why can't i sell gas?

[hexabal]

have you read the new rules?

[zxz_new]

If you play in Universe 1, see this

or just read this row

5. There will be asteroids but on the market you won't be able to trade gas for other resources Shipmarket included

[MartinNosovich]

You can sell gass only to other players. And, if you play in Uni1 - better keep it - in War universe you're just dead without gas.