The moon looks whitish, but that doesn’t mean the moon is 40,000 degrees! And Mars looks red, but that doesn’t mean the surface of Mars is 3,000 degrees!

The moon looks white and Mars looks red for the same reason that a sweater looks blue. At visible wavelengths, these solid bodies reflect light from our sun. But at 70 °F Mars radiates at much longer wavelengths called infrared, where our eyes are not sensitive. The iron in Mars' dirt absorbs all the colors from the sun except red, which it reflects. Mars has a surface temperature of about 70 °F. Mars, the moon and even a sweater do produce their own light just as the sun does.