I used the Valve Destinations Workshop Tools to visit Mars in virtual reality today. The terrain appears to have been generated using photogrammetry.
This video was captured from the left eye of my Vive head mounted display. The Destinations Workshop Tools application describes how to create your own destinations and contains other experiences to explore. If you are interested in this technology and how to create your own views of Mars you may also like my article describing how to create a 3D model of the surface of Mars.