Mercury is a very cool planet! The only thing not cool about the planets high temperature! 800 degrees, wow! That’s what I call hot! The cool temperature gets down to -350 degrees farenhight! Living on Mercury would be very hard! But the temperature is not the only reason… Mercury is made of rock and there are lots of craters. A whole year on Mercury is 88 days! It is 3,31 miles long! Thats alot smaller than earth!