Here's why:

* Gravity is an intrinsic property of mass. A planet's gravity depends solely on its mass and its radius. The more massive a planet is, the stronger its gravitational pull.

* Distance affects the *force* of gravity between two objects. While the Sun's gravity weakens with distance, this doesn't change the planet's own gravity.

Think of it this way: Earth's gravity pulls you towards the center of the Earth, regardless of whether you're standing on the equator or at the North Pole. The distance from the Sun doesn't change the amount of gravity Earth itself exerts.

However, there is an indirect relationship:

* Planets further from the Sun are generally less massive. This is due to the way planets form in the early solar system. So, while the distance itself doesn't affect gravity, the planets that form further out often have less mass, leading to weaker gravity.

* A planet's *orbital speed* is affected by the Sun's gravity. Planets further from the Sun have slower orbital speeds because the Sun's gravitational pull is weaker at those distances.

Let me know if you have any other questions about gravity!