Before you cry “rubbish” the pictures below have been certified genuine by NASA.
Not only that NASA has also started to suggest they “may be” unexplained or out of place objects.
The images demonstrate a small round flat disk on the ground pointed out with the yellow arrow apparently caught in a rock crevasse that is also filled with what looks like soil. If it is soil and not dithering smudge image tampering, the soil covers roughly half the disk hiding that portion from view. Note that the surface of the disk reflects sunlight a little more than the adjacent rock surfaces and more uniformly. This suggests that this object may very well be smoothed metal. Also note the uniform thickness of the disk as demonstrated by its left exposed portion casting a short shadow against the rock surface it is laying on.
Now this disk obviously looks like a metal coin and is very suggestive of that as many of us will see it. However, without the fine detail of the disk’s surface, we can’t be conclusive beyond this being just very suggestive. This inconclusive situation to a large extent is a function of the very high .jpeg compression on this imaging as released for public consumption. This object is plenty close enough to the Spirit rover panoramic camera that such details should be available to us if this imaging is as good as it was suppose to be.
It’s a real coin !
A high-power camera on the Mars Curiosity rover snapped a picture of a 1909 American penny featuring Abraham Lincoln. The coin is used as a calibration target for the Mars Hand Lens Imager (MAHLI) that is at the end of Curiosity’s robotic arm. In just over an Earth year on the Red Planet, you can see the bright copper is muted by lots of Mars dust.