Recent observations of Mars have revealed strong evidence that water once existed in substantial amounts on Mars.Which of the following is NOT one of these observations?
A) Teardrop-shaped islands in smooth valleys
B) Outcrops of sedimentary rocks
C) Deep meandering gullies
D) A network of linear features resembling canals

Question

Quizplus · Accepted Answer

The idea of the existence of "canals" on Mars was a popular misconception in the early 20th century, but has been thoroughly debunked by modern observations. Therefore, the observation of a network of linear features resembling canals is not a valid piece of evidence for the past existence of water on Mars.

Recent Observations of Mars Have Revealed Strong Evidence That Water