It makes the Earth livable for us creatures. We get protected from the Sun's harmful rays reaching to Earth, which makes Earth feel comfortable. Atmosphere also contains Oxygen and we rely on that everyday.
Answer:
This is not a question we can answer, this is a question only you can answer because it is asking for your personal belief on wether alien's exist outside of earth or not.
Explanation:
It’s because they’re curious or they get peer pressured into doing it to “fit in.”