1. Gravity: This is the primary force acting upon the meteor. Earth's gravitational pull attracts the meteor, causing it to accelerate towards the planet. The strength of this force depends on the mass of the meteor and its distance from Earth.

2. Air Resistance (Drag): As the meteor enters Earth's atmosphere, it encounters air molecules. These molecules collide with the meteor, creating a force that opposes its motion. This force is called drag and increases dramatically as the meteor's speed increases.

3. Buoyancy: While less significant than gravity or drag, the air surrounding the meteor exerts a buoyant force, pushing it upwards. This force is relatively small due to the high density of the meteor compared to air.

4. Aerodynamic Lift: The shape of the meteor and its angle of entry can create a small amount of lift. This force can cause the meteor to slightly deviate from its trajectory.

5. Friction: The intense heat generated by friction between the meteor and the air molecules causes the surface of the meteor to melt and ablate. This ablation removes material and alters the shape of the meteor, further impacting the other forces acting upon it.

6. Electromagnetic Forces: While not as prominent as the other forces, electromagnetic interactions between the meteor and the Earth's atmosphere can play a role, especially as the meteor breaks apart.

7. Solar Radiation Pressure: This force is extremely weak but can affect the trajectory of very small meteors, especially during their initial stages of entry.

The combination of these forces determines the trajectory, speed, and ultimately the fate of a meteor as it travels through Earth's atmosphere.