This week the team decided to use a scoop on the arm to dig up a sample of dirt and found it contained about 1 percent water ice, NASA researchers said.
Held in a scoop on the rover's mechanical arm, the tablespoon of pulverized gray rock offers planetary scientists their first sample from the planet's interior, where it may have been sheltered from the harsh surface chemistry and ultra-violet radiation.
Sample late-April interest rates were 2.65% for a five-year hybrid ARM, 2.85% for a seven-year hybrid ARM and 3.24% for a 10-year hybrid ARM, he added.