Hi Maurine - HMS Jupiter was sunk by a mine while part of an allied cruiser force during the Battle of the Java Sea on 28/2/1942. (The discrepancy in the date is probably a clerical error). Tragivally the mine had been laid only a few hours earlier by an allied ship, the Dutch minelayer Golden Leeuw.
HMS Jupiter had sunk a Japanese submarine on 17/1/1942.
Additional details on the CWGC site were usually provided by the families but not all families bothered to do so and some may not have been aware they could.
David