Spirit and Opportunity - Probe Sisters

Subscribe – http://goo.gl/wpc2Q1 Two previous missions to Mars had failed, but in January 2004 two robotic geologists named Spirit and Opportunity landed on opposite sides of the red planet. These robot explorers trekked for miles across the Martian surface, conducting field geology and making atmospheric observations. The rovers were designed and built in from scratch in just 3 years, and far outlived their planned mission duration of 90 Martian solar days. Carrying identical, sophisticated sets of science instruments, they found evidence of ancient environments where intermittently wet and habitable conditions existed.