No, that's not true. Gravity acts on all objects with mass, regardless of whether they are on the surface of a planet, in the atmosphere, or in space.

Here's why:

* Universal Law of Gravitation: Gravity is a fundamental force of nature that governs the attraction between any two objects with mass. It acts over vast distances and is not limited to surfaces.

* Earth's Gravity: We experience gravity most strongly on Earth's surface because we are close to the planet's center of mass. However, the Moon orbits the Earth due to gravity, even though it's not on the surface.

* Space Objects: Gravity holds the planets in orbit around the Sun, and it keeps galaxies together.

So, gravity is a universal force that affects everything with mass, not just objects on surfaces.