No spacecraft has visited all the planets.
voyager 2
All of the eight planets have been visited or orbited by space probes.
venus was the first planet visited by the American spacecraft
Depends on whether you say Pluto is a planet or not. If you say it isn't, then there are no planets that haven't been visited by a spacecraft. If you say it is, then there is one that hasn't been visited yet, but one is on the way.
Pluto has yet to be visited by a spacecraft because it is so far away.
It's the closet and rather similar to the earth.
I think that they have tried but failed. But i could be wrong...
Voyager 2, which flew by the giant planet in 1989.
Yes. A spacecraft has visited this planet. They came in peace. The space creatures discovered that humans fought wars with each other. As a result they wanted nothing to do with such wild animals so they left and went to a more civilized world.
Voyager 2 flew by Neptune in 1989, coming within 30,000km of the planet.
yes, spacecraft have visited Mars, but the results haven't always been positive. More than half of the attempts to send a spacecraft to the planet have failed.
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.