Factual error: There are three major mistakes regarding gravity in the escape sequence in the asteroid field. Han and Chewie take the Millennium Falcon to refuge on an asteroid that, while visually huge, is still far too tiny to have sufficient gravity to allow humans to walk in anything like a normal fashion; yet, they walk normally both inside and outside of the ship. They also do not use pressurized suits outside of the ship, even though the asteroid's gravity should be far too weak to accumulate any significant atmospheric pressure; they use oxygen masks, but their blood should have boiled in near-zero atmospheric pressure. Finally, and most ridiculously, they fly straight down the giant cave worm's throat and land on the side of its throat (this is obvious in the shot where the Millennium Falcon lifts off and heads toward the toothy exit), and they get out and walk around on the side of its throat, which would mean the asteroid's gravity was impossibly perpendicular to its mass. (00:57:50)
Suggested correction: However, size isn't everything. The more mass an object has, the greater its gravitational field will be. Nothing is known of the asteroid's composition. It could have a high mass, resulting in a higher gravity than an equivalently sized body of lower mass. This would also address the atmosphere issue. Also, there is no evidence that the throat was vertical when they landed on it. Clearly, the creature was further down the tunnel perpendicular to the surface, then changed position as they flew out.