Centrifugal force is one aspect of gravity what the thing itself is no one agrees, except that the more mass a body has, the stronger the gravitational pull - Jupiter’s gravity is many time Earth’s.
Orbiting the sun has nothing to do with the strength of a body’s gravity. Mass seems to be the determinate factor.
Mars has weak gravity, and gasses escape it more rapidly than gasses in Earth’s atmosphere, however, Mars does have an atmosphere.
The recent mars/water hype from NASA centers not on the water which the media decided to focus on, but around the presumption that Mars suffered a catastrophic event which blew the atmosphere off. Some obvious evidence for some sort of catastrophe is a comparison of one hemisphere with the other - both are very different - one has many craters, the other only a few. in fact the hemisphere with many craters looks like it was hit by cosmic shotgun pellets. There are also a number of non-mainstream theories on how this might have occurred.
The reason the media neglect to mention the actual message NASA revealed is just that the very idea contradicts the steady state historical model the media favors - also admitting that major historical catastrophes actually happened could cause the same panic in people’s minds that the very thought of Republicans winning the Presidency, House and Senate produces in the media’s collective minds.
A property of mass is the distortion of space. Mass-free theoretical straight line paths in space are in fact altered to curved pathways by the presence of any mass, as evidenced by observation. A local observer (orbiting body) notes no applied acceleration affecting the course of the body. Warped space around a massive body allows another body to move without external imposed accelerations, yet follow a closed path.
Curvature of space is greater for a given mass, as distance to a mass is diminished. Static gravity is an effect of differential curvature of space, as a function of distance from the center of a mass. More mass= more space curvature= more observed gravity.
The lack of a magnetosphere, for lack of a strong magnetic field, allows the plasma from the solar wind to interact with the Mars atmosphere. Energy added sufficient to achieve orbital escape velocity of high altitude atoms or molecules from the Martian atmosphere, is the primary driver of depletion.