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?

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.

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.

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.

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.

Explanation:

The passage states that the Curiosity rover found rounded, smooth pebbles in Gale Crater, which indicated flowing water once moved them, and this supports theories about past life on Mars (since water is needed for microbial life). The first option incorrectly claims the rover proved microbes existed, which the passage does not state. The second option omits the link to water and life. The fourth option incorrectly mentions human settlement, which is not discussed in the passage. The third option accurately covers the key points: the rover's images of smooth rocks suggested past flowing water, and this supports the idea that life may have existed.

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.