Mercury is the closest to the sun and it gets to about -247 degrees to147 degrees it is grey even though it is the closest to the sun.
2 men have reached mercury.
One year is 88 days and it takes one year to orbit the sun. Mercury has a molten core.
Mercury is the most cratered planet in the solar system.
It snows in mercury only a little bit though.
Mercury is the second hottest planet in the solar system.