One tiny planet speeds around the Sun so closely and quickly that its year is only 88 days long. That’s why it’s Merky’s favorite planet: Mercury! 

Merky likes to finish things up quickly, too. He’s much too wise to dawdle or fuss around. Because Mercury is so close to the Sun, one side is very, very hot, while the other side is very, very cold—and Merky likes to run hot and cold, too! 

“The Little Professor,” as the other Cosmic Cubs call him, might seem stern at times, but he really wants to make sure that every job is completed on time. Take it easy, Merky!