So much astrophysicists here i see...
Love reading people writing 'I'm an expert' - then quoting wiki!
The original poster is correct, with 1g or more (note this is g, not G, the universal constant - dur) you would expect a planet to have an atmosphere of some kind.
Real reason why most of the planets which should have atmospheres have none:
Atmospheric flight isn't available until later, or maybe Season 3.
Once every one of you part ways with another 30 quid, things will go back to the way it should be.
And the universe will right itself.
Just like what God said: Money talks and bullsh1t walks....
Yes indeed, however if the two were taken to court, then the electric Universe theory would win hands down because there is so much more evidence to support it than there is for the presently accepted theory coming from academia. Lots of the so called scientists teaching at places like Oxford and Cambridge are talking out of their collectiveon many subjects. All provable. It's the dogmatic approach that they adopt which prevents unbiased investigation. Have a quick look at Rupert Sheldrake to get a feel for whats going on.
https://www.youtube.com/watch?v=JKHUaNAxsTg
The answer is simple.
The Thargoids stole all the gases.
Prepare to go on a galaxy spanning mission in Season 3 - "The quest for missing gas" to solve the mystery.