Astronaut Alex Gerst captured from ISS the Moon over Earth. The main part of Earth’s atmosphere is due to stratosphere which extends to 50km. From the image atmosphere looks thick but it only accounts for 0.8% of the Earth’s radius 6,371km.

Credit: Alex Gerst, ESA, NASA

Reference: Alex Gerst’s Tweet
See earthview photo gallery with web-globe: LiVEARTH