Teacher:Given a scientific passage and an answer, generate a question for the given answer.
Teacher: Now, understand the problem? Solve this instance: Passage: Viewed from Earth, Mars is red. This is due to large amounts of iron in the soil. The ancient Greeks and Romans named the planet Mars after the god of war. The planet's red color reminded them of blood. Mars has only a very thin atmosphere, made up mostly of carbon dioxide. Answer: iron
Student:
What is in the soil that causes mars to look red?