Landing the penny on Mars and using it as a gauging target was not specific enough??? Of all the events associated with that landing, how do you get just the soil sampling from the presence of the penny???
The Hawaii taste was specifically not a clue.
The Forbes article has all the numbers you need.
More clues if anybody wants them, just don't want to drag this out.
Verum audaces non gerunt indusia alba. - Ipsi dixit MCMLXXII