Probably already been discused, just before my time, but here it goes:
1: Atmospheric Battle. All Obstacles still obstruct LoS and give the +1 defense bonus. They however are just thick clouds, so when a manuevre template or a ship crosses or ends on one, roll 1 attack dice, on a hit the ship loses it's action, or receives an Ion token, and on a critical it receives a stress token. No damage will apply. Further, as the ground is in the area, when a ship performs a red manuevre, roll 2(maybe 3) attack dice, if both(all) are criticals, the ship found the planet.....The hard way.
2: Asteroid Field: All obstacles are the same as standard play. There are 10 used and they may be placed anywhere on the board but at least range 1 from any board edge. The Asteroids move at speed 1 left to right or right to left, all use the same direction throughout the game. If one moves off the board edge another takes it's place on the opposite edge. They may be affected by a tractor beam.
3: Hide and Seek: one player is the Defender, the other the attacker. The attacker has initiative. The defender may set up as many asteroids as desired on the field. The attacker may attack the asteroids, any hit destroys it. The defender may only use small ships, the defender secretly puts a paper under the asteroids that his ships are hiding in. If an asteroid with a ship in it is destroyed so is the ship. The defender must reveal a ship on every even turn, until he is out of ships to reveal. The defender ignores the asteroid he is hiding in the turn he activates a hidden ship.