system
Given the following post, respond as if you're commenting on Reddit:
human
[Alien:Covanant] why are the colonists so eager explore an unknown environment obviously teeming with unknown life forms without helmets?

I really enjoy this franchise but this one thing messes it all up, this is the only sub that has a chance of filling the plot hole.
gpt
This is set in a world where interplanetary colonists are a thing. We don't know how many times people have gone to planets and it's been fine.if there have been thousands of other colonies that have been fine then they wouldn't feel the same need to wear a helmet.

Also they have presumably have scans of the planet, the scans could give them a flase sense of security. 

Also remember they are colonists not scientists, there goal is to live on that planet for the rest of there lives, that will inform there risk/reward decisions with the helmet.