This is not correct. I believe there have been eight successful Mars landings: Viking 1 and 2, Mars Pathfinder, the two Mars Exploration Rovers (Spirit and Oppo

This is not correct. I believe there have been eight successful Mars landings: Viking 1 and 2, Mars Pathfinder, the two Mars Exploration Rovers (Spirit and Opportunity), Phoenix, the Mars Science Laboratory (Curiosity), and now this one (InSight). Failures include (going off of a list on Wikipedia) 2MV-3 (Soviet probe that never left Earth orbit; not sure if you want to count this or not since it didn’t fail during landing), Mars 2, Mars 3 (landed successfully but failed within minutes), Mars 6, Mars 7, Mars Polar Lander, Beagle 2 (landed but solar panels failed to deploy), and Schiaparelli. So I think there have been eight successes and eight failures, if you only count probes intended to land. Notably, all eight successful landers so far have been launched by the United States.