The atmosphere is what keeps all of the stuff on Earth that's not nailed down from flying off into space. Okay, that's not entirely true, gravity helps with that. But our atmosphere is very important too!
Earth's atmosphere is what helps regulate the planet's temperature and humidity. Our neighboring planets, Venus and Mars have atmospheres that are extremes compared to ours. Venus has a super thick atmosphere, trapping in heat making the planet the hottest in the solar system. Mars' atmosphere is weak, leaving the planet dusty and cold.
Our atmosphere compared to our neighbor Mars'
It's pretty big, I guess.
“Venus and Mars have atmospheres that are extremes”
That airplane can not be to scale, that thing is gigantic!
At great depths, pressure is measured in atmospheres.