Imagine having a backyard telescope so powerful you could easily see details on another planet. NASA has such an instrument at Mars and recently pointed it at Earth! The result was a stunning portrait of the Earth and its Moon that is a stargazer's dream. Clearly visible are the west coast of South America, clouds in the atmosphere, and the blue expanse of ocean that makes our planet unique.
Perhaps someday humans living on Mars will have a powerful lens like the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter to look back at their home world and be mindful of the water-rich planet that makes life -- and space exploration -- possible.
Credit: NASA/JPL-Caltech/Univ. of Arizona