ASTRONOMY PICTURE

OF THE DAY

SEPTEMBER 26, 2017

Cassini’s Last Ring Portrait at Saturn

EXPLANATION

How should Cassini say farewell to Saturn? Three days before plunging into Saturn’s sunny side, the robotic Cassini spacecraft swooped far behind Saturn’s night side with cameras blazing. Thirty-six of these images have been merged—by an alert and adept citizen scientist—into a last full-ring portrait of Cassini’s home planet for the past 13 years. The Sun is just above the frame, causing Saturn to cast a dark shadow onto its enormous rings. This shadow position cannot be imaged from Earth and will not be visible again until another Earth-launched spaceship visits the ringed giant. Data and images from Cassini’s mission-ending dive into Saturn’s atmosphere on September 15 continue to be analyzed.

Image Credit

NASA, JPL-Caltech, Space Science Institute, Mindaugas Macijauskas