Was Mars a world surrounded by water?

Did bodies of water exist on the surface of Mars in the past and did life exist there? Recent studies in the field have changed our perception on the subject

Yoram Ored, Galileo
Did bodies of water exist on the surface of Mars in the past and did life exist there? These two questions have been asked for decades and so far no unequivocal answer has been received regarding either of them. Research supported by evidence obtained using the two surface rovers on Mars - Spirit and Opportunity - suggests the possibility that the planet was once surrounded by a huge ocean that surrounded the entire surface of Mars. The study was conducted by researchers James Greenwood (Greenwood) from Wesleyan University, Connecticut, and Ruth Blake (Blake) from Yale University in Connecticut. The same evidence that led researchers to hypothesize the existence of the giant ocean also leads to the possible conclusion that life did not exist on the surface of the planet at the time of the ocean's supposed existence.
The Spirit and Opportunity spacecraft are located at two distant sites on the surface of Mars and both discovered sulfates (sulfides) formed in liquid water. This discovery points, according to the researchers, to the existence of water. The findings from both compositions also indicate the existence of phosphates (phosphorus), which also interact with water. Furthermore, the ratio between the amount of phosphorescence and the amount of sulfurization at both sites is equal. The researchers claim that since the two SUVs are located at a great distance from each other, the most likely hypothesis is that there was a huge ocean on the surface of Mars that surrounded it all.
 The existence of such an ocean allows the mixing of the materials uniformly. The phosphorescence originates, most likely, in rocks. However, the researchers admit that the phenomenon of the equal ratio between the amount of phosphates and the amount of sulfates can also be explained by wind, which mixed the materials after the drying of smaller bodies of water and spread them over the surface of the planet.
The researchers say that the fact that the phosphors melted and mixed with the water indicates that this supposed ocean was very acidic, because such a mass is only possible in acidic water. Also, according to the researchers, the fact that the ocean is rich in phosphors is a sign that does not bode well
for the possibility of the widespread existence of life on the surface of Mars. The reason is that phosphorus, found in phosphates, is an important factor for life, so it is quickly removed from the environment by the organisms that consume it.
The research only whets the appetite to send more spacecraft to Mars, in order to strengthen or disprove the hypothesis of the existence of that all-embracing ocean, and most of all... to find out if, after all, life once existed on the surface of Mars, and perhaps still exists...
And in the same matter, at the meeting of the American Astronomical Society held in the middle of January 2007, it was suggested that life may exist on the surface of Mars, but NASA simply does not know how to look for it. A comprehensive study published a few weeks ago demonstrated how the "Viking" missions would have missed bacteria on The surface of the Earth, a planet teeming with life forms, due to the problematic testing method.
In the years that have passed since the Viking study, many details have been discovered about the possibilities of sustaining life in various extreme environments on Earth. Comprehensive studies have shown that various creatures, and in particular bacteria, can exist even in situations that were previously considered impossible for life. There are bacteria that are able to exist at extremely high or low temperatures, in places where there is an extreme level of acidity or salinity, and more. Through various mechanisms, the creatures are able to exist and even thrive in these environments.