This image from NASA’s Cassini mission to Saturn has been strewn across websites and newspapers around the world in the last few weeks. It shows Saturn in the foreground with its tell-tale rings, and off in the distance, two tiny dots. One of them is where we live; the other is our moon.

The image is actually a composite of 141 different pictures taken on one day, July 19, 2013, called The Day the Earth Smiled by planetary scientist Carolyn Porco. She’s head of imaging for Cassini at the Space Science Institute in Boulder.

Porco’s been called a modern-day Carl Sagan, after the very poetic astrophysicist. They actually worked closely together.

To hear from Porco on the story behind these images, her remarkable career and the uncertain future of planetary missions given NASA’s budget constraints, listen to the interview with Colorado Matters host Ryan Warner.