Ancient Irish Cross Slabs carved in Mars Rock caught by Mars Rover Opportunity

A remarkable symbol is carved in a rock on Mars. A photo taken by Mars Rover Opportunity shows what appears to be a Cross Slab(s) similar to a Celtic or Irish cross shape.
Link original NASA image: 
https://mars.nasa.gov/mer/gallery/all/1/m/3720/1M458433044EFFCEQKP2955M2M1.HTML​

​The Celtic cross and Irish cross shape itself has been widely used by many ancient peoples, long before the arrival of Christianity.

Its four arms were perfect for denoting the four elements, the four directions of the compass, and the four parts of man - mind, body, soul and heart.

The addition of the ring around the cross has had many explanations, everything from sun worship and symbolism, to creating a shape with the cross that was well contained and aesthetically pleasing.

An Irish legend tells how St. Patrick, a 5th-century Romano-British Christian missionary and bishop in Ireland created the first Celtic cross by drawing a circle over a Latin cross to incorporate a pagan moon goddess symbol. For an Irish Catholic, the circle in the Celtic cross may be a symbol of eternity and the endlessness of God's love. It can even represent a halo emanating from Christ.

Is an ancient extraterrestrial race responsible for the ‘cross shape with additional ring’ on Mars and they brought this symbol to planet earth as a sign of eternal life?