A shield called atmosphere
Breathing Life: Earth's Atmosphere Picture our planet wrapped in an invisible, life-giving blanket that stretches from the ground beneath your feet to the edge of space. This is the atmosphere – a dynamic, ever-changing system that's been silently supporting life for billions of years...well, thank you dear! It is retained by Earth's gravity, so that it can stay with us and most of its mass (~98%) is below ~ 25km.