When you start seeing a set of objects, or more interestingly two sets, over and over, that are lined up according to a similar axis, relative to EACH OTHER, you begin to say to yourself ... hmmmm, that's very interesting. One set is perhaps a coincidence, but two distinct sets??? Here's an example of two items photographed by rover Spirit, each belonging to its own set, that similarly repeat over and over in the photographs, often in the same scene, and usually aligned to the same axis, relative to their consistent shape and one another. Does it prove they're biological? No, but it's suspicious as hell.
