Mars Exploration Rover 25, 2011, bringing the elapsed mission time to 6 years 2 months 19 days, or over 25 times the original planned mission duration. In recognition of the vast amount of scientific information amassed by both rovers, two asteroids have been named in their honor: 37452 Spirit and 39382 Opportunity. The mission is managed for NASA by the Jet Propulsion Laboratory, which designed, built, and is operating the rovers. On January 24, 2014, NASA reported that current studies by the remaining rover "Opportunity" as well as by the newer Mars Science Laboratory rover "Curiosity" will now be searching for evidence of
Sol (day on Mars) Mars Sol Date is defined mathematically as MSD = (Julian Date using International Atomic Time - 2451549.5 + "k")/1.02749125 + 44796.0, where "k" is a small correction of approximately 0.00014 d (or 12 s) due to uncertainty in the exact geographical position of the prime meridian at Airy-0 crater. The word "yestersol" was coined by the NASA Mars operations team early during the MER mission to refer to the previous sol (the Mars version of "yesterday"), and came into fairly wide use within that organization during the Mars Exploration Rover Mission of 2003. It was eventually picked up and used