Mars is a terrestrial planet that presents several similarities with Earth. It is a primary object of scientific study in the field of comparative planetology ; science which aims to explain the characteristics of the planets and elucidate the mechanisms of their evolution. Mars will bring a lot of answers about the evolution of our own planet and the formation of our solar system.

Mars is a planet whose exploration would permit us to understand the differences existing between the process of formation of planets and their evolution. Indeed, Mars presents a surface that has remained unchanged throughout its history, unlike the Earth which is in perpetual "renovation" (the former soil is continuously destroyed by the effects of tectonic movements and the various types of erosion, leaving room for new soil). The current lack of tectonic on the surface of Mars allows us to follow the cycles of transformation undergone by the planet during its evolution.

Because of its much smaller size and mass, Mars could have evolved much faster. The Earth, more massive, has in principle a slower cooling, while it also depend on the surface lithospheric layer and its thickness. The distance of the planet relative to the Sun is another crucial element. It influences its internal composition, explains insolation and consequently its atmosphere and its thermal history. Although comparable, chemical compositions and densities of the Earth and Mars are not identical. In spite of similar evolutions, we find that the two terrestrial planets may have known different fates. For example, it is for the moment impossible to determine if Mars has a liquid core and a solid seed as the Earth does. Can we believe that Mars reflects the future of the Earth, in the long term, when all its heat will be lost? This is, among other questions, one point that we want to enlighten by studying the interior of the planet Mars.

Men have also studied the possibility of extraterrestrial life on the planet Mars. Just like Earth, Mars is a planet that could have presented, at some point of its evolution, the conditions for the emergence of a possible form of life. The presence of liquid water on the surface or in the basement is a prerequisite for the emergence of life. Observations show that the surface of Mars is characterized by numerous traces of runoff and gullies. Scientists are not unanimous in their interpretations, but most of them believe that Mars could have a vast network of rivers, or even a large ocean, through which a form of primitive life could have developed.

Mars has always been a scientific priority, and the history of its study shows that the discoveries and exploration missions have always generated a lot of interest among the public. Mars has always cultivated our imaginations and our curiosity.

Thanks to sophisticated equipment and techniques, many questions on the red planet have been answered, improving the whole scientific exploration of Mars as a result. Today, we know that the conditions do not sustain water in liquid form on the surface, no life as we know is therefore possible on this planet.

Mars has also been studied in many other scientific fields :

• The presence of water
• Climate
• Geodesy
• Geodesy
• Magnetism

However, in all these areas, we still have many questions waiting to be elucidated. Hence the importance of missions as LaRa, MaRS, and the scientific objectives related to.