NASA - National Aeronautics and Space Administration

Apollo 17 astronauts took this view of the full Earth on their trip to the moon in December 1972. Ever since NASA began leaving Earth's gravity 50 years ago, we've been looking back in awe at the place we all come home.

Whether simply highlighting the planet's beauty or studying its atmosphere, landmasses and climate systems, NASA's perspective continues to offer a unique look at our world.

Share your comments below on Earth and NASA's role in understanding it.