When jets are recovered, they approach the carrier from aft at a 3.5 degree glide slope.  The angle deck is 9.5 degrees offset of center, so that if a jet overshoots the arresting cables or "bolts", it can just fly off the end of the angle deck and back into the air.  Usually the aircraft try to catch arresting cable three (3), to be considered a successful landing.  Aircraft land on the deck at 170 miles per hour and when they catch a wire, they come to a complete stop within 3 seconds.  The "MEATBALL" above is controlled with help of LSO officers (aviators), who stand at the port aft end of the angle deck.  They control the lights on the Meatball.  If the approaching aircraft is right on path, i.e. his glide slope is correct, the Amber Lights will be straight in alignment with the row of green lights and be center.  If the approaching jet is too high, the amber lights will be "above" the row of green lights.  If the jets is too "low", their will be red "danger" lights lit below the row of green lights.  And finally, if the LSO deems the approach is too far off to be safe, the Vertical Red Lights will "blink" on the sides of the amber lights.  These blinking red lights indicate a dangerous "abort" condition.