The core box dust cap is characterized in that a square core box cover (2) matched with the periphery of the core box is mounted on the core box (1).

岩心盒(1)上装有与岩心盒周边相吻合的方形岩心盒盖(2)。

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Impact craters surrounding the cap appear to be filled with ice and dust that was either deposited by wind or condensation, or perhaps further remains from an earlier larger ice cap.

BBC: By BBC News Online Science Editor Dr David Whitehouse