Which of the following observations indicates that conditions on Mars may have been suitable for life in the past?
A)There are very large extinct volcanoes on Mars.
B)There is a very deep and long canyon that extends across Mars.
C)There is liquid water as well as a significant number of dried-up riverbeds on Mars.
D)Mars has polar caps made of "dry ice."
E)Mars has two small moons.

Question

Quizplus · Accepted Answer

The presence of liquid water and dried-up riverbeds on Mars suggests that there may have been a time when conditions were suitable for life to exist. Water is an essential ingredient for life as we know it, and the existence of riverbeds indicates that water once flowed on the surface of Mars.

Which of the Following Observations Indicates That Conditions on Mars