> The penny affixed to Curiosity cost the engineer who worked on the calibration target about $5. He bought it with his own money. He chose the 1909 penny becau

> The penny affixed to Curiosity cost the engineer who worked on the calibration target about $5. He bought it with his own money. He chose the 1909 penny because it was the first year of the Lincoln-head penny. Calling it rare in the title is a bit of an overstatement, then, as this isn't the rare 1909 "S" VDB from the San Fransisco mint but the far more common 1909 VDB cent from Philadelphia.