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.
There are 464 extrasolar planets, and 8 planets within our Solar System. This makes a total of 470 known planets.
230
14
About 4.5 billion.
NINE!!
There are eight planets. Pluto, formerly classed as a planet, has been reclassified and is now one of three dwarf planets.
To date (2009) no planets have been found around Ad leonis (GJ 388)
Within our solar system, there are 8 planets, and 4 dwarf planets. There are also over 500 dwarf planets from 2 galaxies that have been discovered orbiting other stars.
The only planet from our solar system that has been mentioned in the Stargate series is Earth. Other planets do not have stargates, since from the beginning the planets are not habitable.
8 planets and 5 dwarf planets, so 13 in total. There are some additional dwarf planet candidates that have not been officially categorised yet.
At least 32 have been found on October 19 2009!
42.068