Ever since July 1, 1867.
The Moon and Earth
no, because the moon isn't a planet, and earth is the only one.
Yes mariner 3 has been to the planet Saturn
Scientists do not believe that any planet ever crashed into Venus.
No highly civilised planet has ever been discovered to date. Including the one you are stood on.
Mars where no human has ever been.
No human has ever been to another planet except the moon. These days the moon is not considered a planet but it was in ancient times. No human has ever been to Earth because that implies you're back from travel. We are all here already.
As for as is known no earthlings have ever been on Mars.
No scientists from Earth have ever been to Mars.
How should you answer “What's on your mind?”?
Saturn is a gas planet, so it has no surface