Gravity.
Gravity :) (Gravity also holds the outer planets tightly to the Sun.)
because of gravitational force of the earth is more in inner planet
Gravitational pull
none of the inner planets
The inner planets are Mercury, Venus, Earth, and Mars. They are "inner" because the are the first 4 planets from the Sun.
Yes, the inner planets—Mercury, Venus, Earth, and Mars—have relatively closely spaced orbits compared to the outer planets. Their orbits are tighter and more compact, primarily due to their proximity to the Sun. This results in shorter orbital periods and smaller average distances between their orbits compared to the larger, more distant orbits of the outer planets.
Inner planets
After the inner planets you get the outer planets.
the inner planets are sometimes called Terrestrial Planets
Inner planets are terrestrial planets outer are jovian planets
the inner planets
I hesitate to admit that I was raised on one of the inner planets. The inner planets are not gaseous, like the outer planets.