The earth is a planet, it has no known planets within.
The Whiskey tax became law in 1791
Currently there are 353 known extrasolar planets (that is to say, outside of our solar system), but it is unknown how many planets exist in the universe.
The number of planets is not known. The number of stars is not known either, nor if all have planetary systems. Certainly many billions of billions.
It is not generally known how many planets are in each galaxy; it isn't even known how many planets are in our own galaxy, and will probably never be known exactly, due to its enormous size. However, according to latest observations, it seems likely that every star has several planets, at least on average.
There are more than 300 known stars with known planets, and the list gets longer all the time.
There are 464 extrasolar planets, and 8 planets within our Solar System. This makes a total of 470 known planets.
It's easier to ask how many were known, and the answer is six.
The Egyptians along with many other cultures would have known about the six naked eye visible planets. (Mercury, Venus, Earth - obviously), Mars, Jupiter and Saturn.
There are more than 300 planets currently known to be outside our solar system.
The inner planets are known as terrestrial planets because they are rocky like earth
mercury and venus are known as light planets, because they are closest to the sun.