The Viking space probes visited the planet Mars
voyager 2 is the answer and it is so fuqqin boring doing 2hunid questions in 1 day of science in 6th grade brah
space probes have crossed Pluto's orbit, but never have visited the planet because Pluto was not in alignment with the flight path of the space probes.
All of the eight planets have been visited or orbited by space probes.
All but Pluto, which is currently being visited.
April 2008 At present the only planet in our solar system that has not been visited (either by an orbiting spacecraft or flyby spacecraft) has been the recently planet downgraded body of Pluto. There is a mission currently in motion to visit this distant outpost.
No space probes have visited earth as all space probes have originated on earth and therefore cannot 'visit' because earth is it's home.
The Viking program sent two space probes to the planet Mars in 1976. It was a very expensive mission, costing approximately 1 billion dollars.
The Viking Space Probe was actually two different probes. Viking 1 and Viking 2 were used to explore Mars. The probes took photographs, did experiments and deployed instruments to the surface of Mars.
Humans have visited NO planet outside of Earth. Humans have visited the Moon, which is not normally considered a planet.Unmanned probes sent by humans, on the other hand, have already visited several planets.
viking 1
space probes
The Viking Program, which created Viking 1 and Viking 2 space probes, was invented and launched by the United States.
Curiosity opportunity and spirit