Titan , ORGANIZATION@1 's largest and the ORGANIZATION@2 's second largest moon -LRB- after LOCATION@1 's LOCATION@2 -RRB- , is larger than the planet Mercury and is the only moon in the ORGANIZATION@2 to possess a significant atmosphere .

Saturn is a planet in the Solar System . Saturn is the second largest planet in the ORGANIZATION@2 ; the largest is LOCATION@1 . The largest moon is Titan , which is larger than the planet Mercury . Titan is the largest moon , larger than the planet Mercury , and it is the only moon in the ORGANIZATION@2 to have a thick , dense atmosphere .
