In case you didn't know red planet refers to the fourth planet in the Solar System, Mars. (Hey, if you were unaware of that information it is okay. I can't even begin to tell you how long it took me to figure out that Third Rock From The Sun was referring to the third planet, Earth.) This day is in dedication to the Mariner 4 (a space probe used for photographing planets)  reaching Mars back in 1964.

Fun fact: Mars gets it's name from the Roman god of war, Mars. If you want to celebrate this holiday in any way, at the very least you can go out and research Mars (the planet, not the Roman god). Try using a telescope and try find Mars in the night sky. If you want to learn more about today's holiday and more fun facts, click here.