Question

A guided question about the mass of planetary atmospheres. This may sound like a tough thing to do, but it really isn't too bad. Of course you could look these up on the 'net but you'll need to show your work and reasoning to get points here.

1. What is the mass of the Earth's atmosphere? Here's one way to proceed:
   • The pressure of the atmosphere at sea level is 1000 mbar, which is approximately 1 kg / cm² (this is 14.7 lbs per square inch).
   • That means that the mass of the atmosphere above each square cm of the Earth is 1 kg
   • The radius of the Earth is 6,330 km. Since the area of a sphere is 4πr², you can calculate the area of the entire Earth's surface in km².
   • Finally, you know that 1 km² is 10¹⁰cm², so you can find the total mass of the Earth's atmosphere, in kilograms.
   • Note that just writing down an answer is not sufficient; you'll need to show how you figured it out.

Answer 1