Taken by the STS-133 crew, there's a lot going on in this photograph. On the right, you can see a docked Russian Soyuz spacecraft, one of the space giants designed by the Korolyov Design Bureau back in the 1960s for the Soviet space program. The Soyuz is a series that has been used now for more than 45 yeas. On the left, a small portion of the International Space Station's Quest airlock and some solar array panels. The Soyuz docks to the ISS for up to six months at a time. The most interesting component of the photograph, though, might be the thin blue line of Earth's atmosphere seen in the distance as surrounded by the pitch blackness of space.

View more Pictures of the Day.

Image: NASA.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.