M ercury is the closest planet to the sun and the second smallest in our solar system. It is actually smaller in size than Saturn's moon Titan and Jupiter's moon Ganymede, but it is greater in mass to both. Mercury was named after the Roman god of travel, commerce, and thievery. Whose counterpart is the Greek god Hermes, the messenger of the gods. It was named this because it appears to move very quickly through the night sky.
uring different seasons of the year, Mercury can be seen at different times. For this reason Mercury was given two other names by the Greeks. Apollo for when it is more visible in the morning and Hermes when it is seen at night. The Greeks knew that these two bodies were in fact the same planet.