MPL was to have landed at Mars' South Pole on 3 December but the last that was heard from it was a routine transmission sent as it began the final phase of its descent.
Scientists think that the most likely explanation for the silence is that it tumbled into a hole.
Despite the virtually certain loss, the MPL flight team have continued their efforts to regain communications with the lander. All attempts will end on Monday, at which time MPL will be officially declared lost. Vision impossible Attempts to capture a picture of MPL's parachute from MGS have so far been unsuccessful. However, scientists have just obtained additional information from MPL's navigation data, which includes data up to the day of landing. This means that the search area for the parachute has shrunk considerably.