Jupiter
You are on it. It is earth.
The Earth.
Olympus Mons on the planet Mars is the largest known volcano in the Solar System.
No, no and no.
The largest planet in the solar system is Jupiter. Jupiter also has the largest moon in the solar system, Ganymede.
Jupiter, Saturn, Uranus and Neptune, in this solar system. No doubt there are millions more in other solar systems.
Perhaps you mean "exoplanet"? That refers to any planet outside our Solar Systems.
They are in all three. Planets are in solar systems. There are lots of solar systems in a galaxy. There are lots of galaxies in the universe. So any planet is in a solar system, a galaxy and the universe.
Uranus is the third largest planet in the solar system.
They're rotating bodies, so... the moons around a planet would also be systems.
There are about 408 multiple-planet solar systems in our galaxy. The orientation of these solar systems are on a flat plane due to lacking giant planets, where as ours is tilted off the solar system's plane because of Jupiter's gravitational influence..
There are no double planet systems in our solar system. The closest to being considered a double planet are Pluto and its largest moon Charon, but since Charon is significantly smaller than Pluto, it is not classified as a double planet system.