Indeed... And while on the topic of vacuum levels:
This is an uncensored photo of the Apollo 14 landing.
A Pfhor ship is clearly visible to the top right, and vacuum-enabled Pfhor Troopers, led by an armoured Hunter (left), are advancing on the human position. Their unprovoked attack was doomed from the start as the astronauts were all experienced Vid-Masters, and the Moon soon became awash with alien ichor.