Why is Mars cold at times and hot at other times? — Travis of Pagosa Springs, CO

Dear Travis,

I like to study the solar system, too. I am fascinated by the new things we learn about the different planets. I remember the pictures that the Viking I space probe sent back to Earth from Mars in 1976. That was really neat!

Mars is never what we would call "hot." It is too far from the Sun. You probably know that Earth is 93 million miles from the Sun. Mars is about 142 million miles from the Sun (on average). In the winter, Mars can get as cold as 191 degrees below zero. In the summer, the temperature on Mars only reaches about 24 degrees below zero. So, although summer is much warmer than winter, it is never as warm as Earth. The difference in temperature is due to the fact that Mars is tilted on its axis. Just like the Earth, as Mars orbits the Sun, the seasons change. But, all the seasons on Mars are cold!