Mercury

• Mercury is the smallest planet in the solar system, even smaller than some moons.
• Not only is Mercury the smallest planet, it is also shrinking.
• It is the closest planet to the Sun and orbits around it in just 88 Earth days.
• Mercury has a very thin atmosphere, and its surface is heavily cratered and looks like the Moon.
• It has no moons or rings, unlike other planets in the solar system.
• Mercury has the highest density of any planet, which means it has a large iron core and a relatively thin mantle and crust.
• Because of its proximity to the Sun, Mercury experiences extreme temperature variations, ranging from -173°C to 427°C (-280°F to 800°F).
• Mercury has been visited by only two spacecraft, Mariner 10 in 1974-75 and Messenger in 2008-15.
• Mercury's year is only 88 Earth days long, but its day is 59 Earth days long, which means it rotates very slowly.
• Mercury is one of the five planets visible to the naked eye from Earth, and it can be seen just before sunrise or just after sunset.