Asteroid

Sir, the possibility of successfully navigating an asteroid field is approximately 3,720 to 1.  -C3PO

Asteroids are a type of obstacle.

Moving Into and Through Asteroids
When a ship executes a maneuver in which either the maneuver template or the ship's base physically overlaps an asteroid token, follow these steps:
 * 1) Execute the maneuver as normal, but skip the "Perform Action" step.
 * 2) Roll one attack die. The ship suffers any damage or critical damage rolled.

Available Through
X-Wing Core Set