Because that is the name given to the 5th planet in order, counting out from the Sun.
The fifth planet from the Sun is Jupiter.
Jupiter is the fifth planet from the Sun.Jupiter
It is the fifth planet.
Jupiter. The asteroid belt is not a planet now, regardless of whether or not it once was.
Jupiter, of course!
Jupiter is the fifth planet from the Sun counting outwards. Starting at the outside and counting in (which I think is what you were asking), Mars is the fifth planet, though if we discover a planet beyond Neptune then Jupiter would be the fifth planet counting inward as well.
Jupiter
Jupiter is the fifth planet from the sun in our solar system.
The fifth planet from the Sun is Jupiter.
The fifth planet from the sun is Jupiter.
It is the fifth planet from the sun.
Jupiterthe fifth planet is jupiter