Planets around the sun in nearly circular orbit . The radii of these orbits differ widely
When Worlds Collide.
Yes and No
They are in their own orbit
No, the planets do not leave their orbits and their orbits do not cross
No they each have its own orbit around the sun and they do not collide
As the planets orbit the sun, its gravity keeps them from colliding
No. As of current known orbital data, the Earth will never be in a position to collide with another planet.
It is possible for Earth and a star to collide with one another. However, the possibility is extremely remote.
In the early days of a solar system planetoids can collide with each other on a regular basis, but after the formation of regular planets with orbits, it would be hard to imagine a planetary collision. There would have to be a significantly influential gravitational force, perhaps from a passing star, to alter the orbit of a planet to set it on a collision course with another. We've seen examples of this with exoplanets, where one world's orbit was altered so much as to be made to orbit in the opposite direction of it's star's rotation.
The likelihood of Earth colliding with another planet in our solar system is extremely low due to the vast distances between planets and stable orbits. However, in the distant future, gravitational interactions between planets could potentially lead to collisions, but the probability is still very minimal.
Unless they turn into meteorites, and collide with the planets, pretty much not at all.