1) NASA saw the first evidence of water. The rover's camera captured evidence of a stream that once ran across the north rim of Gale Crater and the base of Mount Sharp.
2) Curiosity gathered samples from rocks in the "Glenelg" area. Using its built-in chemical and mineral analysis tools, the rover found carbon, hydrogen, oxygen, phosphorus and sulfur -- which are all key ingredients necessary for life.
3) On the way to Mars, Curiousity's radiation assessment detector took measurements during the flight. It identified levels that exceed NASA's limit for astronauts. Curiosity continues to take measurements on Mars to determine potential hazards for deep space explorers.
To learn more about Curiosity, please visit: http://www.nasa.gov/mission_pages/msl/index.html