All of the other planets have an orbital path that is within six degrees of the ecliptic. The celestial object formerly known as planet Pluto had an orbit that was about 17 degrees off the plane.
The ecliptic
Planets in the solar system which orbit the sun.
gravity?
The sun's gravity keeps them in orbit and prevents them from flying off into space. The planets travel quickly enough that they do not fall into the sun.
According to Keplers first law of 1618 which has not been repealed yet, the planets each move in an elliptical orbit with the Sun occupying one focus. The shape of an ellipse is described by the eccentricity. For low eccentricity such as the planets' orbits have, the orbit is very close to being a circle but the most significant difference is that the Sun is off-centre.
Pluto is not lost, its orbit is well understood and there are people who know exactly where it is on any given day. However Pluto has an orbit that is unusually eccentric, and is inclined by 17 degrees to the ecliptic. That means it is found well off the beaten track where the eight major planets can always be found, near the ecliptic.
The ecliptic
Eris is tilted at an angle of about 44 degrees to the ecliptic. Although it is considered a dwarf planet.
The position varies but if you look online or buy a planisphere you will see all planets follow the ecliptic path but aren't on the exact path. The planets are actually slightly off the ecliptic.
No; it's about 23 degrees off the plane of its orbit.
scientists are still discovering
The star Altair stays in one place in the sky, but Venus and Saturn move on (or near) a circle called the ecliptic, like the other planets. But none of the planets goes close to Altair because it is well off the ecliptic.
No, there is no scientific evidence that this is even possible.
At the moment it is about 5 degrees. It is slowly decreasing. Don't worry though, it will take thousands of years to change much.
Because the plane of the moon's orbit is approximately 5 degrees off the ecliptic, meaning when the moon slips past the sun it either goes over it or under it. If the moon's orbit was on the same plane as the ecliptic, then we would have a solar eclipse every month.
Planets in the solar system which orbit the sun.
The sun, does not orbit anything. Because it is the center of the universe, based off of the heliocentric model. Planets, and satelites(moons) do orbit the sun though.