Question

how do scientists know that there used to be water on the surface of mars? hint: select two (2) answer choices select all answers that apply a the rovers have discovered deposits of liquid water on the surface of mars. b geological features show patterns that refer to places on earth that have water. c the rovers on mars have found rock samples that show there used to be water. d the polar ice caps are made of water, which means that there must have been water on the surface of mars at some point.

Explanation:

• Option A is incorrect as currently, there is no discovery of liquid - water deposits on the surface of Mars.
• Option B is correct because geological features like river - like channels and sedimentary rock patterns on Mars are similar to those on Earth formed by water.
• Option C is correct as rock samples analyzed by Mars rovers have chemical signatures indicating past water presence.
• Option D is incorrect as the polar ice - caps being made of water does not directly prove past surface water presence in a conclusive way.

Answer:

B. Geological features show patterns that refer to places on Earth that have water.
C. The rovers on Mars have found rock samples that show there used to be water.