Since no one from Earth has visited another planet, and we have no indication that there is anyone on the other planets, Earth does not help other planets in any way. Why do you think there is something Earth does to help them- whoever them is.
Studying the earth helps scientists to understand other planets since the earth is part of the solar system. Scientists use the features of the earth to compare them with what other planets hold.
It can help by them comparing and contrasting.
Because it comes from other planets and earth is approx the same age as the other planets so they work it out bye the dust and how hot it is I think.
It can help us understand exactly why the Earth is fit to support life, while the planets we are capable of seeing are not.
The other planets do have gravity.
No. Earth's magnetic field only affects earth, not other planets.
yes, the earth and other planets revolve around the sun
Earth and the other planets are mostly made of rock.
Earth and the other planets are mostly made of rock.
The other planets actually do have seasons.
Astronomers have found Earth-sized planets in other solar systems.