Mars is probably becoming habitable already 4.2 billion years ago, i.e. well before the previously estimated in the scientific theories accepted. The revised dating replacing then the beginning of life on the red planet near the end of the so-called “Intense bombardment late” of giant asteroids that have affected the Solar System. In practice, the first micro-organisms would have developed about 500 million years before the more ancient forms of life on Earth, a sign that mars the process has occurred but sooner than expected.
Unfortunately, as you are trying to understand, it seems that the planet was a world similar to the evolution of our land before a protoplanet (perhaps coming from the asteroid belt) enter in a collision. A little has happened to the land in the battle with his nemesis Theia that gave beginning to the formation of the Moon, Mars from the crash would have had the worst losing part of its original confirmation with major disasters to the magnetism of the core and to the atmosphere.
Mars habitable already 4.2 billion years ago: Here is the latest news The international research team that has discovered the new dating of life on Mars is involved the University of Western Ontario, colleagues in the Royal Ontario Museum, the University of Portsmouth, the Johnson Space Center of NASA was coordinated by professor D.E. Moser.
The Canadian professor has analyzed the minerals more ancient found in some areas of southern Europe of the Red Planet, i.e. zircons and grains of baddeleyite subjected to electron microscopy techniques and tomography. In so doing, scientists have proved that “these minerals were not subjected to pressures and temperatures enormous as you expect from the fall continues to giant asteroids“. The evidence of this cellular activity is actively sought from the rover Curiosity of NASA, waiting that between twenty years there will be landing of men on the planet.