Off the Top
We are losing our atmosphere out to space! But don’t worry; it’s happening very slowly. How does gas escape Earth’s gravitational and magnetic fields?
Amazing But True!
- Even gas has trouble escaping from Earth’s gravitational field.
- Tiny amounts of hydrogen and helium escape from the top of the atmosphere.
- One way to escape is to absorb energy from the sun.
- Similar processes may have helped Mars to lose its atmosphere billions of years ago.
With the links below, learn more about atmosphere loss. Then answer the following questions.
- Minute Earth, Our Atmosphere is Escaping: http://www.youtube.com/watch?v=e7ZqMTBwFVs
- Space.com, Mars Lost Most of Its Atmosphere Billions of Years Ago, Scientists Say: http://www.space.com/22013-mars-atmosphere-curiosity-rover-meteorites.html
- Why do hydrogen and helium, but not oxygen and nitrogen, escape from the atmosphere?
- What does a gas molecule need to escape from Earth’s gravity?
- How does a gas particle escape from Earth’s magnetic field?
- Mars has a smaller magnetic field that Earth so it can lose gases from the atmosphere. Why?
- If Mars lost its hydrogen from the top of its atmosphere, why would that make it the dry rocky planet it is today?