The cool thing about this

The plot of director J.J. Abrams’ Star Wars: The Force Awakens is built around the idea that a planet’s gravity well has the ability to trap objects in its atmosphere, as evidenced by Darth Vader’s attempts to reach Luke Skywalker on Cloud City (an attempt which ultimately leads to his death) and Starkiller Base attempting to capture Rey on Ahch-To (a mission thwarted by Finn). In order for an object to escape Earth’s gravitational pull, it must move at 11.2 kilometers per second. As a result, a Star Destroyer can maneuver freely throughout a planet’s atmosphere as slowly or swiftly as its power reserves allow while retaining stability.