Mercury

Mercury is the innermost and also the smallest planet of our Solar System. Named after the Roman messenger of the Gods for its quick movement across the sky, its proximity to the star and lack of atmosphere cause huge variations in its surface temperature - from 427 degrees Celsius on the day side to -179 degrees at night. Though Mercury currently remains one of the least explored planets of our home system, scientists expect to learn much from the MESSENGER probe which successfully entered its orbit on March 18, 2011. Learn more about the extreme and mysterious planet in this book.