Mercury is the closest planet to the Sun and a little bigger than our Moon. It has no substantial atmosphere and looks similar to the Moon with its old, dead and cratered surface.

Messenger

Composite image of Mercury stitched together from the two year Messenger mission that began in 2011.

FOREVER

Human Eye

Mercury is always visible to the unaided eye as a bright star near the horizon just before sunset and just after sunrise. The earliest known recorded observation is from the 14th century BC.