What stayed · The Machine28
The Grand Finale
What is a good death for a machine that has seen too much to be left wandering?
Illustration of atmospheric entry. Not a camera frame from inside the dive.
IllustrationBetween the world and the rings. Twenty-two dives, then the atmosphere.
The gap between Saturn’s clouds and the inner rings.
26 April 2017: Cassini begins 22 dives between Saturn’s clouds and the inner rings. 15 September 2017: it enters the atmosphere and is gone. The disposal is engineering ethics as much as spectacle. Enceladus has an ocean. Titan has organic seas. A dead spacecraft must not become an uninvited seed.
22
Two days before the plunge the wide-angle camera took one last full look. 13 September 2017. Eighty frames in just over two hours. Forty-two of those, red, green and blue, were stitched into the natural-color farewell: Saturn, the main rings, and six faint moons. Image scale on Saturn about 42 miles, 67 kilometers, per pixel. The last portrait of a world of rings is 42 frames wide.
Last full mosaic42 frames · 13 September 2017
DocumentaryNASA / JPL-Caltech / Space Science Institute. Cassini last full mosaic. Natural color from 42 frames of 80 acquired. Natural color from 42 red, green and blue wide-angle frames. 80 frames acquired; 42 used.
13 September 2017. Two days left. 42 red, green and blue wide-angle frames. Enceladus, Epimetheus, Janus, Mimas, Pandora and Prometheus make a faint appearance.MeasuredModeledExaggerated
Between the world and the ringsThen atmospheric entry. Disposal protected Enceladus and Titan.Represented: Abstracted path of Cassini’s 22 proximal orbits, 26 April–15 September 2017. Simplified: Not spacecraft telemetry. Gap width is opened for reading.Do the right thing even when the audience has gone home.
Why nextAstronomy first. History first. Saturn first. Only then: when does a light become an office?
The last mosaic, 42 frames, then 22 dives2
- NASA. Cassini-Huygens mission. Launch 15 October 1997; end 15 September 2017. https://science.nasa.gov/mission/cassini-huygens/. Consulted September 3, 2026.Saturn orbit 1 July 2004, Huygens landing 14 January 2005, Grand Finale 26 April–15 September 2017, 22 dives, 294 orbits, planetary-protection disposal.
- NASA / Cassini. A Farewell to Saturn. 13 September 2017; released 21 November 2017. https://science.nasa.gov/photojournal/a-farewell-to-saturn/. Consulted September 3, 2026.Last full mosaic of Saturn and the rings, two days before atmospheric entry. 80 wide-angle frames acquired; natural-color view constructed from 42 red, green and blue shots. Image scale on Saturn about 42 miles (67 km) per pixel.