* No humans have ever set foot on another planet. While we've sent probes and rovers to explore Mars, Venus, and other celestial bodies, humans have only traveled to the Moon.
* Many robotic spacecraft have explored planets. These spacecraft carry instruments that gather data and send it back to Earth, giving us a wealth of information about planets and other objects in our solar system.
So, while no humans have physically explored other planets, we have learned a great deal about them through the work of robotic explorers.
