Gravity :)
(Gravity also holds the outer planets tightly to the Sun.)
Gravity.
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.
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.
outer planets are gas giants whille inner planets are just rocky planets. that includes that outer planets have significant amount of mass than the inner planets