response: The sunset is red because of Rayleigh scattering. And the Grand Canyon is red because, ultimately, of iron oxide.
original_response: Awesome, I wonder what it will be like if there was no red in the rainbow or there is no red sky at sunset :)
history: I like red color Oh, OK. Were you aware that Mars is red because of iron oxide? I am not too sure of that but I would say I love red cars and roses Good to know. On another note, there is a metal that's in the first transition series. Uh, OK. I like red Toyota Camry sports versions. What other red things do you know about?
knowledge: The red sky at sunset results from Rayleigh scattering, while the red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide.