral species reveal the volcanic nature of Mars’ surface and its interactions with water over time. The water chemically weathers the rocks and creates salts or clay minerals, and the specific minerals that form depend on environmental conditions. The identified minerals in Jezero reveal three types of fluid interactions, each with different implications for habitability.

The first suite of minerals — including greenalite, hisingerite and ferroaluminoceladonite — indicate localized high-temperature acidic fluids that were only found in rocks on the crater floor, which are interpreted as some of the oldest rocks included in this study. The water involved in this episode is considered the least habitable for life, since research on Earth has shown high temperatures and low pH can damage biological structures.

…The second suite of minerals reflects moderate, neutral fluids that support more favorable conditions for life and were present over a larger area. Minerals like minnesotaite and clinoptilolite formed at lower temperatures and neutral pH with minnesotaite detected in both the crater floor and the upper fan region, while clinoptilolite was restricted to the crater floor.

Finally, the third category represents low-temperature, alkaline fluids and is considered quite habitable from our modern Earth perspective. Sepiolite, a common alteration mineral on Earth, formed under moderate temperatures and alkaline conditions and was found widely distributed across all units the rover has explored. The presence of sepiolite in all of these units reveals a widespread episode of liquid water creating habitable conditions in Jezero crater and infilling sediments.

You can read the peer-reviewed paper here. The uncertainty of these results is important to note. The analysis did not actually look at real samples. It took data obtained by Perseverance and used computer models and AI to analyze it. The research also assumes the minerals formed based on our understanding of such geological processes on Earth. On Mars conditions are very alien, and could result from chemistry we as yet do not understand, or are unaware even exists.