Asteroids are obstacles that act as hazards that can disrupt and damage ships.
While a ship executes a maneuver, if it moves through or overlaps an asteroid it rolls one attack die. On a result, the ship suffers one damage; on a result, it suffers one damage. Then the ship skips its Perform Action step this round. The Adaptive Ailerons maneuver of the TIE/sk Striker and the TIE Reaper is the exception to this, as FFG has explicitly stated that these ships do not skip their Perform Action step after they overlap a ship or asteroid.
While a ship is moving, but not executing a maneuver, if it moves through or overlaps an asteroid, it executes its move as normal but suffers the same effect as if it executed a maneuver through the asteroid.
While a ship is at range 0 of an asteroid it cannot perform attacks.