Mars is smaller than Earth, with a day that is 24 hours and 37 minutes and a year that is 686 Earth days. It has seasons due to its axial tilt, but its atmosphere is very thin with mainly carbon dioxide and no oxygen. Mars is also farther from the Sun than Earth and much colder, with temperatures ranging from 40 degrees Fahrenheit down to -195 degrees Fahrenheit. In contrast, Earth has a thicker atmosphere with nitrogen and oxygen, oceans and water features, and warmer temperatures from -128 to 136 degrees Fahrenheit.