Question

nasas curiosity rover landed on mars in august of 2012 to begin a detailed exploration of the martian surface. early in its mission, the rover collected data from gale crater that led scientists to gain insight about mars geology billions of years ago. as the curiosity rover roamed through this ancient crater, it recorded clear images of rocks the size of pebbles. these rocks were found in places and arranged in ways that indicated water must have moved the rocks some distance. the look of the rocks—rounded, smooth, and flat—suggested that flowing water shaped them. the rocks helped scientists to confirm that marss dry landscape was once quite different. furthermore, since water is a basic need for microbe life, the finding of these pebbles supports theories about the history of life on this planet. which is the best summary of the passage? the information collected by nasas curiosity rover suggests that water once flowed on the surface of mars. the rovers discoveries make scientists think human settlement on mars is possible. nasas curiosity rover found pebbles on the surface of mars in gale crater. the pebbles were smooth and rounded, and they were spread out, suggesting that they had been moved by some force. nasas curiosity rover proved in 2012 that mars once had living microbes on its surface. these microbes lived in flowing water, which created pebble deposits in river beds and the gale crater. when nasas curiosity rover sent images of smooth rocks on mars back to earth, the information suggested that water once flowed there. scientists think if water was present life may have existed as well.

Explanation:

The passage details NASA's Curiosity rover's findings on Mars in 2012. It focuses on smooth rocks in Gale Crater indicating past water flow, and how water - a key for life - suggests possible past life on Mars. The first option wrongly mentions human settlement. The second option lacks the life - related aspect. The third option wrongly claims proof of past microbes. The fourth option correctly summarizes the rock discovery, water flow indication, and life - related speculation.

Answer:

When NASA's Curiosity rover sent images of smooth rocks on Mars back to Earth, the information suggested that water once flowed there. Scientists think if water was present life may have existed as well.