Yes
Rock and traces of various gases, such as oxygen, nitrogen.
May be possible that in the future the Moon separated from Earth?
Two rovers of different kinds have landed on Mars. The first Mars Rover landed in 1997. The first Mars Navigator landedin 2004.
Yes, it will never leave unless humans go there and pick it up.
Mars Rover Reaches 8-Year Mark on the Red Planet
Mars Rover Curiosity Set to Launch in Two Weeks
NASA Launches Mars Rover
Mars Rover Finishes 3-Year Trip