NASA/JPL-Caltech/R. Hurt (SSC)
For a long time Saturn was hiding a secret
that only an IR telescope like Spitzer could see: a giant ring – far larger than Saturn's other orbital debris rings – so diffuse that it reflected very little sunlight back toward earth, making it invisible. Spitzer's IR instruments can capture the heat radiation put off by dust particles in the ring, which starts some 3.7 million miles from Saturn and extends outward another 7.4 million miles. "It's not often you get to show someone something completely new about a planet as well-known as Saturn," Hurt says. "Doing an artist's rendering that is designed to look like an infrared image I thought would help people to better understand that this ring can only be seen in the infrared."