Planets around the sun in nearly circular orbit . The radii
of these orbits differ widely
The star TRAPPIST-1 has three known planets. Such planets are not easy to utterly destroy, unless they happen to fall into their star, or collide with one another (in which case they would presumably form a larger planet).
When Worlds Collide.
Yes and No
They are in their own orbit
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
(well in pics) but it really wont happen because earth is like a big magnet but the gravitational pull will not let the other planets collide with the earth or (even the sun) some say !!
No. As of current known orbital data, the Earth will never be in a position to collide with another planet.
No, Neptune and Uranus will never collide. Their orbits do not come anywhere near one another.
they affect one another's motion only when they collide.
In the past some planets or protoplanets did collide with each other. Indeed we believe that the Earth/Moon system was created by just such a collision. We can also see comets crashing into planets to this day. However, the solar system is now much more stable and the major planets now orbit the Sun (because of the Sun's gravity), each following their own orbital path. Each orbital path is separated by millions of miles and while the planets' gravities do tug one on another, this is not enough to destabilize the orbits.
That is conduction.